BATTERY WITH BLENDED BATTERY CELLS

A battery includes S battery cells of a first type. Each of the S battery cells includes a plurality of first cathode electrodes and a plurality of first anode electrodes. The battery includes T battery cells of a second type, wherein each of the T battery cells includes a plurality of second cathode electrodes and a plurality of second anode electrodes, where S and T are integers greater than one. The T battery cells are arranged between the S battery cells. At least one of the plurality of first cathode electrodes includes a first cathode active material that is different than a second cathode active material of the plurality of second cathode electrodes. The plurality of first anode electrodes includes a first anode active material that is different than a second anode active material of the plurality of second anode electrodes.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of Chinese Patent Application No. 202211127786.4, filed on Sep. 16, 2022. The entire disclosure of the application referenced above is incorporated herein by reference.

INTRODUCTION

The present disclosure relates to batteries, and more particularly to batteries including different types of battery cells.

Electric vehicles (EVs) such as battery electric vehicles (BEVs), hybrid vehicles, and/or fuel cell vehicles include one or more electric machines and a battery system including one or more battery cells, modules and/or packs. A power control system is used to control power to/from the battery system during charging, propulsion and/or regeneration. When one of the battery cells of the battery system fails, the battery cells may be damaged and/or thermal runaway may occur. Thermal runaway of one battery cell may cause propagation to other battery cells.

SUMMARY

A battery includes S battery cells of a first type. Each of the S battery cells includes a plurality of first cathode electrodes and a plurality of first anode electrodes. The battery includes T battery cells of a second type, wherein each of the T battery cells includes a plurality of second cathode electrodes and a plurality of second anode electrodes, where S and T are integers greater than one. The T battery cells are arranged between the S battery cells. At least one of the plurality of first cathode electrodes includes a first cathode active material that is different than a second cathode active material of the plurality of second cathode electrodes. The plurality of first anode electrodes includes a first anode active material that is different than a second anode active material of the plurality of second anode electrodes.

In other features, S is greater than T and T is equal to S−1. The S battery cells of the first type and the T battery cells of the second type are arranged in repeating connection segments. For each of the repeating connection segments, corresponding ones of the S battery cells of the first type are connected in series and corresponding ones of the T battery cells of the second type are connected in parallel between the S battery cells.

In other features, the first cathode active material is selected from a group consisting of lithium cobalt oxide (LCO), lithium nickel cobalt manganese (NCM), lithium nickel cobalt aluminum (NCA), nickel cobalt manganese aluminum (NCMA), lithium manganese oxide (LMO), and combinations thereof. The second cathode active material is selected from a group consisting of lithium iron phosphate (LFP), lithium manganese iron phosphate (LMFP), lithium metal polymer (LMP), and combinations thereof.

In other features, the first anode active material is selected from a group consisting of graphite, silicon (Si), and combinations thereof. The second anode active material is selected from a group consisting of lithium titanium oxide (LTO), niobium titanium oxide (NbTiOx), and combinations thereof.

In other features, the first cathode active material has an onset temperature that is less than or equal to 200° C., and the second cathode active material has an onset temperature that is greater than or equal to 250° C.

In other features, the first anode active material has an onset temperature that is less than or equal to 150° C., and the second anode active material has an onset temperature that is greater than or equal to 180° C.

In other features, the S battery cells of the first type are connected in series and the T battery cells of the second type are connected in series.

In other features, a first voltage sensor configured to sense a first voltage of the S battery cells of the first type. A second voltage sensor is configured to sense a second voltage of the T battery cells of the second type. A DC-DC converter is configured to boost the second voltage to the first voltage.

In other features, a controller configured to calculate a first state of charge of the S battery cells of the first type and calculate a second state of charge of the T battery cells of the second type. The controller calculates the first state of charge in a manner that is different than the second state of charge.

In other features, a controller configured to calculate a first state of health of the S battery cells of the first type. The controller calculates a second state of health of the T battery cells of the second type. The controller calculates the first state of health in a manner that is different than the second state of health.

In other features, a polarity of external tabs of at least one of the S battery cells of the first type is inverted relative to others of the S battery cells of the first type. A first thickness of the S battery cells of the first type is different than a second thickness of the T battery cells of the second type.

A battery includes S battery cells of a first type. Each of the S battery cells includes a plurality of first cathode electrodes and a plurality of first anode electrodes. The battery includes T battery cells of a second type. Each of the T battery cells includes a plurality of second cathode electrodes and a plurality of second anode electrodes, where S and T are greater than one. The T battery cells are arranged between the S battery cells. At least one of the plurality of first cathode electrodes includes a first cathode active material that is different than a second cathode active material of the plurality of second cathode electrodes, and the plurality of first anode electrodes includes a first anode active material that is different than a second anode active material of the plurality of second anode electrodes. The first cathode active material has an onset temperature that is less than or equal to 200° C. The second cathode active material has an onset temperature that is greater than or equal to 250° C. The first anode active material has an onset temperature that is less than or equal to 150° C. The second anode active material has an onset temperature that is greater than or equal to 180° C.

In other features, the first cathode active material is selected from a group consisting of lithium cobalt oxide (LCO), lithium nickel cobalt manganese (NCM), lithium nickel cobalt aluminum (NCA), nickel cobalt manganese aluminum (NCMA), lithium manganese oxide (LMO), and combinations thereof. The second cathode active material is selected from a group consisting of lithium iron phosphate (LFP), lithium manganese iron phosphate (LMFP), lithium metal polymer (LMP), and combinations thereof.

In other features, the first anode active material is selected from a group consisting of graphite, silicon (Si), and combinations thereof. The second anode active material is selected from a group consisting of lithium titanium oxide (LTO), niobium titanium oxide (NbTiOx), and combinations thereof. A first thickness of the S battery cells of the first type is different than a second thickness of the T battery cells of the second type. A polarity of external tabs of at least one of the S battery cells of the first type is inverted relative to others of the S battery cells of the first type.

DETAILED DESCRIPTION

While the batteries and/or battery cells are described below in the context of vehicles, the batteries and/or battery cells can be used in non-vehicle applications.

A battery according to the present disclosure includes a blend of a first type of battery cells and a second type of battery cells. In some examples, the blend has a 1:1 ratio. In other examples the blend has a S:T ratio (of the first type/second type), where S and T are integers. The first type of battery cells has a higher power density and/or a lower onset temperature for thermal runaway than the second type of battery cells.

The second type of battery cells are arranged between one or more of the first type of battery cells to reduce thermal runaway propagation. In some examples, the second type of battery cells are thinner and have a lower capacity. In some examples, the second type of battery cells are connected in parallel as a group and then serially connected between the first type of battery cells. This type of connection balances volumetric/mass energy density of the battery module/pack.

In other examples, the first type of battery cells is connected in series, the second type of battery cells are connected in series, and a DC/DC converter is used to equalize voltage outputs of the second type of battery cells relative to the first type of battery cells. In some examples, a controller is configured to calculate state of charge (SOC) and/or state of health (SOH) of the first type of battery cells in a manner that is different than the second type of battery cells.

Referring now toFIG.1, an example of a battery20including serial connected battery cells22-1,22-2, . . . , and22-N (where N is an integer greater than one) is shown. The battery cells22-1,22-2, . . . , and22-N are made using the first type of battery cells. When one of the battery cells fails, the temperature of the battery cell increases, and thermal runaway of the battery cell can occur. Heat from the failed battery cell may propagate to other battery cells and cause thermal runaway propagation.

Referring now toFIG.2, an example of a battery40including the first type of battery cells and a second type of battery cells that are interleaved and connected together is shown. The battery40includes battery cells42-1,42-2, . . . , and42-P of a first type (collectively or individually first type of battery cells42) (where P is an integer greater than one). The battery40further includes battery cells44-1,44-2, . . . , and44-Q of a second type (collectively or individually second type of battery cells44) (where Q is an integer greater than one). The first type of battery cells42and the second type of battery cells44include external tabs43.

In some examples, the first type of battery cells42have a higher power density and/or a lower onset temperature than the second type of battery cells42. In other words, the second type of battery cells42are less likely to encounter thermal runaway than the first type of battery cells42.

In some examples, the first type of battery cells42are made using different anode and/or cathode active materials than the second type of battery cells42. In some examples, the first type of battery cell includes cathode active material selected from a group consisting of lithium cobalt oxide (LCO), lithium nickel cobalt manganese (NCM), lithium nickel cobalt aluminum (NCA), nickel cobalt manganese aluminum (NCMA), lithium manganese oxide (LMO), and combinations thereof. In some examples, the first type of battery cells includes cathode active material selected from a group consisting of NCM/NCMA or other high Ni-ternary cathode-based cells. In some examples, the first type of battery cell includes anode active material selected from a group consisting of graphite and silicon (Si).

In some examples, the second type of battery cell include cathode active material selected from a group consisting of lithium iron phosphate (LFP), lithium manganese iron phosphate (LMFP), lithium metal polymer (LMP) (olivine type cathode), and combinations thereof. In some examples, the second type of battery cell include cathode active material selected from a group consisting of LFP/lithium titanium oxide (LTO), and LMFP/LTO. In some examples, the second type of battery cell include anode active material selected from a group consisting of LTO and niobium titanium oxide (NbTiOx).

In some examples, the first type of battery cells includes a cathode active material having an onset temperature less than or equal to 200° C. and the second type of battery cells include a cathode active material having an onset temperature that is greater than or equal to 250° C. In some examples, the first type of battery cells includes an anode active material having an onset temperature less than or equal to 150° C. and the second type of battery cells include an anode active material having an onset temperature that is greater than or equal to 180° C. In some examples, the second type of battery cells include an anode active material having an onset temperature that is greater than or equal to 200° C.

In this example, the first type of battery cells42and the second type of battery cells44alternate and are connected together. When one of the first type of battery cells42fails and encounters thermal runaway conditions, the second type of battery cells44provide a thermal block that reduces the likelihood of thermal runaway propagation. One issue with this arrangement is that the thickness of the second type of battery cells44would need to be increased if connected in series with the first type of battery cells to handle the current and/or voltage demands of the first type of battery cells42during charging and/or discharging. Therefore, some of the examples below include a combination of parallel and series connections.

Referring now toFIG.3, a battery100includes a first type of battery cells and a second type of battery cells that are interleaved and connected together. The battery100includes battery cells110-1,110-2, . . . , and110-B of a first type (collectively or individually first type of battery cells110) (where B is an integer greater than one). The battery100further includes battery cells116-1,116-2, . . . , and116-S of a second type (collectively or individually second type of battery cells116) (where S is an integer greater than one). In this example, S=B−1.

The first type of battery cells110and the second type of battery cells116include external tabs114(corresponding to positive and negative terminals) located on top and bottom sides thereof. As can be appreciated, the positive and negative terminals can be located on adjacent sides, opposite sides, or on the same side. In addition, the location of the positive or negative terminals may be aligned from one battery cell to the next adjacent battery cell or may vary from one battery cell to the next adjacent battery cell.

In some examples, the first type of battery cells110have a higher power density and/or a lower onset temperature than the second type of battery cells116. In other words, the second type of battery cells116are less likely to encounter thermal runaway than the first type of battery cells110. In some examples, the first type of battery cells110are made using different anode and/or cathode materials than the second type of battery cells116. In some examples, the thickness of the first type of battery cells110is greater than the thickness of the second type of battery cells116.

Referring now toFIG.4, an example of a connection arrangement150between the first type of battery cells110and the second type of battery cells116is shown. The connection arrangement150includes repeating segments154-1,154-2, . . . , and154-T, (where T is an integer greater than one) having similar connections. InFIG.4, the first type of battery cells110are labelled N1, N2, and N3for each of the repeating segments and the second type of battery cells116are labelled S1, S2and S3for each of the repeating segments.

In the repeating segment154-1, a negative terminal of a battery cell N1is connected to positive terminals of battery cell S1, S2and S3. A negative terminal of the battery cell S1is connected to a positive terminal of the battery cell N2and negative terminals of the battery cells S2and S3. A negative terminal of the battery cell N2is connected to a positive terminal of the battery cell N3. A negative terminal of the battery cell N3is connected a positive terminal of the battery cell N1of the repeating segment154-2and so on.

A positive terminal of the battery150is connected to a positive terminal of the battery cell N1of the repeating segment154-1. A negative terminal of the battery is connected to a negative terminal of the battery cell N3of the repeating segment154-T.

The battery inFIG.4is characterized as follows:

More generally, for an arrangement including n of the first type of battery cells and m of the second type of battery cells and every c ones of the second type of battery cells are connected in parallel: Vcell N1*n+Vcell S1*m/c=Vmodule.

Referring now toFIG.5, another example of connections between the first type of battery cells and the second type of battery cells is shown. A battery200includes battery cells210-1,210-2,210-3, and210-4of the first type (collectively first type of battery cells210) and battery cells214-1,214-2, and214-3of the second type (collectively second type of battery cells214). The first type of battery cells210and the second type of battery cells214include a positive terminal212and a negative terminal213.

In this example, the first type of battery cells210and the second type of battery cells214are arranged as follows:210-1,214-1,210-2,214-2,210-3,214-3, and210-4. Polarities of the first type of battery cells210and the second type of battery cells214at one side (e.g., the top side) of the battery200are −, +, −, +, +, +, and −. As can be seen, the polarity of at least one of the first type of battery cells (e.g.,210-3) is inverted relative to others of the P battery cells of the first type. Terminals of the battery cells210-1,214-1,214-2, and214-3on the one side are shorted. Terminals of the battery cells210-2and210-4on the one side are shorted.

Polarities of the first type of battery cells210and the second type of battery cells214at the opposite side (e.g., the bottom side) of the battery200are +, −, +, −, −, −, and +. Terminals of the battery cells214-1,210-2,214-2, and214-3on the opposite side are shorted. Terminals of the battery cells210-3and210-4on the opposite side are shorted.

The above description relates to serially connected battery cells210. In some examples, the battery cells210are connected in parallel to some of its neighbors and then serially connected, to form an nSmP connection. In this case, the battery cells210connected in parallel have the same tab polarity orientation and have their positive terminal shorted, negative terminal shorted as well. Other connections are the same as those shown inFIG.5.

Referring now toFIG.6, another example of connections between the first type of battery cells and the second type of battery cells is shown. A battery240includes battery cells250-1,250-2,250-3, and250-4(collectively first type of battery cells250) of the first side and battery cells254-1,254-2, and254-3of the second type (collectively second type of battery cells254). The first type of battery cells250and the second type of battery cells254include first terminals252and second terminals253located on the same side surface of the battery cells.

In this example, the first type of battery cells250and the second type of battery cells254are arranged as follows:250-1,254-1,250-2,254-2,250-3,254-3, and250-4. Polarities of the battery cells at the second terminals253of the battery200are −, +, +, +, −, +, and −, respectively. The second terminals253of the battery cells254-1,254-2,254-3, and250-4are shorted. The second terminals253of the battery cells250-2and250-3are shorted.

Polarities of the battery cells at the first terminals252of the battery200are +, −, +, −, −, −, and +. The first terminals252of the battery cells254-1,250-2,254-2, and254-3are shorted. The first terminals252of the battery cells250-3and250-4are shorted.

In the above description, the battery cells250are connected in series. In some examples, the battery cells250are connected in parallel to some of its neighbors and then serially connected, forming an nSmP connection. In this case, the battery cells250parallelly connected250cells has the same tab polarity orientation and having their positive terminal shorted, negative terminal shorted as well. Other connections are the sane as shown byFIG.6.

While the preceding example included alternating or interleaved battery cells, other patterns can be used. For example, P battery cells of the first type can be arranged side by side and then R battery cells of the second type can be arranged side by side (where P and R are integers). In some examples, P>1 and R=1, although other values can be used.

Referring now toFIG.7, another example of a battery300including a first type of battery cells and a second type of battery cells that are interleaved and connected together is shown. The battery300includes battery cells310-1,310-2, . . . ,310-P,310-(P+1),310-(P+2),310-(2P) . . . of a first type (collectively or individually first type of battery cells310) (where P is an integer greater than one). The battery300further includes battery cells314-1,314-2, . . . of a second type (collectively or individually second type of battery cells314). The first type of battery cells310and the second type of battery cells314include external tabs located on top and bottom sides thereof as will be described below.

Referring now toFIG.8, an example of a connection arrangement330between the battery cells310and314is shown. The connection arrangement330includes repeating segments332-1,332-2, . . . , and332-T, (where T is an integer greater than one) having similar connections. InFIG.8, the battery cells310are labelled N1, N2, and NP for each of the repeating segments and the battery cells are labelled S1for each of the repeating segments.

A negative terminal of a battery cell N1of the repeating segment332-1is connected to negative terminals of the battery cells N2, . . . , and NP of the repeating segment332-1and to a positive terminal of a battery cell S1of the repeating segment332-1. A positive terminal of the battery cell N1of the repeating segment332-1is connected to positive terminals of the battery cells N2, . . . , and NP of the repeating segment332-1.

The negative terminal of the battery cell S1of the repeating segment332-1is connected to the positive terminal of the battery cell N1of the repeating segment332-2. The positive terminal of the battery cell S1of the repeating segment332-1is connected to the positive terminals of the battery cells S1of the remaining repeating segments332-2,332-3, . . . . The negative terminals of the battery cells N1, N2, . . . , and NP of the repeating segment332-2are connected to the negative terminals of the battery cells N1, N2, . . . , and NP of the repeating segment332-3. Additional repeating segments are connected in a similar way.

The positive terminal of the battery330is connected to the positive terminal of the battery cell N1of the repeating segment332-1. The negative terminal of the battery330is connected to the negative terminal of the battery cell S1of a last one of the repeating segments (e.g., S1of the repeating segment332-3in this example).

In some examples, cathodes of the first type of battery cell have loading of 5 mAh/cm2, active material including NCMA, a specific capacity of 200 mAh/g, and a density of 3.3 g/cc. In some examples, anodes of the first type of battery cell have loading of 5.5 mAh/cm2, active material including graphite/silicon oxide (Gr/SiOx), a specific capacity of 500 mAh/g, and a density of 1.5 g/cc.

In some examples, cathodes of the second type of battery cell have loading of 5 mAh/cm2, active material including LMFP, a specific capacity of 150 mAh/g, and a density of 2.0 g/cc. In some examples, anodes of the second type of battery cell have loading of 5.5 mAh/cm2, active material including LTO, a specific capacity of 160 mAh/g, and a density 2.4 g/cc. In some examples, the separators have a thickness of 10 um. In some examples, the current collectors include aluminum foil having a thickness of 10 um or copper foil having a thickness of 8 um.

In this example, the volumetric energy density ratio of the first type of battery cell divided by the second type of battery cell is approximately 2. Assuming the same cell length/width, a thickness ratio of first type/second type is ˜0.5.

In a module with 20 total cells, 4 of the first type of battery cells are replaced by 8 of the second type of battery cells (20% volume). The thickness of second type of battery cells is half of the first type of battery cell. Every 2 of the second type of battery cells are connected in parallel before being serially connected to the first type of battery cells. This arrangement provides a significant reduction in the likelihood of thermal runaway propagation with about 10% volumetric energy density loss.

In some examples, cathodes of the first type of battery cell have loading of 5 mAh/cm2, active material including NCMA, a specific capacity of 200 mAh/g, and a density of 3.3 g/cc. In some examples, anodes of the first type of battery cell have loading of 5.5 mAh/cm2, active material including Gr/SiOx, a specific capacity of 500 mAh/g, and a density of 1.5 g/cc.

In some examples, cathodes of the second type of battery cell have loading of 5 mAh/cm2, active material including LMFP, a specific capacity of 150 mAh/g, and a density of 2.0 g/cc. In some examples, anodes of the second type of battery cell have loading of 5.5 mAh/cm2, active material including LTO, a specific capacity of 160 mAh/g, and a density 2.4 g/cc. In some examples, the separators have a thickness of 10 um. In some examples, the current collectors include aluminum foil having a thickness of 10 um or copper foil having a thickness of 8 um. In this example, the volumetric energy density ratio of the first type of battery cell divided by the second type of battery cell is approximately 2. Assuming the same cell length/width, a thickness ratio of first type/second type is ˜0.5.

In a module with 20 total cells, 2 of the first type of battery cells are replaced by 8 of the second type of battery cells (10% volume). The thickness of second type of battery cells is one quarter of the first type of battery cell. Every 4 of the second type of battery cells are connected in parallel before being serially connected to the first type of battery cells. This arrangement provides a significant reduction in the likelihood of thermal runaway propagation with about 5% volumetric energy density loss.

Referring now toFIG.9, a battery400including the first type of battery cells and the second type of battery cells and a DC/DC converter is shown. The battery400includes battery cells410-1,410-2,410-3,410-4, and410-5of a first type (collectively or individually first type of battery cells410).

The battery400further includes battery cells414-1,414-2,414-3,414-4, and414-5of a second type (collectively or individually second type of battery cells414). The battery cells410and414include positive and negative terminals416and418located on top and bottom sides thereof as will be described below. As can be appreciated, the positive and negative terminals can be located on adjacent sides or the same side.

In this example, the first type of battery cells410-1,410-2,410-3,410-4, and410-5are connected in series and the second type of battery cells414-1,414-2,414-3,414-4, and414-5are connected in series. Positive and negative terminals of the battery cells414are connected to an input of the voltage sensor440and an input of a DC/DC converter444. Positive and negative terminals of the battery cells414are connected to an input of the voltage sensor446. The voltage sensors440and446sense voltage outputs of the second type of battery cells414and the first type of battery cells410, respectively.

In some examples, the DC/DC converter444adjusts the voltage output of the second type of battery cells414to the output voltage of the first type of battery cells410. In some examples, the output of the battery cells414is boosted. An output of the DC/DC converter444is connected to the output of the first type of battery cells410.

Referring now toFIG.10, a battery system460further includes a current sensor470sensing current from the second type of battery cells and a current sensor474sensing current from the first type of battery cells. Outputs of the current sensors470and474, the voltage sensors440and446, and/or other sensed or calculated parameters are input to a controller480. The controller480includes a first module484configured to calculate at least one of state of charge (SOC1) or state of health (SOH1) of the first type of battery cells and a second module configured to calculate at least one of state of charge (SOC2) or state of health (SOH2) of the first type of battery cells.

In some examples, the SOC and/or SOH algorithm calculating SOC1and/or SOH1for the first type of battery cell is the same as the SOC and/or SOH algorithm calculating SOC2and/or SOH2for the second type of battery cells. The first type of battery cells has different chemistry and different response while working as compared to the second type of battery cells. In some examples, the SOC and/or SOH algorithm calculating SOC1and/or SOH1for the first type of battery cell is different than the SOC and/or SOH algorithm calculating SOC2and/or SOH2for the second type of battery cells.

In some examples, SOC detection parameters (resistance/capacitance (R/C) in RC model, open circuit voltage (OCV), Kalman filter (KF) matrices, etc.) are different and the SOC is calculated independently for the first type of battery cells and the second type of battery cells. In some examples, SOH detection parameters (decaying slope, activation energy/pre-exponential factor (Ea/A) in Arrhenius decaying) are different, and the SOC is calculated independently for the first type of battery cells and the second type of battery cells.