CN216648531U

CN216648531U - Cylindrical high-power lithium battery structure

Info

Publication number: CN216648531U
Application number: CN202122188537.3U
Authority: CN
Inventors: 袁云泉; 赵美菊; 张朋
Original assignee: Shandong Tianhan New Energy Technology Co ltd
Current assignee: Shandong Tianhan New Energy Technology Co ltd
Priority date: 2022-03-21
Filing date: 2022-03-21
Publication date: 2022-05-31
Anticipated expiration: 2032-03-21

Abstract

The utility model discloses a cylindrical high-power lithium battery structure which comprises a cylindrical steel shell, an explosion-proof cap, a winding core and electrolyte, wherein the top of the steel shell is connected with the explosion-proof cap in a rolling and sealing mode, the winding core and the electrolyte are arranged in the steel shell, the winding core is formed by isolating and winding a positive plate and a negative plate through two diaphragm plates, a positive pole lug of the winding core is connected with the explosion-proof cap, a negative pole lug of the winding core is connected with a bus bar, and the bus bar is connected with the bottom of the steel shell. The cathode of the utility model adopts a multi-lug connection bus bar current guide design, the anode adopts a wide lug structure design, and the stop adhesive tape adopts an expansion adhesive tape for damping, thereby not only obviously reducing the internal resistance of the battery, reducing the temperature rise of high-rate charge and discharge, improving the large-current charge and discharge capacity, but also improving the current density distribution homogenization degree, avoiding the lithium precipitation of the cathode, prolonging the cycle service life of the battery, and simultaneously improving the safety of the battery.

Description

Cylindrical high-power lithium battery structure

Technical Field

The utility model relates to the technical field of lithium ion batteries, in particular to a cylindrical high-power lithium battery for heavy-current discharge of electric vehicles or electric tools and the like.

Background

In recent years, lithium ion batteries are widely used in the fields of portable electronic devices, large-scale energy storage devices, electric vehicles and the like, have high working voltage, high energy density, long cycle life, no memory effect, no pollution and the like, and are excellent secondary energy devices.

With the rapid development of the electric automobile industry, the application of the lithium ion battery in the aspect of power energy storage power supply is increased year by year, so the research of the high-power lithium ion battery also gradually enters the blazing. Some emerging fields put higher requirements on lithium ion batteries, and in order to solve the problems of energy crisis and environmental pollution which puzzle the world, the power lithium ion batteries show a vigorous development trend, and need the lithium ion batteries with larger discharge current and higher power; batteries are also required to be discharged at high rates in some electronic products, power tools, and medical devices. At present, the widely applied high-power lithium battery is a square or soft package battery, but the cylindrical high-power lithium battery is expected to be widely applied in the fields because of larger internal polarization and lower safety compared with a cylindrical steel shell battery in the charging and discharging processes. The conventional cylindrical battery can only lead out the positive electrode and the negative electrode through one tab, if heavy current charging and discharging is carried out, the temperature rise of the battery is high, the service life and the performance of the battery are greatly influenced, the space utilization rate of the full-tab battery is low, and the energy density of the battery is reduced.

SUMMERY OF THE UTILITY MODEL

In order to solve the technical problems, the utility model aims to provide a cylindrical high-power lithium battery structure with low internal resistance, small temperature rise and high safety by optimally adjusting the design of a lithium battery pole piece.

In order to achieve the purpose, the utility model provides the following technical scheme: the utility model provides a cylinder type high power lithium cell structure, includes cylindrical steel casing, explosion-proof block, busbar, rolls up core and electrolyte, its characterized in that: the top of the steel shell is connected with the anti-explosion cap in a rolling and sealing mode, a roll core and electrolyte are arranged inside the steel shell, the roll core is composed of a positive plate, a negative plate and two diaphragm plates, the positive plate is of an intermittent coating structure and comprises two polar lug positions, the inner polar lug and the outer polar lug are welded together through ultrasonic welding, then the inner polar lug and the outer polar lug are connected with the anti-explosion cap through laser welding, the negative plate is of a continuous coating structure, the upper end of the negative plate is an auxiliary material area, the lower end of the negative plate is a polar lug area, the negative polar lug is cut out in the polar lug area through laser cutting, the negative polar lug is connected with a busbar through laser welding, the busbar is welded with the bottom of the steel shell through a roll core center hole, and then the negative polar lug and the busbar are connected with the bottom of the steel shell through laser welding.

Preferably, the positive plate and the negative plate of the winding core are isolated by a diaphragm and are formed by winding through a winding needle, the auxiliary material area of the negative plate is completely covered by the diaphragm, the positive plate is completely covered by the negative plate, and a layer of expansion adhesive tape is pasted on the outer ring to serve as a termination adhesive tape.

Preferably, the inner tab and the outer tab are both nickel strips with large cross-sectional areas, and the inner tab is exposed for a long time, namely about 18-23 mm; the outer tab is exposed to a short distance of about 10-15 mm; the inner pole ear is connected with the explosion-proof cap by the inner pole ear after being welded with the outer pole ear.

Preferably, the negative pole tab is designed at equal intervals and needs to be subjected to tab inward folding treatment before being welded with the bus bar.

Preferably, the membrane sheet is a high-pore low-permeability composite membrane.

Preferably, the explosion-proof cap (2) is provided with a sealing ring made of PP material, the power-off value is 0.9-1.6MPa, and the explosion value is 1.8-2.8 MPa.

Preferably, there is the R angle chamfer bottom the box hat, and the surface plates the nickel layer of 2.0 ~ 7.0um thickness, and the internal surface plates the nickel layer of 0.5 ~ 1.0um thickness.

The utility model provides a cylindrical high-power lithium battery structure, and compared with the prior art, the technical scheme of the utility model has the following beneficial effects:

1. according to the utility model, the cathode adopts a continuous coating type multi-tab connection bus bar current guide design, and the anode adopts a wide tab structure design, so that the current density distribution homogenization degree is improved, the lithium precipitation of the battery cathode is avoided, the cycle service life of the battery is prolonged, and the safety of the battery is improved; meanwhile, the internal resistance of the battery can be effectively reduced, the large-current charging and discharging capacity is improved, the charging and discharging temperature rise is remarkably reduced, and the high-power requirement is met;

2. the utility model adopts the explosion-proof cap, thereby ensuring from the external structure of the battery, when the battery is overcharged and overdischarged, the battery firstly causes the internal electrolyte to generate decomposition reaction, a large amount of gas and heat are released, the anode of the battery can be automatically disconnected when the internal pressure accumulation of the battery reaches 0.9-1.6MPa, the battery can not be deteriorated after the battery is disconnected, if the battery is continuously deteriorated, the explosion-proof valve of the battery can be automatically broken when the internal pressure accumulation of the battery reaches 1.8-2.8MPa, the internal pressure is released, the battery can be further protected by double layers, the fire and explosion accidents can not occur, and the safety of the battery is improved.

3. The utility model adopts the expansion termination adhesive tape to replace the traditional termination adhesive tape, the adhesive tape generates expansion change after the action of certain high temperature and electrolyte, and can fill the gap between the battery cell and the steel shell, so that the battery cell and the steel shell are connected into a whole, the relative movement of the battery cell and the steel shell can be avoided when the battery is vibrated, the phenomena of single battery short circuit, tab desoldering and the like caused by vibration are solved, and the safety and the service life of the battery are further ensured and prolonged.

Drawings

The accompanying drawings, which are included to provide a further understanding of the utility model and are incorporated in and constitute a part of this specification, illustrate embodiments of the utility model and together with the description serve to explain the principles of the utility model and not to limit the utility model.

In the drawings:

FIG. 1 is a schematic view of a cylindrical high-power lithium battery according to the present invention;

FIG. 2 is a schematic view of the core of the present invention before winding;

FIG. 3 is a schematic structural diagram of a positive plate according to the present invention;

FIG. 4 is a schematic structural diagram of a negative electrode sheet according to the present invention;

reference numbers in the figures: 1. a steel shell; 2. an explosion-proof cap; 3. a winding core; 4. an electrolyte; 5. a positive plate; 51. An inner tab; 52. an outer tab; 6. a negative plate; 61. an auxiliary material area; 62. a polar ear region; 63. a negative electrode tab; 7. a diaphragm sheet; 8. a bus bar.

Detailed Description

The preferred embodiments of the present invention will be described in conjunction with the accompanying drawings, and it will be understood that they are described herein for the purpose of illustration and explanation and not limitation.

As shown in fig. 1-4, a cylindrical high-power lithium battery structure comprises a cylindrical steel shell, an explosion-proof cap, a busbar, a winding core and electrolyte, wherein the top of the steel shell 1 is connected with the explosion-proof cap 2 in a rolling and sealing manner, the winding core 3 and the electrolyte 4 are arranged inside the steel shell, the winding core 3 consists of a positive plate 5, a negative plate 6 and two diaphragm plates 7, the positive plate 5 is of a space coating structure and comprises two pole lug positions, an inner pole lug 51 and an outer pole lug 52 are welded together through ultrasonic welding and then connected with the explosion-proof cap 2 through laser welding, the negative plate 6 is of a continuous coating structure, the upper end of the negative plate is an auxiliary material area 61, the lower end of the negative plate is a pole lug area 62, a negative pole lug 63 is cut in the pole lug area 62 through laser cutting, the negative pole lug 63 is connected with the busbar 8 through laser welding, the busbar 8 is firstly subjected to point bottom welding through a center hole of the winding core, and welding the busbar with the bottom of the steel shell 1, and connecting the negative pole tab 63 and the busbar 8 with the bottom of the steel shell 1 through laser welding.

Preferably, the positive plate 5 and the negative plate 6 of the winding core 3 are separated by a diaphragm 7 and formed by winding with a winding needle, the diaphragm 7 completely covers the auxiliary material area of the negative plate 6, the negative plate 6 completely covers the positive plate 5, and a layer of expansion adhesive tape is pasted on the outer ring to serve as a termination adhesive tape.

Preferably, the inner tab 51 and the outer tab 52 both adopt nickel strips with larger cross-sectional areas, and the inner tab 51 is exposed for a long time, which is about 18-23 mm; the outer tab 52 is exposed to a short distance of about 10-15 mm; the inner pole ear 51 is welded with the outer pole ear 52 and then connected with the explosion-proof cap 2 through the inner pole ear 51.

Preferably, the negative electrode tabs 63 are designed at equal intervals and need to be subjected to tab inward folding treatment before being welded with the bus bar 8.

Preferably, the membrane sheet 7 is a high-pore low-permeability composite membrane.

Preferably, the explosion-proof cap 2 is provided with a sealing ring made of PP material, the power-off value is 0.9-1.6MPa, and the explosion value is 1.8-2.8 MPa.

Preferably, there is R angle chamfer 1 bottom of box hat, and the surface plates the nickel layer of 2.0 ~ 7.0um thickness, and the internal surface plates the nickel layer of 0.5 ~ 1.0um thickness.

Finally, it should be noted that: although the present invention has been described in detail with reference to the foregoing embodiments, it will be apparent to those skilled in the art that modifications may be made to the embodiments described above, or equivalents may be substituted for elements thereof. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. The utility model provides a cylinder type high power lithium cell structure which characterized in that: including cylindrical steel-shelled, explosion-proof block, busbar, book core and electrolyte, its characterized in that: the top of the steel shell (1) is connected with the anti-explosion cover cap (2) in a rolling sealing manner, a roll core (3) and electrolyte (4) are arranged inside the steel shell, the roll core (3) consists of a positive plate (5), a negative plate (6) and two diaphragm plates (7), the positive plate (5) is of a coating structure, the roll core comprises two polar lug positions, an inner polar lug (51) and an outer polar lug (52) are welded together through ultrasonic welding firstly and then connected with the anti-explosion cover cap (2) through laser welding, the negative plate (6) is of a coating structure, the upper end of the negative plate is an auxiliary material area (61), the lower end of the negative plate is a polar lug area (62), a negative polar lug (63) is cut out in the polar lug area (62) through laser cutting, the negative polar lug (63) is connected with a busbar (8) through laser welding, the busbar (8) is welded with the bottom of the steel shell (1) through a roll core center hole firstly, and then the negative pole tab (63) and the bus bar (8) are connected with the bottom of the steel shell (1) through laser welding.

2. The cylindrical high-power lithium battery structure as claimed in claim 1, wherein: the positive plate (5) and the negative plate (6) of the winding core (3) are isolated by the diaphragm (7) and are formed by winding a winding needle, the negative plate (6) auxiliary material area is completely covered by the diaphragm (7), the positive plate (5) is completely covered by the negative plate (6), and a layer of expansion adhesive tape is pasted on the outer ring to serve as a termination adhesive tape.

3. The cylindrical high-power lithium battery structure as claimed in claim 1, wherein: the inner tab (51) and the outer tab (52) both adopt nickel belts with larger cross-sectional areas, and the inner tab (51) is exposed for a long time, which is about 18-23 mm; the outer tab (52) is exposed to a short distance of about 10-15 mm; the inner tab (51) and the outer tab (52) are welded together and then connected with the explosion-proof cap (2) through the inner tab (51).

4. The cylindrical high power lithium battery structure as defined in claim 1, wherein: the negative pole tabs (63) are designed at equal intervals and need to be subjected to tab inward folding treatment before being welded with the busbar (8).

5. The cylindrical high-power lithium battery structure as claimed in claim 1, wherein: the diaphragm sheet (7) is a high-hole low-permeability composite diaphragm.

6. The cylindrical high-power lithium battery structure as claimed in claim 1, wherein: the explosion-proof cap (2) is provided with a sealing ring made of PP material, the power-off value is 0.9-1.6MPa, and the explosion value is 1.8-2.8 MPa.

7. The cylindrical high-power lithium battery structure as claimed in claim 1, wherein: there is the R angle chamfer bottom box hat (1), and the surface plates the nickel layer of 2.0 ~ 7.0um thickness, and the internal surface plates the nickel layer of 0.5 ~ 1.0um thickness.