Patent Description:
Lithium-ion batteries have become a popular power source choice due to their potential to provide a combination of cyclability, large capacity, and high power. Lithium-ion batteries may be used as power sources for mobile phones, laptop computers, electric vehicles, hybrid electric vehicles, and many other electronic apparatuses/machines.

A lithium-ion cell may include one or more positive electrodes (e.g., cathodes) and one or more negative electrodes (e.g., anode) separated by a polymeric separator. An electrolyte (e.g., organic) material may be provided within a battery casing. One or more current collectors connected to the positive or negative electrode carry charge or current from the battery to one or more external devices. Lithium-ion batteries may be charged and discharged through movement of lithium ions between the positive and negative electrodes.

<CIT> describes metal electrodes, more specifically, lithium-containing anodes, high performance electrochemical devices, such as secondary batteries, including the aforementioned lithium-containing electrodes, and methods for fabricating the same. In one implementation described therein, a rechargeable battery is provided. The rechargeable battery comprises a cathode film including a lithium transition metal oxide, a separator film coupled to the cathode film and capable of conducting ions, a solid electrolyte interphase film coupled to the separator, wherein the solid electrolyte interphase film is a lithium fluoride film or a lithium carbonate film, a lithium metal film coupled to the solid electrolyte interphase film and an anode current collector coupled to the lithium metal film.

<CIT> describes an electrochemical cell comprising an anodic current collector in contact with an anode. A cathodic current collector is in contact with a cathode. A solid electrolyte thin-film separates the anode and the cathode.

<CIT> describes a method and apparatus for forming metal electrode structures, more specifically lithium-containing anodes, high performance electrochemical devices, such as primary and secondary electrochemical devices, including the aforementioned lithium-containing electrodes. In one implementation described therein, the method comprises forming a lithium metal film on a current collector. The current collector comprises copper and/or stainless steel. The method further comprises forming a protective film stack on the lithium metal film, comprising forming a first protective film on the lithium metal film. The first protective film is selected from a bismuth chalcogenide film, a copper chalcogenide film, a tin chalcogenide film, a gallium chalcogenide film, a germanium chalcogenide film, an indium chalcogenide film, a silver chalcogenide film, a dielectric film, a lithium fluoride film, or a combination thereof.

<CIT> describes metal electrodes, more specifically lithium-containing anodes, high performance electrochemical devices, such as secondary batteries, including the aforementioned lithium-containing electrodes, and methods for fabricating the same. In one implementation described therein, an anode electrode structure is provided. The anode electrode structure comprises a current collector comprising copper. The anode electrode structure further comprises a lithium metal film formed on the current collector. The anode electrode structure further comprises a solid electrolyte interface (SEI) film stack formed on the lithium metal film. The SEI film stack comprises a chalcogenide film formed on the lithium metal film.

According to a first aspect of the invention, there is provided a method as defined in claim <NUM>. Optional and/or preferable features are defined in the dependent claims and through the detailed description below.

For a more complete understanding of this disclosure, and the advantages thereof, reference is now made to the following descriptions taken in conjunction with the accompanying drawings, in which:.

<FIG> each illustrate cross-sectional and plan views of an electrode workpiece <NUM> during an example process <NUM> for forming a battery electrode, according to certain embodiments of this disclosure. In general, process <NUM> for forming a battery electrode includes depositing a first layer of an electrode active material on a first portion of a surface of a substrate; forming a current collector by depositing, using a thin film deposition process, a conductive material on a surface of the first layer of the electrode active material and on a second portion of the surface of the substrate, potentially depositing a second layer of the electrode active material on a portion of a surface of the current collector, and removing the formed battery electrode (including the first layer of the electrode active material, the current collector, and (if formed) the second layer of the electrode active material) from the substrate. One or more applications of heat may be performed during process <NUM> to facilitate drying of the electrode active material and removal of the formed battery electrode from the substrate.

As illustrated in <FIG>, a first electrode active material layer 104a is deposited on a portion <NUM> of surface <NUM> of a substrate <NUM>. A portion <NUM> of surface <NUM> of substrate <NUM> remains free of the electrode active material of first electrode active material layer 104a.

Substrate <NUM> may include any suitable type of substrate on which a battery electrode may be formed. In certain embodiments, surface <NUM> of substrate <NUM> has a dewetting condition relative to the electrode active material of first electrode active material layer 104a (and potentially to the conductive material of a to-be formed current collector, described below). The dewetting condition may be that substrate <NUM> is hydrophobic, oleophobic, or both, which may assist with removing first electrode active material layer 104a (and potentially the to-be formed current collector, described below), and thereby the formed battery electrode, from substrate <NUM> during subsequent processing. As just a few examples, substrate <NUM> may include a polytetrafluoroethylene (PTFE) material, a polyethylene material, a polyphenol material, or any of a number of other hydrophobic and/or oleophobic materials, particularly at surface <NUM> of substrate <NUM>.

First electrode active material layer 104a may include the active material for either a positive electrode (e.g., a cathode) or a negative electrode (e.g., an anode) of a battery. To that end, depending on whether electrode workpiece <NUM> is being constructed into a cathode or anode, first electrode active material layer 104a also could be referred to as either a cathode active material layer or an anode active material layer, and the electrode active material of a cathode active material layer could be referred to as a cathode active material and the electrode active material of an anode active material layer could be referred to as an anode active material.

The electrode active material of first electrode active material layer 104a may include any material suitable for use as a cathode or an anode. In certain embodiments, the battery electrode being formed is to be used in a lithium-ion battery using a lithium-based chemistry. As just a few examples, for forming a cathode, the electrode active material of first electrode active material layer 104a may include a lithium oxide material (e.g., a lithium metal oxide), such as lithium cobalt oxide (LiCoO<NUM>), lithium iron phosphate (LiFePO), lithium manganese oxide (LiMn<NUM>O<NUM>), lithium nickel oxide (LiNiO<NUM>), or another suitable lithium oxide material. As just a few examples, for forming an anode, the electrode active material of first electrode active material layer 104a may include graphite, sodium, lithium, silicon, silicon oxide aluminum, tin, or the like. As just one particular example for a lithium-ion battery, the cathode active material may include a lithium oxide material while the anode active material may include graphite. In other embodiments, the battery may use chemistry such as a zinc-air, nickel-cadmium (NiCd), nickel-metal hydride (NiMH), lithium iron phosphate (LiFePO4), lithium-ion polymer (Li-ion polymer/LiPo), or the like, with appropriate electrode active materials for first electrode active material layer 104a.

First electrode active material layer 104a may be deposited in any suitable manner. In certain embodiments, first electrode active material layer 104a may be coated or otherwise formed on portion <NUM> of substrate <NUM>. As just a few examples, first electrode active material layer 104a may be deposited using a slot die coater, a doctor blade, or in any other suitable manner. In certain embodiments, first electrode active material layer 104a may be formed by chemical vapor deposition (CVD) (including, potentially, plasma enhanced CVD (PECVD)), physical vapor deposition (PVD), or another deposition process.

In an example cathode implementation, first electrode active material layer 104a may have an areal density of about <NUM> milligram per square centimeter (mg/cm<NUM>) to about <NUM>/cm<NUM>. In an example anode implementation, first electrode active material layer 104a may have an areal density of about <NUM> milligram per square centimeter (mg/cm<NUM>) to about <NUM>/cm<NUM>. In certain embodiments, first electrode active material layer 104a may be deposited to a thickness of about <NUM> micrometers (µm) to about <NUM>, potentially depending on the porosity and density of networks formed. In certain embodiments, some cathode materials, such as LiCoO<NUM> and the spinels, may be more lithium dense than anode materials (e.g., carbons) that may be used to allow sufficient charge/discharge. As another example, using pure lithium as an anode active material may allow active material layers as thin as a single atom. As another example, a current collector itself could act as the anode.

Although particular values are described, whether forming a cathode or an anode, this disclosure contemplates first electrode active material layer 104a having any suitable areal density and being deposited to any suitable thickness. The areal density and/or thickness of electrode active material layers may affect energy storage of a battery cell. To that end, to optimize electrode volume, electrode weight, and use of electrode active material, the areal density and/or thicknesses of the electrode active material layers for cathodes and anodes may be chosen so that the energy storage capabilities of the positive and negative electrodes substantially match.

In certain embodiments, the electrode active material of first electrode active material layer 104a includes an active component, a binding agent, and (during deposition) a solvent.

The active component may include the active element of the first electrode active material layer 104a. In the case of a cathode, the active component may include lithium oxide. In the case of an anode, the active component may include graphite. The binding agent may act as an adhesive that helps the active material and potentially other components (e.g., a conductive additive) rest on substrate <NUM>. In other words, the binding agent may help hold particles of the active component (and possibly a conductive additive) together to form first electrode active material layer 104a. As just one example, the binding agent may include polyvinylidene fluoride (PVDF). The binding agent may be inert. In certain embodiments, the components of the electrode active material of first electrode active material layer 104a are mixed using a solvent. The solvent may liquify the combination of these components for deposition. Example solvents include dimethyl sulfoxide (DMSO), ethanol, and the like. In certain embodiments, the electrode active material also includes a conductive additive, which may be a material added to increase conductivity of the battery electrode being formed. As an example, the conductive additive may be an organic material, such as carbon or carbon black. These components may be formed into a so-called slurry.

The components of the electrode active material of first electrode active material layer 104a may contribute to the capacity, energy, conductivity, and mechanical integrity of the battery electrode being formed. The various ratios of the components relative to one another may be selected to achieve an optimal combination of properties of the battery electrode. Moreover, the selection of solvent may affect which binding agents are suitable, and possibly whether additional additives are appropriate.

Although the electrode active material of first electrode active material layer 104a is described as including this particular content or taking this particular form or being deposited in particular manners, this disclosure contemplates the electrode active material of first electrode active material layer 104a including any suitable content and taking any suitable form and being deposited in any suitable manner, according to particular implementations. For example, although use of a solvent and formation into a slurry is described, the electrode active material of first electrode active material layer may be deposited using dry deposition techniques, if desired, and therefore the solvent may be omitted in such embodiments.

As illustrated in <FIG>, heat <NUM> may be applied to electrode workpiece <NUM>. For example, electrode workpiece <NUM> may be baked at a suitable temperature. Applying heat <NUM> to electrode workpiece <NUM> may serve a variety of purposes.

For example, applying heat <NUM> to electrode workpiece <NUM> may dry the electrode active material of first electrode active material layer 104a. In embodiments in which the electrode active material of first electrode active material layer 104a includes a solvent, heating the electrode active material of first electrode active material layer 104a may include drying, or evaporating, the solvent, which in turn may dry the electrode active material of first electrode active material layer 104a.

As another example, applying heat <NUM> to electrode workpiece <NUM> may facilitate partially or wholly releasing electrode workpiece <NUM> from substrate <NUM>. For example, due at least in part to the hydrophobic/oleophobic property of surface <NUM> of substrate <NUM>, applying heat <NUM> to electrode workpiece <NUM> may cause electrode workpiece <NUM> to essentially float on surface <NUM> of substrate <NUM>, which may assist with removing the formed battery electrode (including first electrode active material layer 104a and a to-be-formed current collector) from substrate <NUM> at a subsequent step of process <NUM>.

The appropriate temperature for heat <NUM> and time of exposure of electrode workpiece <NUM> to heat <NUM> may be specific to the surface area of first electrode active material layer 104a and the electrode active material of first electrode active material layer 104a. In certain embodiments, heat <NUM> may be about <NUM> to about <NUM> above the boiling point of the solvent in the electrode active material of first electrode active material layer 104a, and electrode workpiece <NUM> may be exposed to heat <NUM> for about <NUM> minutes to about <NUM> minutes.

Although heat <NUM> is shown as being applied over electrode workpiece <NUM>, this disclosure contemplates heat <NUM> being applied in any suitable direction or combination of directions. For example, heat <NUM> may be applied to substrate <NUM> and heat <NUM> may be applied over electrode workpiece <NUM>. Heat <NUM> may be applied in an oven, such as a vacuum drying oven or other suitable type of oven, or using any other suitable device.

As illustrated in <FIG>, a current collector <NUM> may be formed on electrode workpiece <NUM>. Current collector <NUM> includes a conductive material <NUM>. Current collector <NUM> may be formed by depositing conductive material <NUM> on surface <NUM> of first electrode active material layer 104a. For example, particles <NUM> of conductive material <NUM> may be deposited on surface <NUM> of first electrode active material layer 104a to form current collector <NUM>.

In certain embodiments, conductive material <NUM> is deposited over portions of electrode workpiece <NUM> such that current collector <NUM> extends over an edge of first electrode active material layer 104a. For example, conductive material <NUM> may be deposited along a sidewall surface <NUM> of first electrode active material layer 104a, and potentially on a portion <NUM> of surface <NUM> of substrate <NUM>, such that the current collector <NUM> extends along sidewall surface <NUM> of first electrode active material layer 104a and along portion <NUM> of surface <NUM> of substrate <NUM>. Portion <NUM> of surface <NUM> of substrate <NUM> may be adjacent to portion <NUM> of surface <NUM> of substrate <NUM>. Furthermore, although portion <NUM> is shown to be only a portion of portion <NUM> (see, e.g., <FIG>) of substrate <NUM>, conductive material <NUM> could be deposited to an edge of surface <NUM> of substrate <NUM>, if desired. In certain embodiment, conductive material <NUM> is deposited as a generally conformal, uniform layer over surface <NUM> of first electrode active material layer 104a, sidewall surface <NUM> of first electrode active material layer 104a, and portion <NUM> of surface <NUM> of substrate <NUM>.

To form current collector <NUM>, conductive material <NUM> may be deposited using any suitable thin film deposition process. A thin film deposition process may include a technique for creating and depositing thin film coatings onto a substrate material. For example, conductive material <NUM> may be deposited using a PVD process (e.g., a sputter deposition process), a CVD process, or another suitable type of thin film deposition process for depositing particles <NUM> of conductive material <NUM> on surface <NUM> of first electrode active material layer 104a, and potentially over an edge of first electrode active material layer 104a and onto portion <NUM> of surface <NUM> of substrate <NUM> and/or along sidewall surface <NUM> of first electrode active material layer 104a.

For example, a PVD process, and particularly a sputter deposition process, may include positioning substrate <NUM>, on which first electrode active material layer 104a has been deposited, in a vacuum chamber with a target layer of conductive material <NUM> positioned opposite substrate <NUM>. High energy particles of a suitable gas may be directed at the target layer, causing particles of the target layer to disengage from the target layer and move toward substrate <NUM> for depositing on surface <NUM> of first electrode active material layer 104a, as well as over an edge (edge <NUM>, labeled in <FIG>) of first electrode active material layer 104a on sidewall surface <NUM> of first electrode active material layer 104a and on portion <NUM> of surface <NUM> of substrate <NUM>. Example PVD processes include sputtering (e.g., magnetron (DC or RF) sputtering, ion beam sputtering, and the like), evaporation (e.g., electronic beam (e-beam) evaporation, ion-assisted deposition, thermal evaporation, and the like), cathodic arc vapor deposition, pulsed laser deposition, and the like.

As another example, a CVD process may include positioning substrate <NUM>, on which first electrode active material layer 104a has been deposited, in a vacuum chamber, and heating one or more volatile precursors, causing the one or more precursors for vaporize. When the vaporized precursor(s) interact with the substrate surface (that is the surface(s) on which deposition is desired), a chemical reaction occurs leaving a chemically-deposited coating. Example CVD processes include PECVD, atmospheric pressure CVD, low-pressure CVD, ultra-high vacuum CVD, atomic layer deposition, and the like.

In certain embodiments, if the battery electrode being formed using process <NUM> is a cathode, current collector <NUM> may be deposited using a PVD process (e.g., a sputter deposition process). In certain embodiments, if the battery electrode being formed using process <NUM> is an anode, current collector <NUM> may be deposited using a PVD process (e.g., a sputter deposition process) or a CVD process. That is, in certain embodiments, the materials suitable for use as a cathode and its associated current collector <NUM> may permit deposition via a PVD process (e.g., a sputter deposition process), while the materials suitable for use as an anode and its associated current collector <NUM> may permit deposition via a PVD process (e.g., a sputter deposition process) or a CVD deposition process. Additional details of an example process for sputter deposition are illustrated and described below with reference to <FIG>.

In one example, conductive material <NUM> may be aluminum and current collector <NUM> may be deposited using DC sputtering, e-beam evaporation, or cathodic arc vaporization. Taking a cathodic arc vaporization technique as an example, in certain embodiments, polarizations of about <NUM> V to about <NUM> V and current levels less than about <NUM> A may be used. In certain embodiments, a boron nitride or other suitable crucible may be used for a thermal evaporation process, and it may be desirable to maintain the active material on which the current collector <NUM> is being deposited (e.g., first electrode active material layer 104a) on a relatively cooler surface (e.g., about <NUM> to about <NUM>) to reduce or eliminate rapid binder decomposition. In another example, conductive material <NUM> may be copper and current collector <NUM> may be deposited using DC sputtering.

It should be understood that these techniques are provided as examples only, and this disclosure contemplates using any suitable thin film deposition technique for depositing any suitable type of conductive material <NUM>. In certain embodiments, the conductive material <NUM> of current collector <NUM> may be deposited according to guidance from the supplier of the conductive material <NUM> and/or the equipment used for performing the thin film deposition. As just one particular example, manufacturers such as the KURT J. LESKER COMPANY, AMERICAN VACUUM, VACUUM TECHNOLOGY INCORPORATED, VACUUM INSTRUMENTS, and the like may provide guidance as to suitable thin film deposition conditions and parameters for conductive materials, that may be suitable for depositing conductive material <NUM> of current collector <NUM> according to certain embodiments.

In certain embodiments, a portion of current collector <NUM> that is deposited on portion <NUM> of surface <NUM> of substrate <NUM> may be referred to as contact portion <NUM>. When positioned in a battery structure, contact portion <NUM> may be used to connect the battery electrode being formed using process <NUM> to other conductive elements of the battery structure. For example, contact portion <NUM> may be used to connect, directly or indirectly, the battery electrode being formed to other appropriate battery electrodes (e.g., cathodes to cathodes or anodes to anodes) of the battery structure and/or to a battery terminal of an appropriate polarity (positive or negative).

Current collectors <NUM> are formed of conductive material <NUM> to facilitate movement of current or electrons out of a battery structure that incorporates the battery electrode being formed. Current collector <NUM> may be formed of any suitable type of conductive material <NUM>. For example, conductive material <NUM> of current collector <NUM> may include copper, aluminum, gold, a metallic alloy, or another conductive material. In certain embodiments, the type of conductive material <NUM> for a current collector <NUM> may depend on a type of battery electrode (e.g., cathode or anode) being formed using process <NUM>. That is, in certain embodiments, a current collector <NUM> for a cathode may include a different conductive material <NUM> than a current collector <NUM> for an anode. For example, conductive material <NUM> for a current collector <NUM> of a cathode may be aluminum, while conductive material <NUM> for a current collector <NUM> of an anode may be copper.

In certain embodiments, using a thin film deposition technique may allow current collector <NUM> to be deposited to as thin as a monolayer. As a particular example that may be suitable for reliable operation of a battery electrode in a battery, current collector <NUM> may be deposited to a thickness of about <NUM> to about <NUM>. As a more particular example, current collector <NUM> may have a thickness of about <NUM> or less. Although particular values are described, this disclosure contemplates current collector <NUM> being deposited to any suitable thickness.

As illustrated in <FIG>, a second electrode active material layer 104b may be deposited on at least a portion of a surface <NUM> of current collector <NUM>. Some or all of contact portion <NUM> of current collector <NUM> may remain free of the electrode active material of second electrode active material layer 104b. Although first electrode active material layer <NUM> and second electrode active material layer 104b are shown to be largely aligned vertically, first electrode active material layer <NUM> and second electrode active material layer 104b might or might not be aligned vertically.

In certain embodiments, the electrode active material of second electrode active material layer 104b is the same as the electrode active material of first electrode active material layer 104a.

Second electrode active material layer 104b may be deposited in any suitable manner. In certain embodiments, second electrode active material layer 104b is deposited in a similar manner to a manner in which first electrode active material layer 104a was deposited. In other embodiments, second electrode active material layer 104b is deposited in a different manner than the manner in which first electrode active material layer 104a was deposited.

In this example, surface <NUM> of current collector <NUM> contacts second electrode active material layer 104b and an opposing surface <NUM> of current collector <NUM> contacts first electrode active material layer 104a.

In an example cathode implementation, second electrode active material layer 104b may have an areal density of about <NUM> milligram per square centimeter (mg/cm<NUM>) to about <NUM>/cm<NUM>. In an example anode implementation, second electrode active material layer 104b may have an areal density of about <NUM> milligram per square centimeter (mg/cm<NUM>) to about <NUM>/cm<NUM>. In certain embodiments, second electrode active material layer 104b may be deposited to a thickness of about <NUM> to about <NUM>, potentially depending on the porosity and density of networks formed. In certain embodiments, some cathode materials, such as LiCoO<NUM> and the spinels, may be more lithium dense than anode materials (e.g., carbons) that may be used to allow sufficient charge/discharge. As another example, using pure lithium as an anode active material may allow active material layers as thin as a single atom. As another example, a current collector itself could act as the anode.

Although particular values are described, whether forming a cathode or an anode, this disclosure contemplates second electrode active material layer 104b having any suitable areal density and being deposited to any suitable thickness. The areal density and/or thickness of electrode active material layers may affect energy storage of a battery cell. To that end, to optimize electrode volume, electrode weight, and use of electrode active material, the areal density and/or thicknesses of the electrode active material layers for cathodes and anodes may be chosen so that the energy storage capabilities of the positive and negative electrodes substantially match.

As illustrated in <FIG>, heat <NUM> may be applied to electrode workpiece <NUM>. In certain embodiments, application of heat <NUM> is similar to application of heat <NUM>. Again, applying heat <NUM> to electrode workpiece <NUM> may serve a variety of purposes.

For example, applying heat <NUM> to electrode workpiece <NUM> may dry the electrode active material of second electrode active material layer 104b. In embodiments in which the electrode active material of second electrode active material layer 104b includes a solvent, heating the electrode active material of second electrode active material layer 104b may include drying the solvent, which in turn may dry the electrode active material. In certain embodiments, heat <NUM> may be applied, at least in part, by baking electrode workpiece <NUM>.

As another example, applying heat <NUM> to electrode workpiece <NUM> may facilitate partially or wholly releasing current collector <NUM>, and particularly contact portion <NUM> of current collector <NUM>, from substrate <NUM>. For example, due at least in part to the hydrophobic/oleophobic property of surface <NUM> of substrate <NUM>, drying electrode workpiece <NUM> may cause electrode workpiece <NUM> (which now includes current collector <NUM>, a portion of which contacts surface <NUM> of substrate <NUM>) to essentially float on surface <NUM> of substrate <NUM>, which may assist with removing the formed electrode from substrate <NUM> at a subsequent step of process <NUM>.

The appropriate temperature for heat <NUM> and time of exposure of electrode workpiece <NUM> to heat <NUM> may be specific to the surface area of second electrode active material layer 104b, the electrode active material of second electrode active material layer 104b, the surface area of any uncovered current collector <NUM> (e.g., including contact portion <NUM>), and conductive material <NUM>. In certain embodiments, heat <NUM> may be about <NUM> to about <NUM> above the boiling point of the solvent in the electrode active material of second electrode active material layer 104b, and electrode workpiece <NUM> may be exposed to heat <NUM> for about <NUM> minutes to about <NUM> minutes.

Although heat <NUM> is shown as being applied over electrode workpiece <NUM>, this disclosure contemplates heat <NUM> as being applied in any suitable direction or combination of directions. For example, heat <NUM> may be applied to substrate <NUM> and heat <NUM> may be applied over electrode workpiece <NUM>. Heat <NUM> may be applied in an oven, such as a vacuum drying oven or other suitable type of oven, or using any other suitable device.

At this state, the combination of first electrode active material layer 104a, current collector <NUM>, and second electrode active material layer 104b may be considered a battery electrode, referenced below as battery electrode <NUM> (see, e.g., <FIG>).

As illustrated in <FIG>, battery electrode <NUM> has been removed from substrate <NUM>. In this example, battery electrode <NUM> includes first electrode active material layer 104a, current collector <NUM>, and second electrode active material layer 104b. In certain embodiments, contact portion <NUM> of current collector <NUM> extends in a direction <NUM> beyond edge <NUM> of first electrode active material layer 104a and in the first direction beyond edge <NUM> of second electrode active material layer 104b. In other words, contact portion <NUM> of current collector may be exposed current collector <NUM> that is free electrode active material so that battery electrode <NUM> may be electrically connected to other conductive elements of a battery structure.

Battery electrode <NUM> may be removed from substrate <NUM> in any suitable manner, such as by lifting using a suitable tool or machine. In certain embodiments, the heating of electrode workpiece <NUM>, as described above with reference to <FIG> and <FIG>, may facilitate removal of battery electrode <NUM> from substrate <NUM> by activating or otherwise promoting the dewetting property of substrate <NUM> relative to conductive material <NUM> of current collector <NUM> and/or the electrode active material of first electrode active material layer 104a.

In certain embodiments, as can be seen in the plan view of <FIG>, contact portion <NUM> of current collector <NUM> extends substantially an entire width <NUM> of battery electrode <NUM>, which may provide for more linear current flow along length of battery electrodes <NUM>. In other embodiments, contact portion <NUM> of current collector <NUM> extends less than width <NUM> of battery electrode <NUM>.

Although process <NUM> is described with two layers of electrode active material being formed on both surface <NUM> and surface <NUM> of current collector <NUM> (first electrode active material layer 104a and second electrode active material layer 104b), this disclosure contemplates forming any suitable number of electrode active material layers <NUM>. For example, this disclosure contemplates forming only first electrode active material layer 104a. In such an example, the formed battery electrode may be the first electrode active material layer 104a and current collector <NUM> formed in <FIG>, and the structure formed in <FIG> may be removed from substrate <NUM> without forming second electrode active material layer 104b. As another example, even in embodiments in which electrode active material layers <NUM> are to be formed on both surface <NUM> and surface <NUM> of current collector <NUM> (first electrode active material layer 104a and second electrode active material layer 104b), the first electrode active material layer 104a and current collector <NUM> formed in <FIG> may be removed from substrate <NUM> following the state shown in <FIG>, and second electrode active material layer 104b may be applied to surface <NUM> of current collector <NUM> following such removal in a suitable manner.

As described above, the battery electrode (e.g., battery electrode <NUM>) being formed using process <NUM> may be a cathode or an anode. Typically, preventing cross-contamination of the materials used for forming cathodes and the materials used for forming anodes is desirable to avoid potentially compromising the operation of a battery that incorporates the cathodes and anodes. In certain implementations, cathodes and anodes are formed in isolated (from each other) portions of a battery manufacturing facility to avoid such cross-contamination. Thus, process <NUM> could be performed for forming cathodes on a first substrate <NUM> (or set of first substrates <NUM>), and process <NUM> could be performed for forming anodes on a different second substrate <NUM> (or set of second substrates <NUM>). Of course, process <NUM> could be repeated numerous times for forming multiple cathodes and anodes.

Additionally, although a single battery electrode <NUM> has been referenced in describing process <NUM>, this disclosure contemplates the materials deposited on substrate <NUM>, and substrate <NUM> having a large enough area to accommodate, forming multiple battery electrodes <NUM> in an electrode sheet and then subsequently cutting the formed electrode sheet into separate battery electrodes <NUM>. An example of such an electrode sheet and associated cutting is described below with reference to <FIG>.

<FIG> illustrates an example electrode sheet <NUM> in the process of being cut to form a plurality of battery electrodes 136a-136c, according to certain embodiments. Electrode sheet <NUM> may be formed using process <NUM>. In other words, although <FIG> are described with reference to forming a single battery electrode <NUM>, the formed battery electrode <NUM>, as removed from substrate <NUM>, may be formed as part of an electrode sheet <NUM> of sufficient dimensions to then be cut into a plurality of battery electrodes 136a-136c.

Electrode sheet <NUM> may have a width <NUM>. Depending on width <NUM> of electrode sheet <NUM> and an electrode width <NUM> (one of which is marked in <FIG>), a suitable number of blades <NUM> may be used to cut electrode sheet <NUM> into a particular number of electrodes. Although described as blades, blades <NUM> may take any form suitable for cutting electrode sheet <NUM>. This cutting process may be referred to as "slitting.

<FIG> illustrates an example sputtering process <NUM> for forming a current collector <NUM> on a layer of battery electrode active material, according to certain embodiments. In particular, <FIG> illustrates using sputtering process <NUM> to form current collector <NUM> on surface <NUM> of first electrode active material layer 104a, as well as over an edge <NUM> of first electrode active material layer 104a such that current collector <NUM> is formed on sidewall surface <NUM> of first electrode active material layer 104a and on portion <NUM> of surface <NUM> of substrate <NUM>.

Substrate <NUM>, on which first electrode active material layer 104a has been disposed, may be positioned in a deposition chamber <NUM> of a deposition tool. Deposition chamber <NUM> may be a vacuum chamber. A gas inlet <NUM> may be fed a substance <NUM> and may eject particles of substance <NUM> in a high-energy state in a direction <NUM> toward target layer <NUM>, positioned inside deposition chamber <NUM>. Target layer <NUM> may include conductive material <NUM>, which is to be deposited on surface <NUM> of first electrode active material layer 104a, as well as over edge <NUM> of first electrode active material layer 104a on sidewall surface <NUM> of first electrode active material layer 104a and on portion <NUM> of surface <NUM> of substrate <NUM>.

As particles of substance <NUM> collide with a surface <NUM> of target layer <NUM>, particles <NUM> of conductive material <NUM> may disengage from surface <NUM> of target layer <NUM>. At least some of particles <NUM> of conductive material <NUM> that have disengaged from surface <NUM> of target layer <NUM> may move toward and be deposited on surface <NUM> and sidewall surface <NUM> of first electrode active material layer 104a and portion <NUM> of surface <NUM> of substrate <NUM>, resulting in formation of current collector <NUM> (see, e.g., <FIG>).

The selection of substance <NUM> may be determined, at least in part, based on conductive material <NUM> of target layer <NUM>. In certain embodiments, an appropriate substance <NUM> is argon (Ar); however, any appropriate substance <NUM> may be used. As described above, conductive material <NUM> of target layer <NUM> may be aluminum, copper, or any other conductive material suitable for use as a current collector <NUM> for the type of battery electrode being formed.

<FIG> illustrates an example battery structure <NUM> having a single cathode-anode pair, according to certain embodiments. Battery structure <NUM> may be a complete battery or a battery cell that is part of a larger battery, for example. In the illustrated example, battery structure <NUM> includes a cathode <NUM> and an anode <NUM>. Cathode <NUM>, anode <NUM>, or both may be constructed using process <NUM> described above with reference to <FIG>. For example, cathode <NUM> may represent an instance of process <NUM> in which the formed battery electrode <NUM> of <FIG> is a cathode, and anode <NUM> may represent an instance of process <NUM> in which the formed battery electrode <NUM> of <FIG> is an anode.

In constructing battery structure <NUM>, cathode <NUM> is disposed to a first side of a separator <NUM>, and anode <NUM> is disposed to a second side of separator <NUM>. Separator <NUM> electrically insulates cathode <NUM> from anode <NUM> and provides ion exchange between cathode <NUM> and anode <NUM> in battery structure <NUM>. Separator <NUM> may be, in part, a film or other structure formed from a polymer, such as a polyolefin, polyethylene, polypropylene, or another suitable material.

For cathode <NUM>, cathode active material layers <NUM> are disposed on opposing sides of a cathode current collector <NUM>. Cathode active material layers <NUM> are analogous to electrode active material layers 104a and 104b of <FIG>, and cathode current collector <NUM> is analogous to current collector <NUM> of <FIG>. Furthermore, cathode current collector <NUM> includes contact portion <NUM>, which extends from ends of cathode active material layers <NUM> and is analogous to contact portion <NUM> of battery electrode <NUM> (see, e.g., <FIG>).

Similarly, for anode <NUM>, anode active material layers <NUM> are disposed on opposing sides of an anode current collector <NUM>. Anode active material layers <NUM> are analogous to electrode active material layers 104a and 104b of <FIG>, and anode current collector <NUM> is analogous to current collector <NUM> of <FIG>. Furthermore, anode current collector <NUM> includes contact portion <NUM>, which extends from ends of anode active material layers <NUM> and is analogous to contact portion <NUM> of battery electrode <NUM> (see, e.g., <FIG>).

In the illustrated example, contact portion <NUM> of cathode current collector <NUM> is coupled to a first battery terminal <NUM> of a first polarity (e.g., positive), and contact portion <NUM> of anode current collector <NUM> is coupled to a second battery terminal <NUM> of an opposite second polarity (e.g., negative). Contact portions <NUM> and <NUM> may be coupled to battery terminals <NUM> and <NUM>, respectively, directly or via any suitable intervening conductive structures. Furthermore, although contact portions <NUM> and <NUM> are shown to extend from ends of cathode <NUM> and anode <NUM>, respectively, that face the same direction, contact portion <NUM> of cathode current collector <NUM> could extend from cathode <NUM> in a first direction, while contact portion <NUM> of anode current collector <NUM> could extend from anode <NUM> in a different (and not necessarily opposite) direction.

Battery structure <NUM> may include a casing <NUM> that encases components of battery structure <NUM>, and may be provided to protect and insulate the internal components of battery structure <NUM>. Battery terminals <NUM> and <NUM> may be positioned, at least partially, external to casing <NUM> and/or may be at least partially integral to casing <NUM>. Furthermore, while first battery terminal <NUM> and second battery terminal <NUM> are shown to be positioned on a particular surface and on a same surface of casing <NUM>, this disclosure contemplates other arrangements.

Casing <NUM> may be formed of an insulating material, polymer, shrink wrap, or the like. Casing <NUM> may be hard or soft, and which is appropriate may depend on a form factor of battery structure <NUM>. For example, battery structure <NUM> may take any suitable form factor, such as a cylindrical form factor, a prismatic form factor, or a pouch form factor. In certain embodiments, a hard casing <NUM> may be used for a cylindrical or prismatic form factor, while a soft casing <NUM> may be used for a pouch form factor.

An electrolyte may be provided to facilitate ion exchange between the cathode <NUM> and anode <NUM> through the separator <NUM>. Casing <NUM> may be provided, in part, to enclose the electrolyte. In some embodiments, the electrolyte may be a gel or liquid material such as a polymer gel comprising lithium ion complexes such as ethylene carbonate, diethyl carbonate or the like and a non-coordinating anion salts such as lithium hexafluorophosphate (LiPF<NUM>), lithium hexafluoroarsenate monohydrate (LiAsF<NUM>), lithium perchlorate (LiClO<NUM>), lithium tetrafluoroborate (LiBF<NUM>), and lithium triflate (LiCF<NUM>SO<NUM>) or the like. In other embodiments, the electrolyte may be a solid electrolyte or an aqueous electrolyte.

<FIG> illustrates an example battery structure <NUM> having multiple cathode <NUM> and multiple anodes <NUM>, according to certain embodiments. In the illustrated example, battery structure <NUM> includes cathodes 402a-402n and anodes 404a-404n in an alternating, potentially stacked, arrangement, so each cathode <NUM> is adjacent to an anode <NUM>, but separated by separator <NUM>. Similarly, each anode <NUM> is adjacent to a cathode <NUM>, and separated by separator <NUM>. Thus, each cathode <NUM> is separated from any adjacent anode <NUM> by a separator <NUM>, and each anode <NUM> is separated from any adjacent cathode <NUM> by a separator <NUM>.

Separator <NUM> may be a continuous layer provided throughout battery structure <NUM>, arranged in a folding, "accordion" manner between cathodes <NUM> and anodes <NUM>, or may be discontinuous with distinct layers of separator <NUM> provided between cathodes <NUM> and anodes <NUM>. In other embodiments, the separator <NUM> may be rolled into a spiral.

Cathodes <NUM> include cathode current collectors <NUM>, and anodes include anode current collectors <NUM>. Cathode current collectors <NUM> include contact portions <NUM>, and anode current collectors <NUM> include contact portions <NUM>. Contact portions <NUM> of cathode current collectors <NUM> and contact portions <NUM> of anode current collectors <NUM> extend, in this example, past edges of separator <NUM>.

In general, like-numbered elements of battery structure <NUM> of <FIG> and battery structure <NUM> of <FIG> share certain features in common, and thus the description of those elements is not repeated with reference to <FIG>.

Battery structure <NUM> includes cathode connection structure <NUM> and anode connection structure <NUM>. Cathode connection structure <NUM> provides a conductive path to battery terminal <NUM> having a first polarity (e.g., positive), and anode connection structure <NUM> provides a conductive path to battery terminal <NUM> having a second polarity (e.g., negative). For example, contact portions <NUM> of cathode current collectors <NUM> may be coupled to cathode connection structure <NUM> to provide current flow to/from battery terminal <NUM>, and contact portions <NUM> of anode current collectors <NUM> may be coupled to anode connection structure <NUM> to provide current flow to/from battery terminal <NUM>.

In certain embodiments, each contact portion <NUM>/<NUM> is individually attached to an appropriate connection structure <NUM>/<NUM>, and may be attached to the appropriate connection structure <NUM>/<NUM> by crimping, spot welding, soldering, ultrasonic welding, using a connector such as a rivet, bolt, screw, adhesive, or the like. In some embodiments, the contact portion <NUM>/<NUM> may be bent, and the bent portion may be attached to the appropriate connection structure <NUM>/<NUM>. Connection structures <NUM>/<NUM> may, in certain embodiments, be a conductive material.

In certain embodiments, some or all of contact portions <NUM> of cathode current collectors <NUM> may be coupled together prior to coupling to cathode connection structure <NUM> and then coupled to cathode connection structure <NUM> as a group. For example, some or all of contact portions <NUM> of cathode current collectors <NUM> may be bonded to each other, and then bonded to, or placed in contact with, cathode connection structure <NUM>. The contact portions <NUM> may be attached to each other by crimping, spot welding, soldering, ultrasonic welding, using a connector such as a rivet, bolt, screw, adhesive, or the like, and then may be attached to cathode connection structure <NUM> using a similar or different process for providing electrical conductivity between the contact portions <NUM> and cathode connection structure <NUM>.

In certain embodiments, some or all of contact portions <NUM> of anode current collectors <NUM> may be coupled together prior to coupling to anode connection structure <NUM> and then coupled to anode connection structure <NUM> as a group. For example, some or all of contact portions <NUM> of anode current collectors <NUM> may be bonded to each other, and then bonded to, or placed in contact with, anode connection structure <NUM>. The contact portions <NUM> may be attached to each other by crimping, spot welding, soldering, ultrasonic welding, using a connector such as a rivet, bolt, screw, adhesive, or the like, and then may be attached to anode connection structure <NUM> using a similar or different process for providing electrical conductivity between the contact portions <NUM> and anode connection structure <NUM>.

While contact portions <NUM>, <NUM> in <FIG> and <FIG> are shown to be relatively large in comparison to the rest of the battery structures <NUM>, <NUM>, contact portions <NUM>, <NUM> may be sized according to the requirements for connecting contact portions <NUM>, <NUM> to each other or to connection structures <NUM>, <NUM>. After bonding or electrical connection to each other or to a connection structure <NUM>, <NUM>, contact portions <NUM>, <NUM> act as a positive terminal or a negative terminal. In certain embodiments, contact portions <NUM>, <NUM> may extend past the edges of the separators <NUM> by a distance of about <NUM>, and in other embodiments, different lengths may be used. Additionally, some of or all contact portions <NUM>, <NUM> may have a different lengths.

In another embodiment, one or more of cathode connection structure <NUM> or anode connection structure <NUM> may be omitted and contact portions <NUM>/<NUM> may be coupled directly to an appropriate battery terminal <NUM> or <NUM>.

As with battery structure <NUM> of <FIG>, battery structure <NUM> may include casing <NUM>. Furthermore, as with battery structure <NUM> of <FIG>, an electrolyte may be provided in battery structure <NUM> to facilitate ion exchange between the cathode <NUM> and anode <NUM> through the separator <NUM>. The description of such an electrolyte provided with reference to battery structure <NUM> is incorporated by reference into this description of battery structure <NUM>.

<FIG> illustrates an example method <NUM> for forming a battery electrode, according to certain embodiments. In certain embodiments, method <NUM> is generally analogous to process <NUM>. At block <NUM>, a substrate <NUM> is provided. Surface <NUM> of substrate <NUM> may have a dewetting condition relative to a to-be-deposited electrode active material and/or conductive material of a current collector. For example, surface <NUM> of substrate <NUM> may be hydrophobic and/or oleophobic.

At blocks <NUM>-<NUM>, one or more battery electrodes <NUM> may be formed on substrate <NUM>. In certain embodiments, a single battery electrode <NUM> is formed on substrate <NUM>. In other embodiments, as removed from substrate <NUM>, battery electrode <NUM> is part of an electrode sheet <NUM>, and method <NUM> further includes cutting electrode sheet <NUM> to form multiple battery electrodes <NUM>.

At block <NUM>, a first electrode active material layer 104a is deposited on a portion <NUM> of surface <NUM> of substrate <NUM>. In certain embodiments, the battery electrode <NUM> being formed is a cathode, and the electrode active material of first electrode active material layer 104a is a material suitable for use as a cathode. As just one example, a material suitable for use as a cathode may include lithium oxide. In certain embodiments, the battery electrode <NUM> being formed is an anode, and the electrode active material of first electrode active material layer 104a is a material suitable for use as an anode. As just one example, a material suitable for use as an anode may include graphite. In certain embodiments, during deposition, the electrode active material of first electrode active material layer 104a includes an active component, a binding agent, and a solvent.

At block <NUM>, substrate <NUM> and first electrode active material layer 104a may be heated by applying heat <NUM>. This heating, which may be performed by baking or otherwise applying heat <NUM> to substrate <NUM> and first electrode active material layer 104a, may dry the electrode active material of first electrode active material layer 104a. For example, in embodiments in which the electrode active material of first electrode active material layer 104a includes (during deposition) a solvent, heating the electrode active material may dry the solvent, thereby drying first electrode active material layer 104a. This heating also may facilitate partially or wholly releasing first electrode active material layer 104a from substrate <NUM>, which may assist with subsequently removing the formed battery electrode from substrate <NUM>.

At block <NUM>, a current collector <NUM> that includes a conductive material <NUM> may be formed using a thin film deposition process. For example, forming current collector <NUM> may include depositing, using a thin film deposition process, conductive material <NUM> on surface <NUM> of first electrode active material layer 104a. In certain embodiments, conductive material <NUM> is deposited over edge <NUM> of first electrode active material layer 104a and onto sidewall surface <NUM> of first electrode active material layer 104a and onto portion <NUM> of surface <NUM> of substrate <NUM>. In certain embodiments, current collector <NUM> has a thickness of about <NUM> to about <NUM>.

The thin film deposition process may include a PVD process (e.g., a sputter deposition process), a CVD process (including, possibly, a PECVD process), or another suitable thin film deposition process. In certain embodiments, when forming a cathode, current collector <NUM> may be formed by depositing conductive material <NUM> using a PVD deposition process. In certain embodiments, when forming an anode, current collector <NUM> may be formed by depositing conductive material <NUM> using a PVD deposition process or a CVD process.

In one example, forming current collector <NUM> includes depositing, using a sputter deposition process, conductive material <NUM> on surface <NUM> of first electrode active material layer 104a, and potentially over edge <NUM> of first electrode active material layer 104a and onto sidewall surface <NUM> of first electrode active material layer 104a and onto portion <NUM> of surface <NUM> of substrate <NUM>. In certain embodiments, the sputter deposition process includes directing a substance <NUM> at a target layer <NUM> to cause particles <NUM> of target layer <NUM> to disengage from target layer <NUM> and be deposited onto surface <NUM> of first electrode active material layer 104a, and potentially onto sidewall surface <NUM> of first electrode active material layer 104a and onto portion <NUM> of surface <NUM> of substrate <NUM>. Target layer <NUM> may include conductive material <NUM>.

At block <NUM>, after forming current collector <NUM> and before removing battery electrode <NUM> from substrate <NUM>, a second electrode active material layer 104b may be deposited on at least a portion of surface <NUM> of current collector <NUM>. Surface <NUM> of current collector <NUM> may contact second electrode active material layer 104b, and surface <NUM> of current collector <NUM> may contact first electrode active material layer 104a. Second electrode active material layer 104b may include the same electrode active material as was included in first electrode active material layer 104a.

At block <NUM>, substrate <NUM>, first electrode active material layer 104a, current collector <NUM>, and second electrode active material layer 104b may be heated by applying heat <NUM>. This heating, which may be performed by baking or otherwise applying heat <NUM> to substrate <NUM>, first electrode active material layer 104a, current collector <NUM>, and second electrode active material layer 104b, may dry the electrode active material of second electrode active material layer 104b. For example, in embodiments in which the electrode active material of second electrode active material layer 104b includes (during deposition) a solvent, heating the electrode active material may dry the solvent, thereby drying second electrode active material layer 104b. This heating also may facilitate partially or wholly releasing from substrate <NUM> the portion of current collector <NUM> that contacts surface <NUM> of substrate <NUM>, which may assist with subsequently removing the formed battery electrode from substrate <NUM>.

At block <NUM>, the formed battery electrode <NUM> may be removed from substrate <NUM>. Removing battery electrode <NUM> from substrate <NUM> may be facilitated by the dewetting condition of surface <NUM> of substrate <NUM> relative to the conductive material of current collector <NUM> and the electrode active material. A portion of current collector <NUM> extends in a direction <NUM> beyond edge <NUM> of first electrode active material layer 104a and in direction beyond edge <NUM> of second electrode active material layer 104b.

In example method <NUM>, battery electrode <NUM> includes current collector <NUM> and two layers of electrode active material, one on each of surfaces <NUM> and <NUM> of current collector <NUM>. In another example, only first electrode active material layer 104a is formed and the combination of first electrode active material layer 104a and current collector <NUM> is removed from substrate <NUM> following the heating of block <NUM> (the heating being performed to activate the dewetting condition of surface <NUM> of substrate <NUM> relative to conductive material <NUM>).

Method <NUM> may be repeated to form additional battery electrodes of the same type (e.g., cathodes or anodes) and/or to form battery electrodes of the other type (e.g., cathodes or anodes). The additional electrodes might be formed using the same or a different substrate <NUM>.

<FIG> illustrates an example method <NUM> for assembling a battery structure, according to certain embodiments. As examples, the battery structure being formed using method <NUM> could be battery structure <NUM> or battery structure <NUM>.

At block <NUM>, one or more cathodes <NUM> are formed, and at block <NUM> one or more anodes <NUM> are formed. Cathodes <NUM> and anodes <NUM> may be formed using process <NUM> and/or method <NUM>. Furthermore, cathodes <NUM> may be formed individually or as part of an electrode sheet <NUM> that is subsequently cut to form individual cathodes <NUM>. Similarly, anodes <NUM> may be formed individually or as part of an electrode sheet <NUM> that is subsequently cut to form individual anodes <NUM>.

At block <NUM>, one or more separators <NUM> are provided.

At block <NUM>, a battery structure is assembled using the one or more cathodes <NUM>, one or more anodes <NUM>, and one or more separators <NUM>. For example, the battery structure may be similar to battery structures <NUM> or <NUM>, described above. In certain embodiments, assembling the battery structure includes positioning the cathodes <NUM> and anodes <NUM> on opposing sides of separator <NUM> such that cathodes <NUM> are separated from adjacent anodes <NUM> by separator <NUM> and anodes <NUM> are separated from adjacent cathodes <NUM> by separator <NUM>. The battery structure may be stacked, rolled, folded, or assembled in another suitable manner. Current collectors <NUM> of cathodes <NUM> may be coupled in a suitable manner to a positive battery terminal <NUM>, and current collectors of anodes <NUM> may be coupled in a suitable manner to a negative battery terminal <NUM>. The cathode(s) <NUM>, anode(s) <NUM>, and separator <NUM> may be encased in a battery casing of a suitable type for the battery structure being formed (e.g., cylindrical, prismatic, or pouch). An electrolyte may be added within the battery casing.

The battery electrodes and battery structures described herein may be used for a variety of electronic devices and load. In some embodiments, the electronic device is a vehicle such as a rotorcraft, and the load is a device of the rotorcraft, such as a power converter, which may be part of an engine or propulsion unit of the rotorcraft.

<FIG> illustrates aspects of an example rotorcraft <NUM>, according to certain embodiments. Rotorcraft <NUM> includes rotor blades <NUM>, a powertrain <NUM>, a fuselage <NUM>, landing gear <NUM>, an empennage <NUM>, and rotorcraft computers <NUM>. It should be appreciated that some of teachings from rotorcraft <NUM> may apply to aircraft other than rotorcraft, such as airplanes, tilt rotor aircraft, unmanned aircraft, and the like.

Rotor blades <NUM> include main rotor blades 810a and tail rotor blades 810b. Powertrain <NUM> rotates main rotor blades 810a and optionally the tail rotor blades 810b. Powertrain <NUM> includes one or more engines <NUM>, a rotor mast <NUM>, and a drive shaft <NUM>. Engines <NUM> supply torque to the rotor mast <NUM> via drive shaft <NUM> to rotate main rotor blades 810a. Engines <NUM> may also supply torque to drive shaft <NUM> to rotate tail rotor blades 810b.

Fuselage <NUM> represents the body of rotorcraft <NUM> and is coupled to powertrain <NUM> such that powertrain <NUM> and rotor blades <NUM> move fuselage <NUM> through the air during operation. Landing gear <NUM> supports rotorcraft <NUM> when rotorcraft <NUM> is grounded. Empennage <NUM> represents the tail section of the aircraft and is connected to tail rotor blades 810b. Powertrain <NUM> and tail rotor blades 810b may collectively provide thrust in the same direction as the rotation of main rotor blades 810a, so as to counter torque effects created by main rotor blades 810a.

The rotorcraft <NUM> includes flight control devices operable to change the flight characteristics of rotorcraft <NUM>. The flight control devices can be part of rotor blades <NUM>, powertrain <NUM>, fuselage <NUM>, and the like. The flight control devices include mechanical and/or electrical systems operable to change, e.g., the positions or angle of attack of rotor blades <NUM>, the power output of engines <NUM>, and the like. In some embodiments, the flight control devices include a swashplate for collectively or cyclically controlling the pitch of each of main rotor blades 110A in order to selectively control direction, thrust, and lift of rotorcraft <NUM>. In some embodiments, the flight control devices include a tail rotor actuator for collectively controlling the pitch of tail rotor blades 810b in order to selectively control yaw of rotorcraft <NUM>. In some embodiments, the flight control devices include an engine control computer for selectively varying the power output of engines <NUM>. Other examples of flight control devices include horizontal or vertical stabilizers, rudder, elevators, or other control or stabilizing surfaces that are used to control or stabilize flight of rotorcraft <NUM>.

Rotorcraft computers <NUM> are operable to collect data about, or control flight of, rotorcraft <NUM>. In some embodiments, rotorcraft <NUM> is a fly-by-wire (FBW) rotorcraft, and rotorcraft computers <NUM> include flight control computers (FCCs) operable to execute one or more control laws (CLAWS) that control flight of rotorcraft <NUM>. For example, rotorcraft computers <NUM> can send electrical signals to engines <NUM>, the actuators for the swashplate, the tail rotor actuators, or the like to control flight of rotorcraft <NUM>. Rotorcraft computers <NUM> may be operable to perform sensor data collection and analysis as part of a health and usage monitoring system (HUMS), a flight control system, a sensor system, a monitoring system, or the like.

<FIG> is a block diagram of aspects of example rotorcraft <NUM>, according to certain embodiments. Specifically, features for controlling flight of rotorcraft <NUM> are shown. Rotorcraft computers <NUM> can be part of a flight control system used to control flight control devices <NUM> (described above), thus controlling flight of rotorcraft <NUM>. Rotorcraft computers <NUM> receive input signals from multiple sources, such as pilot flight controls <NUM> and aircraft sensors <NUM>. Based on the input signals, rotorcraft computers <NUM> transmit control signals to flight control devices <NUM>, which in certain embodiments may be an engine control computer of an engine.

Pilot flight controls <NUM> include manual controls that a pilot may manipulate to control flight of rotorcraft <NUM>. Examples of pilot flight controls <NUM> include a cyclic stick, a collective stick, pedals, and the like. In some embodiments, one or more of pilot flight controls <NUM> include trim motors, which rotorcraft computers <NUM> can command to move to a particular position, thereby providing flight control suggestions to the pilot.

Aircraft sensors <NUM> include sensors for measuring a variety of rotorcraft systems, flight parameters, environmental conditions and the like. For example, aircraft sensors <NUM> may include sensors for measuring airspeed, altitude, attitude, position, orientation, temperature, airspeed, vertical speed, and the like. Other aircraft sensors <NUM> could include sensors relying upon data or signals originating external to rotorcraft <NUM>, such as a global positioning system sensor, a VHF Omnidirectional Range sensor, Instrument Landing System (ILS), and the like.

The components of rotorcraft <NUM> (e.g., rotorcraft computers <NUM>, flight control devices <NUM>, etc.) are powered by a battery <NUM>. Battery <NUM> may be a rechargeable battery, such as a lithium-ion battery, a lead-acid battery, or the like. Battery <NUM> may be charged onboard rotorcraft <NUM> (e.g., by an alternator <NUM>), or may be charged by an external battery charger that is not part of rotorcraft <NUM>. In some embodiments, battery <NUM> is part of (e.g., disposed/installed in) a propulsion unit of rotorcraft <NUM> (e.g., an engine <NUM>, see <FIG>). In another embodiment, battery <NUM> is part of other components of rotorcraft <NUM>.

Charging of battery <NUM> may be controlled by a battery management system (BMS). For example, battery <NUM> may include a charging circuit that is controlled by the BMS. Parameters of battery <NUM> may also be monitored by the BMS. For example, battery <NUM> may include sensors for monitoring the discharge rate, cell voltages, temperature, and the like of battery <NUM>, which the BMS receives signals from. The BMS may be partially or wholly embodied as software and/or hardware for performing the desired functionality. For example, the BMS may be embodied as software executed by rotorcraft computers <NUM>, as hardware included with rotorcraft computers <NUM>, as a standalone management circuit/controller, or the like. In the illustrated embodiment, the BMS is embodied as software executed by rotorcraft computers <NUM>.

Battery <NUM> is connected to the components of rotorcraft <NUM> (e.g., flight control devices <NUM>) by power connections <NUM>, and the battery <NUM> is connected to the BMS (e.g., rotorcraft computers <NUM>) by data connections <NUM>. Power connections <NUM> carry the power provided to the components of rotorcraft <NUM>. Data connections <NUM> carry data (e.g., control and/or sensor) signals communicated between the battery <NUM> and rotorcraft computers <NUM>. Data connections <NUM> may be connections for a serial communications protocol, such as I<NUM>C, SPI, RS232, or the like. Power connections <NUM> may be larger (e.g., have a lower gauge) than data connections <NUM>.

In certain embodiments, battery <NUM> is formed in accordance with this disclosure. For example, battery <NUM> may be formed using process <NUM>. In certain embodiments, battery <NUM> could be implemented as battery structure <NUM> or battery structure <NUM>. Implementing battery <NUM> using current collectors formed in accordance with this disclosure may result in battery <NUM> being thinner, lighter, and/or potentially having increased energy density relative to batteries formed using conventional techniques.

Embodiments of this disclosure may provide none, some, or all of the following technical advantages. Furthermore, other advantages may be described in or understood from this disclosure.

A battery current collector according to conventional techniques may be one of the heaviest components in a battery, potentially accounting for <NUM> percent to as much as <NUM> percent of the weight of the battery. Certain embodiments allow formation of battery current collectors that are thinner and possibly lighter relative to current collectors that can be used with conventional techniques. For example, certain embodiments may be used to form current collectors that are about <NUM> to about <NUM>, and about <NUM> or less in particular embodiments. Certain embodiments of this disclosure allow thinner current collectors to be formed and assembled into a battery, while reducing or eliminating concerns with conventional electrode assembly processes that may be encountered with thinly formed current collectors, such as those in which current collectors are pre-formed in sheets that are rolled around a spool and must be robust (e.g., thick) enough to remain undamaged during handling.

Additionally, the conductive material of the current collectors may be a significant contributor to the overall weight of a battery. As made possible by certain embodiments of this disclosure, the ability to form thinner current collectors that include less conductive material and are therefore lighter may reduce the overall weight of a battery formed using such current collectors. A lighter battery generally is preferable because it results in a lighter device (e.g., vehicle, mobile phone, laptop computer, tablet computer, etc.) in which the battery is to be installed. Additionally, lighter batteries may ease recycling challenges, as the vehicles that transport batteries for recycling potentially can carry more batteries at once due to the lighter load per battery.

Furthermore, embodiments of this disclosure allow thinner current collectors to be formed without sacrificing the ability of the resulting current collectors to provide reliable performance in a resulting battery. For example, the processes used to deposit the current collector material are highly precise and controllable to ensure formation of a current collector layer that has adequate coverage and is suitably thick. As another example, forming the current collector layer directly on a previously deposited active material layer (e.g., rather than pre-forming the current collector layer, moving the pre-formed current collector layer around, and then coating the active layer on the current collector layer) may reduce or eliminate opportunities of the current collector to be damaged during the battery assembly process.

In certain embodiments, current collectors of reduced thickness may increase the energy density, the amount of energy a battery can store for a given weight, of lithium ion batteries, which may allow increased time between battery charges, essentially increasing capacity. This feature also may increase the service lifetime of the battery.

Embodiments can be applied to any suitable type of battery form factor, including cylindrical, prismatic, and pouch form factors. Furthermore, electrodes formed according to embodiments of this disclosure can be rolled, stacked, folded, or otherwise assembled into structure to form a battery. In the interest of clarity, all features of an actual implementation may not be described in this specification. It will of course be appreciated that in the development of any such actual embodiment, numerous implementation-specific decisions may be made to achieve the developer's specific goals, such as compliance with system-related and business-related constraints, which will vary from one implementation to another. Moreover, it should be appreciated that such a development effort might be complex and time-consuming but would nevertheless be a routine undertaking for those of ordinary skill in the art having the benefit of this disclosure.

Reference may be made herein to the spatial relationships between various components and to the spatial orientation of various aspects of components as the devices are depicted in the attached drawings. However, as will be recognized by those skilled in the art after a complete reading of the present disclosure, the devices, members, apparatuses, etc. described herein may be positioned in any desired orientation. Thus, the use of terms such as "above," "below," "upper," "lower," or other like terms to describe a spatial relationship between various components or to describe the spatial orientation of aspects of such components should be understood to describe a relative relationship between the components or a spatial orientation of aspects of such components, respectively, as the device described herein may be oriented in any desired direction.

Claim 1:
A method, comprising:
providing a first substrate; and
forming a first battery electrode on the first substrate, wherein forming the first battery electrode on the first substrate comprises:
depositing a first layer of a first electrode active material on a first portion of a surface of the first substrate; and
forming a first current collector that comprises a first conductive material, wherein forming the first current collector comprises depositing, using a thin film deposition process, the first conductive material on a surface of the first layer of the first electrode active material, the first conductive material being deposited over an edge of the first layer of the first electrode active material and onto a second portion of the surface of the first substrate, the second portion of the first substrate being adjacent to the first portion of the first substrate; and
removing the first battery electrode from the first substrate, the first battery electrode comprising the first layer of the first electrode active material and the first current collector.