Patent Description:
When a battery (electrochemical device) is in use, thermal runaway may occur and result in an increase in the internal pressure in a housing of the battery, thereby causing the battery housing to expand and even causing problems such as battery explosion. To alleviate the increase in the internal pressure of the battery, a conventional method is to create a pressure relief groove or a pressure relief hole on the battery housing by laser drilling, and dispose a pressure relief valve at the pressure relief groove or pressure relief hole. The laser drilling operation is cumbersome, and impairs production efficiency of the battery. In addition, due to the existence of the pressure relief valve, the material cost is increased, and a relatively large workspace needs to be reserved for opening the valve, thereby impairing the energy density of the battery.

Documents <CIT> and <CIT> are disclosing electrochemical devices comprising an insulating member.

An objective of this application is to provide an electrochemical device and an electronic device to at least improve the production efficiency and energy density of the electrochemical device.

According to a first aspect of this application, an electrochemical device is provided, including a housing, an insulation assembly, and an electrode post. The housing defines an accommodation cavity and includes a first sidewall. The first sidewall includes a first wall face oriented toward the accommodation cavity and a second wall face oriented away from the accommodation cavity. The first sidewall includes a mounting hole that runs through the first wall face and the second wall face. The insulation assembly is snugly connected to the first wall face or the second wall face. The insulation assembly includes a first insulator. The first insulator includes a penetrative first through-hole. The first through-hole communicates with the mounting hole. The electrode post includes a first part and a second part. The first part is snugly connected to an end face of the insulation assembly, and the end face is oriented away from the first sidewall. The first part covers the first through-hole. The second part is disposed in the mounting hole and the first through-hole. One end of the second part is connected to an end face of the first part, and the end face is oriented toward the first sidewall.

The first insulator is able to be melted when a temperature in the accommodation cavity rises to a first threshold, and generate, under an action of a gas pressure in the accommodation cavity, a pressure relief channel that communicates the accommodation cavity to an outside of the housing.

In an embodiment of this application, the first insulator can be activated by a high temperature, so that the first insulator can bond the electrode post to the housing. The hermetic insulation function can be implemented under normal working conditions (that is, when the electrochemical device works normally). When the electrochemical device is thermally runaway, that is, when a temperature in an accommodation cavity rises to a first threshold, the gas in the accommodation cavity thermally expands, the first insulator is melted and generates, under an action of a gas pressure in the accommodation cavity, a pressure relief channel that communicates the accommodation cavity to the outside of the housing, so as to reduce the gas pressure in the accommodation cavity, and effectively prevent explosion of the electrochemical device caused by thermal runaway. In contrast to the conventional pressure relief groove or pressure relief hole structure, in this embodiment of this application, no additional operations such as laser drilling are required, and the manufacturing process is a simple and improves production efficiency of the electrochemical device. In addition, the insulation assembly serves functions of both insulation and pressure relief and avoids use of the components such as the pressure relief valve, thereby not only reducing the material cost, but also improving the energy density of the electrochemical device.

The insulation assembly further includes a second insulator. In a thickness direction of the first sidewall, the first insulator and the second insulator are stacked together. The second insulator includes a penetrative second through-hole. The second through-hole communicates with the first through-hole and the mounting hole. A melting point of the second insulator is higher than a first threshold.

When the temperature of the accommodation cavity rises to the first threshold, the first insulator melts while the second insulator remains in a solid form and is bonded to the housing or the electrode post. In addition, the second insulator is still bonded to the hot-melted first insulator to increase the overall strength of the insulation assembly, thereby improving the stability of bonding between the housing and the electrode post, and reducing overflow of the hot-melted first insulator.

According to some embodiments of this application, the insulation assembly further includes a third insulator. In the thickness direction of the first sidewall, the first insulator, the second insulator, and the third insulator are stacked together. The second insulator is disposed between the first insulator and the third insulator. The third insulator includes a penetrative third through-hole. The third through-hole communicates with the first through-hole, the second through-hole, and the mounting hole. A melting point of the third insulator is lower than the melting point of the second insulator.

Further, the melting points of the first insulator and the third insulator are <NUM> to <NUM>, and the melting point of the second insulator is <NUM> to <NUM>.

When the temperature of the accommodation cavity rises to the first threshold (<NUM> to <NUM>), the first insulator and the third insulator melt to create a pressure relief channel to quickly expel the gas while the second insulator is still in a solid state. The second insulator is bonded between the hot-melted first and third insulators to improve the overall strength of the insulation assembly and reduce the overflow of the hot-melted first and third insulators.

According to some embodiments of this application, the electrochemical device further includes a connecting plate. The insulation assembly is connected to the first wall face or the second wall face of the housing through the connecting plate. The connecting plate includes a fourth through-hole. The fourth through-hole communicates with the mounting hole and the first through-hole.

The electrode post, the insulation assembly, and the connecting plate can be snugly connected outside the accommodation cavity (the electrode post, the insulation assembly, and the connecting plate form an electrode post insulation structure). The connection implemented by the connecting plate can easily improve the mounting precision of the insulation assembly and the electrode post on the housing. In addition, the connection between the electrode post insulation structure and the housing can be implemented separately. The electrode post insulation structure is also applicable to the housings of other electrochemical devices, thereby implementing the standardization and universal applicability of the electrode post insulation structure.

According to some embodiments of this application, the insulation assembly is bonded between the first part and the connecting plate by hot pressing. The hot-pressing bonding operation is convenient and fast, and improves the mounting efficiency.

According to some embodiments of this application, the insulation assembly is snugly connected to the first wall face. The second part includes a protruding portion oriented away from the first part. The protruding portion protrudes from the mounting hole. The protruding portion is located on a side of the first sidewall, and the side is oriented away from the accommodation cavity. The second part protrudes from the mounting hole, thereby facilitating conduction with an external circuit.

According to some embodiments of this application, the protruding portion is bent toward a direction parallel to the second wall face. By bending the protruding portion, the connection area between the second part and the external circuit is increased, and the stability of the connection between the external circuit and the second part is improved.

According to some embodiments of this application, viewed along a direction perpendicular to the first sidewall, the second part is located in a region of the first through-hole and the mounting hole. A first annular clearance exists between the second part and a wall of the mounting hole. A second annular clearance exists between the second part and a wall of the first through-hole. Both the first annular clearance and the second annular clearance are disposed around the second part. By disposing the first annular clearance and the second annular clearance, the gas can be expelled out of the housing through the first annular clearance and the second annular clearance when the electrochemical device is thermally runaway.

According to some embodiments of this application, the insulation assembly is snugly connected to the first wall face, a first blind hole is created on an end face of the second part, the end face is oriented away from the first part, and the first blind hole extends toward the first part. By disposing the first blind hole, it is convenient to connect an external circuit to the electrode post.

Alternatively, the insulation assembly is snugly connected to the second wall face, a second blind hole is created on an end face of the first part, the end face is oriented away from the second part, and the second blind hole extends toward the second part. By disposing the second blind hole, it is convenient to connect an external circuit to the electrode post.

According to some embodiments of this application, along a direction from the insulation assembly to the first sidewall, a thickness of the second insulator is <NUM>% to <NUM>% of a thickness of the first insulator, and the thickness of the second insulator is <NUM>% to <NUM>% of a thickness of the third insulator.

When the thickness of the second insulator is relatively large, the overall strength of the insulation assembly is higher. When the thicknesses of the first insulator and the third insulator are relatively large, it is easier to form a pressure relief channel to facilitate the expulsion of gas.

According to some embodiments of this application, the electrochemical device satisfies at least one of the following conditions:.

Further, along the direction from the insulation assembly to the first sidewall, the thickness of the insulation assembly is <NUM> to <NUM>; along the direction from the insulation assembly to the first sidewall, the thickness of the first part is <NUM> to <NUM>, and the thickness of the second part is <NUM> to <NUM>; and, along a thickness direction of the first sidewall in the insulation assembly, the thickness of the first sidewall is <NUM> to <NUM>.

The thicknesses of the insulation assembly, the first part, and the second part are all relatively small, thereby reducing the space occupation, and increasing the energy density of the electrochemical device. The thickness of the first part is set to be greater than that of the second part, and the bonding part is the first part, so as to improve the stability of the bonding between the electrode post and the insulation assembly. The thickness of the electrode post is relatively small, and the insulation assembly falls within the thickness range specified above, so that the insulation assembly is strong enough to bond the electrode post to the first sidewall of the housing.

According to a second aspect, this application further provides an electronic device. The electronic device includes the electrochemical device according to any one of the embodiments of the first aspect.

The foregoing description is merely an overview of the technical solutions of this application. Some specific embodiments of this application are described below illustratively to enable a clearer understanding of the technical solutions of this application, enable implementation of the technical solutions based on the subject-matter hereof, and make the foregoing and other objectives, features, and advantages of this application more evident and comprehensible.

To describe the technical solutions of the embodiments of this application more clearly, the following outlines the drawings used in the embodiments of this application. Evidently, the drawings outlined below are merely a part of embodiments of this application. A person of ordinary skill in the art may derive other drawings from the outlined drawings.

For ease of understanding this application, the following describes this application in more detail with reference to drawings and specific embodiments. It is hereby noted that an element referred to herein as being "fixed to" another element may be directly disposed on the other element, or may be fixed to the other element with one or more elements in between. An element referred to herein as "connected to" another element may be connected to the other element directly or with one or more elements in between. Unless otherwise defined, all technical and scientific terms used herein bear the same meanings as what is normally understood by a person skilled in the technical field of this application. The terms used in the specification of this application are merely intended to describe specific embodiments but not to limit this application.

In addition, to the extent that no mutual conflict occurs, the technical features described below in different embodiments of this application may be combined with each other.

In this specification, the meanings of "disposing" or "mounting" include fixing or confining an element or unit to a specific position or place by welding/soldering, screwing, snap-fit connection, bonding, or other means, where the element or unit may be held stationary in the specific position or place or may move within a limited range, and the element or unit may be detachable or undetachable after being fixed or confined to the specific position or place, without being limited in embodiments of this application.

According to a first aspect, an embodiment of this application discloses an electrochemical device <NUM>. Referring to <FIG>, which shows an exploded view of the electrochemical device <NUM>, the electrochemical device <NUM> includes a housing <NUM>, an insulation assembly <NUM>, and an electrode post <NUM>. A mounting hole <NUM> is created on the housing <NUM>. The electrode post <NUM> is disposed at the mounting hole <NUM>. The electrode post <NUM> is configured to implement electrical conduction between the electrochemical device <NUM> and an external circuit. The insulation assembly <NUM> is configured to separate the electrode post <NUM> from the housing <NUM> so that the electrode post <NUM> is insulated from the housing <NUM>. It is hereby noted that, in this embodiment of this application, the electrochemical device <NUM> is a smallest unit that makes up a battery or a battery module, and is a site for conversion between electrical energy and chemical energy.

With respect to the housing <NUM>, referring to <FIG>, the housing <NUM> defines an accommodation cavity <NUM>. The electrochemical device <NUM> further includes an electrode assembly <NUM> and an electrolyte solution (not shown in the drawing). Both the electrode assembly <NUM> and the electrolyte solution may be accommodated in the accommodation cavity <NUM>. The housing <NUM> includes a cover <NUM>. The cover <NUM> fits on the top of the housing <NUM>. After the electrode assembly <NUM> and the electrolyte solution are accommodated in the accommodation cavity <NUM>, the housing <NUM> can be sealed by putting the cover <NUM> on. The housing <NUM> further includes a first sidewall <NUM>. The first sidewall <NUM> is connected to the top cover. The first sidewall <NUM> includes a first wall face <NUM> and a second wall face <NUM>. The first wall face <NUM> is disposed toward the accommodation cavity <NUM>. The second wall face <NUM> is disposed away from the accommodation cavity <NUM>. The mounting hole <NUM> is created on the first sidewall <NUM>. The mounting hole <NUM> runs through the first wall face <NUM> and the second wall face <NUM>.

For the insulation assembly <NUM>, referring to <FIG>, the insulation assembly <NUM> is snugly connected to the first wall face <NUM> or the second wall face <NUM>. The insulation assembly <NUM> is configured to isolate and insulate the electrode post <NUM> from the housing <NUM>. The insulation assembly <NUM> includes a first insulator <NUM>. The first insulator <NUM> may be snugly connected to the first wall face <NUM> or the second wall face <NUM>. <FIG> shows a structure in which the first insulator <NUM> is connected to the first wall face <NUM>, and <FIG> shows a structure in which the first insulator <NUM> is connected to the second wall face <NUM>. A penetrative first through-hole <NUM> is created on the first insulator <NUM>. The first through-hole <NUM> communicates with the mounting hole <NUM>.

For the electrode post <NUM>, in some embodiments, the housing <NUM> may be a metal housing <NUM>. The metal housing <NUM> is electrically conductive. Therefore, the metal housing <NUM> may be used as a negative electrode of the electrochemical device <NUM>, and a positive electrode may be dielectrically isolated from the metal housing <NUM> by insulating the electrode post <NUM>. In this embodiment, the electrode post <NUM> is a lead-out piece of the positive electrode of the electrochemical device <NUM>, and may be configured to implement electrical conduction between the positive electrode of the electrochemical device <NUM> and an external circuit. Understandably, in some other embodiments, the electrode post <NUM> may be used as a negative electrode instead, with the housing <NUM> serving as a positive electrode.

Referring to <FIG>, the electrode post <NUM> includes a first part <NUM> and a second part <NUM> connected to each other. The first part <NUM> is snugly connected to an end face of the insulation assembly <NUM>, the end face being away from the first sidewall <NUM>. For example, the insulation assembly <NUM> includes a first insulator <NUM>. The first insulator <NUM> is snugly connected to the first wall face <NUM>, and the first part <NUM> of the electrode post <NUM> is snugly connected to the first insulator <NUM> in the accommodation cavity <NUM>; or, the first insulator <NUM> is snugly connected to the second wall face <NUM>, and the first part <NUM> of the electrode post <NUM> is snugly connected to the first insulator <NUM> outside the housing <NUM>. The first part <NUM> covers the first through-hole <NUM> of the first insulator <NUM>. One end of the second part <NUM> is connected to an end face of the first part <NUM>, the end face being oriented toward the first sidewall <NUM>. The other end of the second part <NUM> extends into the first through-hole <NUM> and the mounting hole <NUM>.

Referring to <FIG>, the insulation assembly <NUM> further includes a second insulator <NUM>. In a thickness direction of the first sidewall <NUM> (that is, in a direction from the first wall face <NUM> to the second wall face <NUM>, or in a direction from the second wall face <NUM> to the first wall face <NUM>), the first insulator <NUM> and the second insulator <NUM> are stacked together. A penetrative second through-hole <NUM> is created on the second insulator <NUM>. The second through-hole <NUM> communicates with the first through-hole <NUM> and the mounting hole <NUM>.

The first insulator <NUM> is snugly connected to the first wall face <NUM> or the second wall face <NUM>. <FIG> shows a structure in which the first insulator <NUM> is snugly connected to the first wall face <NUM>, and <FIG> shows a structure in which the first insulator <NUM> is snugly connected to the second wall face <NUM>. The first part <NUM> of the electrode post <NUM> is snugly connected to the second insulator <NUM>. Alternatively, the second insulator <NUM> is snugly connected to the first wall face <NUM> or the second wall face <NUM>, and the first part <NUM> of the electrode post <NUM> is snugly connected to the first insulator <NUM>. The second part <NUM> of the electrode post <NUM> extends into the first through-hole <NUM>, the second through-hole <NUM>, and the mounting hole <NUM>. To facilitate the expulsion of gas, the wall of the first through-hole <NUM> and the wall of the second through-hole <NUM> is in a clearance from the first part <NUM>. A clearance is necessary between the first part <NUM> and the wall of the mounting hole <NUM> to prevent a short circuit caused by direct contact between the first part <NUM> and the housing <NUM>. In this embodiment, the melting point of the second insulator <NUM> is higher than the first threshold. When the temperature of the accommodation cavity <NUM> rises to the first threshold, the first insulator <NUM> melts, and the gas in the accommodation cavity <NUM> thermally expands. In this way, the gas pressure in the accommodation cavity <NUM> rises. Under the action of the high-pressure gas in the accommodation cavity <NUM>, the melted first insulator <NUM> is burst by the gas to generate a pressure relief channel that communicates the accommodation cavity <NUM> to the outside of the housing <NUM>, so as to reduce the gas pressure in the accommodation cavity <NUM>. At this time, the second insulator <NUM> still remains in a solid form and is bonded to the housing <NUM> or the electrode post <NUM>. In addition, the second insulator <NUM> is still bonded to the hot-melted first insulator <NUM> to increase the overall strength of the insulation assembly <NUM>, thereby improving the stability of bonding between the housing <NUM> and the electrode post <NUM>, and reducing overflow of the hot-melted first insulator <NUM>.

It is hereby noted that, in some embodiments, when the first insulator <NUM> is snugly connected to the first wall face <NUM>, the route of the gas is: flowing from the accommodation cavity <NUM>, passing through the pressure relief channel, and then flowing out from the first through-hole <NUM> and the mounting hole <NUM>. When the first insulator <NUM> is snugly connected to the second wall face <NUM>, the route of the gas is: flowing from the accommodation cavity <NUM>, passing through the mounting hole <NUM> and the first through-hole <NUM>, and then flowing out from the pressure relief channel. When the second insulator <NUM> is snugly connected to the first wall face <NUM>, the route of the gas is: flowing from the accommodation cavity <NUM>, passing through the pressure relief channel, and then flowing out from the first through-hole <NUM>, the second through-hole <NUM>, and the mounting hole <NUM>. When the second insulator <NUM> is snugly connected to the second wall face <NUM>, the route of the gas is: flowing from the accommodation cavity <NUM>, passing through the mounting hole <NUM>, the second through-hole <NUM>, and the first through-hole <NUM>, and then flowing out from the pressure relief channel.

In some embodiments, referring to <FIG>, the insulation assembly <NUM> further includes a third insulator <NUM>. In the thickness direction of the first sidewall <NUM>, the first insulator <NUM>, the second insulator <NUM>, and the third insulator <NUM> are stacked together. In addition, the second insulator <NUM> is disposed between the first insulator <NUM> and the third insulator <NUM>. The third insulator <NUM> includes a penetrative third through-hole <NUM>. The third through-hole <NUM> communicates with the first through-hole <NUM>, the second through-hole <NUM>, and the mounting hole <NUM>. In this embodiment, the melting point of the third insulator <NUM> may be set to be the melting point of the first insulator <NUM>, and the melting point of the second insulator <NUM> may be set to be higher than the melting point of the third insulator <NUM>. Specifically, the melting points of the first insulator <NUM> and the third insulator <NUM> may be set to <NUM> to <NUM>, and the melting point of the second insulator <NUM> may be set to <NUM> to <NUM>. The first insulator <NUM>, the second insulator <NUM>, and the third insulator <NUM> may be made of a material selected from PP, LDPE, HDPE, LLDPE, OPP, PS, PVC, PET, PA, PF, or the like. For example, the first insulator <NUM> and the third insulator <NUM> are made of a low-melting PP (melting at <NUM> to <NUM>), and the second insulator <NUM> is made of a high-melting PP (melting at <NUM> to <NUM>). When the temperature of the accommodation cavity <NUM> rises to the first threshold (<NUM> to <NUM>), the first insulator <NUM> and the third insulator <NUM> melt to create a pressure relief channel to quickly expel the gas while the second insulator <NUM> is still in a solid state. The second insulator <NUM> is bonded between the hot-melted first insulator <NUM> and third insulator <NUM> to improve the overall strength of the insulation assembly <NUM> and reduce the overflow of the hot-melted first insulator <NUM> and third insulator <NUM>.

Optionally, along a direction from the insulation assembly <NUM> to the first sidewall <NUM>, a thickness of the second insulator <NUM> is <NUM>% to <NUM>% of a thickness of the first insulator <NUM>, and the thickness of the second insulator <NUM> is <NUM>% to <NUM>% of a thickness of the third insulator <NUM>. When the thickness of the second insulator <NUM> is relatively large, the overall strength of the insulation assembly <NUM> is higher. When the thicknesses of the first insulator <NUM> and the third insulator <NUM> are relatively large, it is easier to form a pressure relief channel to facilitate the expulsion of gas.

Optionally, along the direction from the insulation assembly <NUM> to the first sidewall <NUM>, the thickness of the insulation assembly <NUM> is <NUM> to <NUM>. Along the direction from the insulation assembly <NUM> to the first sidewall <NUM>, the thickness of the first part <NUM> is <NUM> to <NUM>, and the thickness of the second part <NUM> is <NUM> to <NUM>. Along a thickness direction of the first sidewall <NUM> in the insulation assembly <NUM>, the thickness of the first sidewall <NUM> is <NUM> to <NUM>. Further, the thickness of the insulation assembly <NUM> is preferably <NUM> to <NUM>. The thickness of the first part <NUM> is preferably <NUM> to <NUM>, and the thickness of the second part <NUM> is preferably <NUM> to <NUM>. The thickness of the first sidewall <NUM> is preferably <NUM> to <NUM>. The thicknesses of the insulation assembly <NUM>, the first part <NUM>, and the second part <NUM> are all relatively small, thereby reducing the space occupation, and increasing the energy density of the electrochemical device <NUM>. The thickness of the first part <NUM> is generally set to be greater than that of the second part <NUM> to improve the stability of the bonding between the electrode post <NUM> and the insulation assembly <NUM>. The thickness of the electrode post <NUM> is relatively small, and the insulation assembly <NUM> falls within the thickness range specified above, so that the insulation assembly <NUM> is strong enough to bond the electrode post <NUM> to the first sidewall <NUM> of the housing <NUM>.

In some embodiments, referring to <FIG>, <FIG>, the electrochemical device <NUM> further includes a connecting plate <NUM>. The insulation assembly <NUM> is connected to the first wall face <NUM> or the second wall face <NUM> of the housing <NUM> by the connecting plate <NUM>. <FIG> shows a structure in which the connecting plate <NUM> is connected to the first wall face <NUM>, and <FIG> shows a structure in which connecting plate is connected to the second wall face <NUM>. Specifically, the connecting plate <NUM> includes a first end face (not shown in the drawing) and a second end face (not shown in the drawing) that are disposed opposite to each other. The insulation assembly <NUM> is connected to the first end face. The second end face is connected to the first wall face <NUM> or the second wall face <NUM> of the housing <NUM>. A fourth through-hole <NUM> is created on the connecting plate <NUM>. The fourth through-hole <NUM> communicates with the mounting hole <NUM> and the first through-hole <NUM>. During mounting, the insulation assembly <NUM> is fitted and bonded to the connecting plate <NUM>, and then the first part <NUM> of the electrode post <NUM> is directly snugly connected to a side of the insulation assembly <NUM>, the side being away from the connecting plate <NUM>. Finally, the connecting plate <NUM> is fixed to the first wall face <NUM> or the second wall face <NUM>. The insulation assembly <NUM> may be bonded between the first part <NUM> and the connecting plate <NUM> by hot-pressing. The hot-pressing bonding operation is convenient and fast. During disassembling, the connecting plate <NUM> may be detached from the first sidewall <NUM> so that both the electrode post <NUM> and the insulation assembly <NUM> are detached from the first sidewall <NUM>.

The electrode post <NUM>, the insulation assembly <NUM>, and the connecting plate <NUM> can be snugly connected outside the accommodation cavity <NUM> (the electrode post <NUM>, the insulation assembly <NUM>, and the connecting plate <NUM> form an electrode post insulation structure). The connection implemented by the connecting plate <NUM> can easily improve the mounting precision of the insulation assembly <NUM> and the electrode post <NUM> on the housing <NUM>. In addition, the connection between the electrode post insulation structure and the housing <NUM> can be implemented separately. The electrode post insulation structure is also applicable to the housings <NUM> of other electrochemical devices <NUM>, thereby implementing the standardization and universal applicability of the electrode post <NUM> insulation structure.

The electrode post <NUM> is configured to implement electrical conduction to an external circuit. In order to facilitate the conduction between the electrode post <NUM> and the external circuit, in some embodiments, referring to <FIG>, the insulation assembly <NUM> is snugly connected to the first wall face <NUM>. The second part <NUM> includes a protruding portion <NUM> oriented away from the first part <NUM>. The protruding portion <NUM> protrudes from the mounting hole <NUM>. The protruding portion <NUM> is located on a side of the first sidewall <NUM>, the side being oriented away from the accommodation cavity <NUM>. In other words, the second part <NUM> protrudes from the mounting hole <NUM>, thereby facilitating conduction between the electrode post <NUM> and the external circuit.

Further, in some embodiments, referring to <FIG>, the protruding portion <NUM> is bent toward a direction parallel to the second wall face <NUM>. By bending the protruding portion <NUM>, the connection area between the second part <NUM> and the external circuit is increased, and the stability of the connection between the external circuit and the second part <NUM> is improved.

In some embodiments, referring to <FIG>, viewed along a direction perpendicular to the first sidewall <NUM>, the second part <NUM> is located in a region of the first through-hole <NUM> and the mounting hole <NUM>. A first annular clearance <NUM> exists between the second part <NUM> and a wall of the mounting hole <NUM>. A second annular clearance <NUM> exists between the second part <NUM> and a wall of the first through-hole <NUM>. Both the first annular clearance <NUM> and the second annular clearance <NUM> are disposed around the second part <NUM>. By disposing the first annular clearance <NUM> and the second annular clearance <NUM>, the gas can be expelled out of the housing <NUM> through the first annular clearance <NUM> and the second annular clearance <NUM> when the electrochemical device <NUM> is thermally runaway. In addition, the first annular clearance <NUM> isolates the second part <NUM> from the housing <NUM> to prevent a short circuit caused by direct contact between the second part <NUM> and the housing <NUM>.

In some embodiments, referring to <FIG>, the insulation assembly <NUM> is snugly connected to the first wall face <NUM>. The first part <NUM> is snugly connected to an end face of the insulation assembly <NUM>, the end face being away from the first wall face <NUM>. The second part <NUM> extends out of the housing <NUM>. The second part <NUM> is exposed outside the housing <NUM>. A first blind hole <NUM> is created on an end face of the second part <NUM>, the end face being away from the first part <NUM>. The first blind hole <NUM> extends toward the first part <NUM>. The connection between the external circuit and the electrode post <NUM> is facilitated by the first blind hole <NUM>. Alternatively,
referring to <FIG>, the insulation assembly <NUM> is snugly connected to the second wall face <NUM>. The first part <NUM> is snugly connected to an end face of the insulation assembly <NUM>, the end face being away from the first wall face <NUM>. The first part <NUM> is exposed outside the housing <NUM>. The second part <NUM> extends into the accommodation cavity <NUM> of the housing <NUM>. A second blind hole <NUM> is created on an end face of the first part <NUM>, the end face being away from the second part <NUM>. The second blind hole <NUM> extends toward the second part <NUM>. The connection between the external circuit and the electrode post <NUM> is facilitated by the second blind hole <NUM>.

In an embodiment of this application, the first insulator <NUM> can be activated by a high temperature, so that the first insulator <NUM> can bond the electrode post <NUM> to the housing <NUM>. The hermetic insulation function can be implemented under normal working conditions (that is, when the electrochemical device <NUM> works normally). When the electrochemical device <NUM> is thermally runaway, that is, when a temperature in an accommodation cavity <NUM> rises to a first threshold, the gas in the accommodation cavity <NUM> thermally expands, the first insulator <NUM> is melted and generates, under an action of a gas pressure in the accommodation cavity <NUM>, a pressure relief channel that communicates the accommodation cavity <NUM> to the outside of the housing <NUM>, so as to reduce the gas pressure in the accommodation cavity <NUM>, and effectively prevent explosion of the electrochemical device <NUM> caused by thermal runaway. In contrast to the conventional pressure relief groove or pressure relief hole structure, in this embodiment of this application, no additional operations such as laser drilling are required, and the manufacturing process is a simple and improves production efficiency of the electrochemical device <NUM>. In addition, the insulation assembly <NUM> serves functions of both insulation and pressure relief and avoids use of the components such as the pressure relief valve, thereby not only reducing the material cost, but also improving the energy density of the electrochemical device <NUM>.

An embodiment of this application further discloses an electronic device. The electronic device includes the electrochemical device <NUM> according to any one of the foregoing embodiments. The electronic device is not particularly limited in this application, and may be any electronic device known in the prior art. For example, the electronic device includes, but is not limited to, a Bluetooth headset, a mobile phone, a tablet, a notebook computer, an electric toy, an electric tool, an electric power cart, an electric vehicle, a ship, a spacecraft, and the like. The electric toy may include stationary or mobile electric toys, such as a game console, an electric car toy, an electric ship toy, an electric airplane toy, and the like. The spacecraft may include an airplane, a rocket, a space shuttle, a spaceship, and the like.

Claim 1:
An electrochemical device (<NUM>), the electrochemical device (<NUM>) comprises:
a housing (<NUM>), wherein the housing (<NUM>) defines an accommodation cavity (<NUM>), the housing (<NUM>) comprises a first sidewall (<NUM>), the first sidewall (<NUM>) comprises a first wall face (<NUM>) oriented toward the accommodation cavity (<NUM>) and a second wall face (<NUM>) oriented away from the accommodation cavity (<NUM>), and the first sidewall (<NUM>) comprises a mounting hole (<NUM>), the mounting hole (<NUM>) running through the first wall face (<NUM>) and the second wall face (<NUM>);
an insulation assembly (<NUM>), connected to the first wall face (<NUM>) or the second wall face (<NUM>); the insulation assembly (<NUM>) comprises a first insulator (<NUM>), the first insulator (<NUM>) comprises a penetrative first through-hole (<NUM>), and the first through-hole (<NUM>) communicates with the mounting hole (<NUM>);
an electrode post (<NUM>), comprising a first part (<NUM>) and a second part (<NUM>), the first part (<NUM>) is connected to an end face of the insulation assembly (<NUM>), the end face of the insulation assembly (<NUM>) is oriented away from the first sidewall (<NUM>), the first part (<NUM>) covers the first through-hole (<NUM>), the second part (<NUM>) is disposed in the mounting hole (<NUM>) and the first through-hole (<NUM>), one end of the second part (<NUM>) is connected to an end face of the first part (<NUM>), and the end face of the first part (<NUM>) is oriented toward the first sidewall (<NUM>); and
the first insulator (<NUM>) is configured to be melted when a temperature in the accommodation cavity (<NUM>) rises to a first threshold, and generate, under an action of a gas pressure in the accommodation cavity (<NUM>), a pressure relief channel that communicates the accommodation cavity (<NUM>) to an outside of the housing (<NUM>),
characterized in that the insulation assembly (<NUM>) further comprises a second insulator (<NUM>); in a thickness direction of the first sidewall (<NUM>), the first insulator (<NUM>) and the second insulator (<NUM>) are stacked together; the second insulator (<NUM>) comprises a penetrative second through-hole (<NUM>), the penetrative second through-hole (<NUM>) communicates with the first through-hole (<NUM>) and the mounting hole (<NUM>), and a melting point of the second insulator (<NUM>) is higher than the first threshold.