Tabless nickel-metal hydride battery

Abstract

The present application provides a tab-free nickel-metal hydride battery. The tab-free nickel-metal hydride battery includes a staggered battery cell, a nickel-metal hydride battery shell, a top cover and a nickel foam layer; the staggered battery cell includes a positive electrode sheet, a diaphragm and a negative electrode sheet, the positive electrode sheet includes a first overlapping portion and a first connecting portion, the first overlapping portion is coated on the diaphragm, and the first connecting portion is exposed outside the diaphragm, the negative electrode sheet includes a second overlapping portion and a second connecting portion, the second overlapping portion is attached to the side of the diaphragm away from the first overlapping portion, the second connecting portion is exposed outside the diaphragm, and the first connecting portion and the second connecting portion are respectively located at both ends of the diaphragm; the nickel foam layer includes a first nickel foam layer and a second nickel foam layer, the first nickel foam layer is electrically connected to the top cover and the first connecting portion, respectively, and the second nickel foam layer is electrically connected to the nickel-metal hydride battery shell and the second connecting portion, respectively. The tab-free nickel-metal hydride battery can effectively reduce battery resistance, reduce battery mass and improve battery energy density.

Description

Technical Field

[0001] The invention relates to the technical field of secondary batteries, in particular to a tab-free nickel-hydrogen battery. Background Art

[0002] A secondary battery (rechargeable battery), also known as a rechargeable battery or storage battery, refers to a battery that can be used again by recharging the active material after the battery is discharged. A new battery can be constructed by utilizing the reversibility of chemical reactions, that is, after a chemical reaction is converted into electrical energy, the chemical system can be repaired by electrical energy, and then converted into electrical energy by chemical reactions again, so it is called a secondary battery (rechargeable battery). The main rechargeable batteries on the market include nickel-metal hydride batteries, nickel-cadmium batteries, lead-acid (or lead storage) batteries, lithium-ion batteries, polymer lithium-ion batteries, etc.

[0003] As fossil fuels are becoming less and less in the case of large-scale development and utilization by humans, the development and utilization of hydrogen energy has received increasing attention in recent years. Nickel-hydrogen batteries, as an important direction for the application of hydrogen energy, are increasingly attracting people's attention. The current collector in nickel-hydrogen batteries is an important component of the battery. The commonly used current collector is a thicker copper foil or aluminum foil, which accounts for 20% to 40% of the total weight of the nickel-hydrogen battery, resulting in a decrease in the energy density of the nickel-hydrogen battery; at the same time, the existing nickel-hydrogen batteries use pole ears for welding when welding the current collector, which not only increases the welding resistance between the pole ears and the metal shell, thereby increasing the battery resistance, but also increases the battery mass and reduces the battery energy density. Summary of the invention

[0004] The purpose of the present invention is to overcome the deficiencies in the prior art and provide a tab-free nickel-hydrogen battery capable of reducing battery resistance, reducing battery mass and improving battery energy density.

[0005] The objective of the present invention is achieved through the following technical solutions:

[0006] A tab-free nickel-hydrogen battery, comprising:

[0007] A staggered battery cell, the staggered battery cell comprising a positive electrode sheet, a separator and a negative electrode sheet, the positive electrode sheet comprising a first overlapping portion and a first connecting portion, the first overlapping portion being coated on the separator, the first connecting portion being exposed outside the separator, the negative electrode sheet comprising a second overlapping portion and a second connecting portion, the second overlapping portion being in contact with a side of the separator away from the first overlapping portion, the second connecting portion being exposed outside the separator, the first connecting portion and the second connecting portion being located at two ends of the separator respectively;

[0008] A nickel-metal hydride battery housing, wherein the nickel-metal hydride battery housing is provided with a receiving cavity, and the staggered battery cell is placed in the receiving cavity;

[0009] A top cover, which is insulated and connected to the nickel-metal hydride battery housing, and the top cover covers the nickel-metal hydride battery housing;

[0010] A nickel foam layer, which includes a first nickel foam layer and a second nickel foam layer. The first nickel foam layer is electrically connected to the top cover and the first connecting portion respectively, and the second nickel foam layer is electrically connected to the nickel-metal hydride battery housing and the second connecting portion respectively.

[0011] In one embodiment, the first nickel foam layer is in interference fit with the top cover and the first connecting portion respectively.

[0012] In one embodiment, the second nickel foam layer is in interference fit with the nickel-metal hydride battery housing and the second connecting portion respectively.

[0013] In one embodiment, the earless nickel-metal hydride battery further includes an insulating sealing rubber ring, which is clamped between the top cover and the nickel-metal hydride battery housing.

[0014] In one embodiment, the width of the first overlapping portion is the same as the width of the second overlapping portion.

[0015] In one embodiment, the width of the first connecting portion is the same as the width of the second connecting portion.

[0016] In one embodiment, the top cover includes a housing and a cap body, the cap body is connected to the housing, and the cap body is in interference fit with the first nickel foam layer.

[0017] In one embodiment, the top cover further includes a resettable safety valve, and the resettable safety valve is installed in the cap body.

[0018] In one embodiment, the thickness of the first nickel foam layer is the same as the thickness of the second nickel foam layer.

[0019] In one embodiment, a clamping groove is formed on one side of the nickel-metal hydride battery housing close to the top cover.

[0020] Compared with the prior art, the present invention has at least the following advantages:

[0021] 1. The tab-free nickel-hydrogen battery of the present invention includes a staggered battery cell, which includes a positive electrode sheet, a diaphragm and a negative electrode sheet. Since the positive electrode sheet includes a first overlapping portion and a first connecting portion, the first overlapping portion is coated on the diaphragm, and the first connecting portion is exposed outside the diaphragm, so that the first connecting portion can be connected to the top cover of the nickel-hydrogen battery, thereby extracting the current in the positive electrode sheet; and since the negative electrode sheet includes a second overlapping portion and a second connecting portion, the second overlapping portion is attached to the side of the diaphragm away from the first overlapping portion, and the second connecting portion is exposed outside the diaphragm, so that the second connecting portion can be connected to the shell of the nickel-hydrogen battery, thereby extracting the current in the negative electrode sheet. In addition, the nickel-hydrogen battery shell is provided with a receiving cavity, the staggered battery cell is placed in the receiving cavity, the top cover is insulated and connected to the nickel-hydrogen battery shell, and the top cover is provided on the nickel-hydrogen battery shell. In this way, the nickel-hydrogen battery can omit the tab, avoid the internal resistance of the tab welding, thereby effectively reducing the battery resistance of the nickel-hydrogen battery, and at the same time, the use of the tab-free method can effectively reduce the mass of the nickel-hydrogen battery and improve the energy density of the battery.

[0022] 2. The tab-free nickel-hydrogen battery of the present invention also includes a foam nickel layer, and the foam nickel layer includes a first foam nickel layer and a second foam nickel layer. Since the first foam nickel layer is electrically connected to the top cover and the first connecting part respectively, the conductivity of the first connecting part can be effectively improved without welding. While realizing tab-free, the welding operation can be avoided, thereby further reducing the battery resistance and improving the battery performance. Since the second foam nickel layer is electrically connected to the nickel-hydrogen battery shell and the second connecting part respectively, the conductivity of the second connecting part can be effectively improved without welding. While realizing tab-free, the welding operation can be avoided, thereby further reducing the battery resistance and improving the battery performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0024] Figure 1 This is a schematic diagram of the structure of a tab-free nickel-hydrogen battery in one embodiment;

[0025] Figure 2 for Figure 1 A cross-sectional view of a tab-free nickel-hydrogen battery;

[0026] Figure 3 for Figure 1 The schematic diagram of the structure of the staggered battery cell in the tab-free nickel-hydrogen battery shown;

[0027] Figure 4 for Figure 3A partial expanded schematic diagram of the staggered battery cell shown;

[0028] Figure 5 for Figure 3 A partial expanded schematic diagram of the staggered battery cell from another perspective is shown. DETAILED DESCRIPTION

[0029] In order to facilitate the understanding of the present invention, the present invention will be described more fully below with reference to the relevant drawings. The preferred embodiments of the present invention are given in the drawings. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present invention more thoroughly understood.

[0030] It should be noted that when an element is referred to as being "fixed to" another element, it may be directly on the other element or there may be a central element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are for illustrative purposes only and do not represent the only implementation method.

[0031] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more related listed items.

[0032] The present application provides a tab-free nickel-metal hydride battery. The tab-free nickel-metal hydride battery includes a staggered battery cell, a nickel-metal hydride battery shell, a top cover and a nickel foam layer; the staggered battery cell includes a positive electrode sheet, a diaphragm and a negative electrode sheet, the positive electrode sheet includes a first overlapping portion and a first connecting portion, the first overlapping portion is coated on the diaphragm, the first connecting portion is exposed outside the diaphragm, the negative electrode sheet includes a second overlapping portion and a second connecting portion, the second overlapping portion is attached to the side of the diaphragm away from the first overlapping portion, the second connecting portion is exposed outside the diaphragm, and the first connecting portion and the second connecting portion are respectively located at both ends of the diaphragm; the nickel-metal hydride battery shell is provided with a receiving cavity, and the staggered battery cell is placed in the receiving cavity; the top cover is insulated and connected to the nickel-metal hydride battery shell, and the top cover is provided on the nickel-metal hydride battery shell; the nickel foam layer includes a first nickel foam layer and a second nickel foam layer, the first nickel foam layer is electrically connected to the top cover and the first connecting portion respectively, and the second nickel foam layer is electrically connected to the nickel-metal hydride battery shell and the second connecting portion respectively.

[0033] See alsoFigure 1 , which is a schematic diagram of a tab-free nickel-hydrogen battery 10 in one embodiment.

[0034] See also Figure 2 , Figure 4 and Figure 5 The tab-free nickel-metal hydride battery 10 of one embodiment includes a staggered battery cell 100, a nickel-metal hydride battery shell 200, a top cover 300 and a nickel foam layer 400; the staggered battery cell 100 includes a positive electrode sheet 110, a diaphragm 120 and a negative electrode sheet 130, the positive electrode sheet 110 includes a first overlapping portion 111 and a first connecting portion 113, the first overlapping portion 111 is coated on the diaphragm 120, and the first connecting portion 113 is exposed outside the diaphragm 120, the negative electrode sheet 130 includes a second overlapping portion 131 and a second connecting portion 133, the second overlapping portion 131 is attached to a side of the diaphragm 120 away from the first overlapping portion 111, and the second connecting portion 133 is exposed. Exposed outside the diaphragm 120, the first connection part 113 and the second connection part 133 are respectively located at the two ends of the diaphragm 120; the nickel-hydrogen battery shell 200 is provided with a accommodating cavity 202, and the staggered battery cell 100 is placed in the accommodating cavity 202; the top cover 300 is insulated and connected to the nickel-hydrogen battery shell 200, and the top cover 300 is covered on the nickel-hydrogen battery shell 200; the foam nickel layer 400 includes a first foam nickel layer 410 and a first foam nickel layer 420, the first foam nickel layer 410 is electrically connected to the top cover 300 and the first connection part 113, respectively, and the first foam nickel layer 420 is electrically connected to the nickel-hydrogen battery shell 200 and the second connection part 133, respectively.

[0035] The above-mentioned tab-free nickel-hydrogen battery 10 includes a staggered battery cell 100, which includes a positive electrode sheet 110, a diaphragm 120 and a negative electrode sheet 130. Since the positive electrode sheet 110 includes a first overlapping portion 111 and a first connecting portion 113, the first overlapping portion 111 is coated on the diaphragm 120, and the first connecting portion 113 is exposed outside the diaphragm 120, so that the first connecting portion 113 can be connected to the top cover 300 of the nickel-hydrogen battery, thereby extracting the current in the positive electrode sheet 110; and since the negative electrode sheet 130 includes a second overlapping portion 131 and a second connecting portion 133, the second overlapping portion 131 is attached to the side of the diaphragm 120 away from the first overlapping portion 111, and the second connecting portion 133 is exposed outside the diaphragm 120, so that the second connecting portion 133 can be connected to the shell of the nickel-hydrogen battery, thereby extracting the current in the negative electrode sheet 130. In addition, the nickel-hydrogen battery shell 200 is provided with a accommodating cavity 202, the staggered battery cell 100 is placed in the accommodating cavity 202, the top cover 300 is insulated and connected to the nickel-hydrogen battery shell 200, and the top cover 300 is covered on the nickel-hydrogen battery shell 200. In this way, the nickel-hydrogen battery can omit the pole ear and avoid the internal resistance of the pole ear welding, thereby effectively reducing the battery resistance of the nickel-hydrogen battery. At the same time, the use of a pole ear-free method can effectively reduce the mass of the nickel-hydrogen battery and improve the energy density of the battery. The present application also includes a nickel foam layer 400, which includes a first nickel foam layer 410 and a first nickel foam layer 420. Since the first nickel foam layer 410 is electrically connected to the top cover 300 and the first connecting part 113, respectively, the conductivity of the first connecting part 113 can be effectively improved without welding. While achieving the tab-free state, the welding operation can be avoided, thereby further reducing the battery resistance and improving the battery performance. Since the first nickel foam layer 420 is electrically connected to the nickel-hydrogen battery shell 200 and the second connecting part 133, respectively, the conductivity of the second connecting part 133 can be effectively improved without welding. While achieving the tab-free state, the welding operation can be avoided, thereby further reducing the battery resistance and improving the battery performance.

[0036] like Figure 2As shown, in one embodiment, the first nickel foam layer 410 is in interference fit with the top cover 300 and the first connecting portion 113 respectively. Since nickel foam has good elasticity, after the first nickel foam layer 410 is in interference fit with the top cover 300 and the first connecting portion 113 respectively, the positive electrode of the earless nickel-metal hydride battery 10 can maintain stable elastic electrical connection. Thus, while eliminating the welding operation, the stability of the electrical connection of the electrode can be effectively improved. Moreover, nickel foam has good electrical conductivity and conductive stability, which can further reduce the battery resistance and improve the battery performance at the same time. In this embodiment, one side of the first nickel foam layer 410 is in interference fit with the cap portion of the top cover 300, and the other side of the first nickel foam layer 410 is in interference fit with the first connecting portion 113, and the nickel foam layer 400 has good elasticity, so as to realize the elastic electrical connection of the positive electrode of the earless nickel-metal hydride battery 10. On the one hand, it can ensure the tightness and stability of the electrical connection after the earless nickel-metal hydride battery 10 is encapsulated, thereby improving the electrical performance of the earless nickel-metal hydride battery 10; on the other hand, since the first nickel foam layer 410 can realize welding-free, the problem of increased resistance caused by welding is reduced, so as to effectively reduce the resistance of the positive electrode of the earless nickel-metal hydride battery 10, and further effectively reduce the resistance of the earless nickel-metal hydride battery 10.

[0037] As Figure 2 shown, in one embodiment, the first nickel foam layer 420 is in interference fit with the nickel-metal hydride battery housing 200 and the second connecting portion 133 respectively. Since nickel foam has good elasticity, after the first nickel foam layer 410 is in interference fit with the top cover 300 and the first connecting portion 113 respectively, the negative electrode of the earless nickel-metal hydride battery 10 can maintain stable elastic electrical connection. Thus, while eliminating the welding operation, the stability of the electrical connection of the electrode can be effectively improved. Moreover, nickel foam has good electrical conductivity and conductive stability, which can further reduce the battery resistance and improve the battery performance at the same time. In this embodiment, one side of the first nickel foam layer 420 is in interference fit with the bottom of the nickel-metal hydride battery housing 200, and the other side of the first nickel foam layer 420 is in interference fit with the second connecting portion 133, and the nickel foam layer 400 has good elasticity, so as to realize the elastic electrical connection of the negative electrode of the earless nickel-metal hydride battery 10. On the one hand, it can ensure the tightness and stability of the electrical connection after the earless nickel-metal hydride battery 10 is encapsulated, thereby improving the electrical performance of the earless nickel-metal hydride battery 10; on the other hand, since the first nickel foam layer 420 can realize welding-free, the problem of increased resistance caused by welding is reduced, so as to effectively reduce the resistance of the negative electrode of the earless nickel-metal hydride battery 10, and further effectively reduce the resistance of the earless nickel-metal hydride battery 10.

[0038] As Figure 2As shown, in order to better isolate the positive electrode tab of the battery and the nickel-metal hydride battery housing 200 , in one embodiment, the tab-free nickel-metal hydride battery 10 further includes an insulating sealing rubber ring 500 , which is sandwiched between the top cover 300 and the nickel-metal hydride battery housing 200 . It can be understood that the top cover 300 is insulated and connected to the nickel-metal hydride battery shell 200. In order to further improve the insulation effect between the top cover 300 and the nickel-metal hydride battery shell 200, in this embodiment, the tab-free nickel-metal hydride battery 10 also includes an insulating sealing rubber ring 500. The diameter of the insulating sealing rubber layer is consistent with the diameter of the top cover 300 and the diameter of the nickel-metal hydride battery shell 200. The insulating sealing rubber ring 500 is clamped between the top cover 300 and the nickel-metal hydride battery shell 200, that is, one side of the insulating sealing rubber ring 500 is in contact with the inner wall edge of the top cover 300, and the other side of the insulating sealing rubber ring 500 is in contact with the side of the nickel-metal hydride battery shell 200 close to the inner wall of the top cover 300. Moreover, the insulating sealing rubber layer has good elasticity and insulation, so that the connection between the top cover 300 and the nickel-metal hydride battery shell 200 is better, and the insulation effect between the top cover 300 and the nickel-metal hydride battery shell 200 can be improved, and the battery positive pole ear and the nickel-metal hydride battery shell 200 can be better isolated.

[0039] In one embodiment, the width of the first overlapping portion 111 is the same as the width of the second overlapping portion 131. It can be understood that, since the positive electrode sheet 110 includes the first overlapping portion 111 and the first connecting portion 113, the first overlapping portion 111 is covered by the diaphragm 120, and the first connecting portion 113 is exposed outside the diaphragm 120, so that the first connecting portion 113 can be connected to the top cover 300 of the nickel-hydrogen battery, thereby extracting the current in the positive electrode sheet 110; and since the negative electrode sheet 130 includes the second overlapping portion 131 and the second connecting portion 133, the second overlapping portion 131 is attached to the side of the diaphragm 120 away from the first overlapping portion 111, and the second connecting portion 133 is exposed outside the diaphragm 120, so that the second connecting portion 133 can be connected to the shell of the nickel-hydrogen battery, thereby extracting the current in the negative electrode sheet 130. The first overlapping portion 111, the diaphragm 120 and the second overlapping portion 131 are stacked and wound in sequence, so that the positive electrode sheet 110, the diaphragm 120 and the negative electrode sheet 130 are wound to form a staggered battery cell 100. In order to prevent the problem of positive and negative short circuit in the staggered battery cell 100 during the winding process and save the diaphragm 120 material, in the present embodiment, the first overlapping portion 111, the diaphragm 120 and the second overlapping portion 131 are stacked and wound in sequence, and the width of the first overlapping portion 111 is the same as the width of the second overlapping portion 131, so that the diaphragm 120 can fully isolate the positive electrode sheet 110 and the negative electrode sheet 130, and avoid the positive electrode sheet 110, the diaphragm 120 and the negative electrode sheet 130 from being staggered and stacked to produce excess diaphragm 120, thereby saving diaphragm 120 material, improving the compactness of the staggered battery cell 100, and reducing the mass of the tab-free nickel-hydrogen battery 10.

[0040] In one embodiment, the width of the first connection portion 113 is the same as the width of the second connection portion 133. It is understood that, since the positive electrode sheet 110 includes the first overlapping portion 111 and the first connection portion 113, the first overlapping portion 111 is covered by the diaphragm 120, and the first connection portion 113 is exposed outside the diaphragm 120, so that the first connection portion 113 can be connected to the top cover 300 of the nickel-hydrogen battery, thereby extracting the current in the positive electrode sheet 110; and since the negative electrode sheet 130 includes the second overlapping portion 131 and the second connection portion 133, the second overlapping portion 131 is attached to the side of the diaphragm 120 away from the first overlapping portion 111, and the second connection portion 133 is exposed outside the diaphragm 120, so that the second connection portion 133 can be connected to the shell of the nickel-hydrogen battery, thereby extracting the current in the negative electrode sheet 130. In order to improve the structural consistency of the anode-free nickel-metal hydride battery 10, in the present embodiment, the first connecting portion 113 and the second connecting portion 133 are respectively arranged at the two ends of the nickel-metal hydride battery, and the width of the first connecting portion 113 is the same as the width of the second connecting portion 133, which can effectively improve the structural consistency of the anode-free nickel-metal hydride battery 10 and improve the stability of the anode-free nickel-metal hydride battery 10.

[0041] like Figure 2 , Figure 3 , Figure 4 and Figure 5As shown, in one embodiment, the first connection portion 113 includes a first blank area 1131 and a first coating area 1133. The first coating area 1133 is connected to the first blank area 1131. The first blank area 1131 is used for electrically connecting to the top cover 300 of the nickel-metal hydride battery. The first coating area 1133 is connected to the first overlapping portion 111. A first cured adhesive layer 610 is coated on the coating area, and the first cured adhesive layer 610 is partially attached to the separator 120. In this embodiment, the electrical connection of the positive electrode of the nickel-metal hydride battery can be achieved through the first blank area 1131. In this way, the positive electrode tab of the nickel-metal hydride battery can be omitted, avoiding the internal resistance of the positive electrode tab welding, thereby effectively reducing the battery resistance of the nickel-metal hydride battery. At the same time, the use of the tabless method can effectively reduce the mass of the nickel-metal hydride battery and improve the energy density of the battery. Further, since the first connection portion 113 has only one positive electrode sheet 110, the structural strength of the first connection portion 113 is weaker than that of the overlapping portion of the offset-type battery cell 100. By coating a first cured adhesive layer 610 on the first coating area 1133 of the first connection portion 113, on the one hand, the thickness of the first connection portion 113 can be increased, and the structural strength of the first connection portion 113 can be improved; on the other hand, the first cured adhesive layer 610 has good insulation, and the first cured adhesive layer 610 is partially attached to the separator 120, that is, the first cured adhesive layer 610 and the separator 120 have an overlapping portion, so as to further prevent the positive electrode sheet 110 exposed outside the separator 120, that is, the first connection portion 113 from short-circuiting with the negative electrode sheet 130, thereby improving the stability of the offset-type battery cell 100 and the stability of the tabless nickel-metal hydride battery 10. In addition, the first cured adhesive layer 610 also has a good anti-internal corrosion effect, thereby further improving the performance stability of the tabless nickel-metal hydride battery 10.

[0042] As Figure 2 , Figure 3 , Figure 4 and Figure 5As shown, in one of the embodiments, the second connecting portion 133 includes a second blank area 1331 and a second coating area 1333. The second coating area 1333 is connected to the second blank area 1331. The second blank area 1331 is used for electrically connecting to the top cover 300 of the nickel-metal hydride battery. The second coating area 1333 is connected to the second overlapping portion 131. A second cured adhesive layer 620 is coated on the second coating area 1333, and the second cured adhesive layer 620 is partially adhered to the separator 120. In this embodiment, the electrical connection of the negative electrode of the nickel-metal hydride battery can be achieved through the second blank area 1331. In this way, the negative electrode tab of the nickel-metal hydride battery can be omitted, avoiding the internal resistance of the negative electrode tab welding, thereby effectively reducing the battery resistance of the nickel-metal hydride battery. At the same time, the use of the tabless method can effectively reduce the mass of the nickel-metal hydride battery and improve the energy density of the battery. Further, since the second connecting portion 133 has only one negative electrode sheet 130, the structural strength of the second connecting portion 133 is weaker than that of the overlapping portion of the offset type battery cell 100. By coating a second cured adhesive layer 620 on the second coating area 1333 of the second connecting portion 133, on the one hand, the thickness of the second connecting portion 133 can be increased, and the structural strength of the second connecting portion 133 can be improved; on the other hand, the second cured adhesive layer 620 has good insulation, and the second cured adhesive layer 620 is partially adhered to the separator 120, that is, the second cured adhesive layer 620 and the separator 120 have an overlapping portion, so as to further prevent the negative electrode sheet 130 exposed outside the separator 120, that is, a short circuit occurs between the second connecting portion 133 and the negative electrode sheet 130, thereby improving the stability of the offset type battery cell 100 and the stability of the tabless nickel-metal hydride battery 10. In addition, the second cured adhesive layer 620 also has a good anti-internal corrosion effect, thereby further improving the performance stability of the tabless nickel-metal hydride battery 10.

[0043] As Figure 1 and Figure 2As shown, in one embodiment, the top cover 300 includes a housing 310 and a cap body 320. The cap body 320 is connected to the housing 310 and is in interference fit with the first nickel foam layer 410. It can be understood that power batteries using different cathode materials and electrolytes have temperature and voltage change curves with different characteristics during overcharging. When overcharging reaches a certain level, if the internal temperature of the power battery has reached the thermal runaway state, the internal pressure continues to rise, and the explosion-proof film will be broken through, and the substances inside the power battery will be ejected with the high-pressure gas. In this embodiment, the cap body 320 has an overcharging protection function. When overcharging reaches a certain level, it can terminate the charging in time, thereby improving the safety of the earless nickel-metal hydride battery 10. In addition, one side of the cap body 320 is in interference fit with the first nickel foam layer 410, and the other side of the first nickel foam layer 410 is in interference fit with the first connecting portion 113, thereby effectively improving the stability and fixity of the elastic electrical connection between the first nickel foam layer 410 and the misaligned battery cell 100 and the top cover 300, and further reducing the battery resistance and improving the energy density of the earless nickel-metal hydride battery 10.

[0044] As Figure 2 shown, further, the top cover 300 further includes a resettable safety valve 330, and the resettable safety valve 330 is installed in the cap body. It can be understood that during the charging process of the earless nickel-metal hydride battery 10, especially during fast charging with a large current, more gas may be generated inside the battery, causing the internal pressure of the battery to increase. High internal pressure is likely to cause liquid (gas) leakage, alkali creep, drying of the separator 120, and shortening of the battery life. To improve the safety of the earless nickel-metal hydride battery 10, in this embodiment, the top cover 300 further includes a resettable safety valve 330, and the resettable safety valve 330 is installed in the cap body. The resettable safety valve is used to complete the sealing of the earless nickel-metal hydride battery 10. When the internal pressure of the battery is too high, the resettable safety valve 330 opens to release gas and reduce the internal pressure of the battery, thereby improving the safety of the earless nickel-metal hydride battery 10. In addition, the resettable safety valve 330 has a good reset effect, thereby further improving the stability of the earless nickel-metal hydride battery 10.

[0045] In one embodiment, the thickness of the first nickel foam layer 410 is the same as that of the first nickel foam layer 420. It can be understood that since the first nickel foam layer 410 is electrically connected to the top cover 300 and the first connecting portion 113 respectively, the conductivity of the first connecting portion 113 can be effectively improved, and welding is not required. While realizing the earless design, the welding operation can be eliminated, thereby further reducing the battery resistance and improving the battery performance. Also, since the first nickel foam layer 420 is electrically connected to the nickel-metal hydride battery case 200 and the second connecting portion 133 respectively, the conductivity of the second connecting portion 133 can be effectively improved, and welding is not required. While realizing the earless design, the welding operation can be eliminated, thereby further reducing the battery resistance and improving the battery performance. To further improve the structural consistency and electrical conductivity consistency of the earless nickel-metal hydride battery 10, in this embodiment, the first nickel foam layer 410 and the first nickel foam layer 410 are respectively disposed at both ends of the earless nickel-metal hydride battery 10, and the thickness of the first nickel foam layer 410 is the same as that of the first nickel foam layer 420, which can effectively improve the structural consistency of the earless nickel-metal hydride battery 10, improve the stability of the earless nickel-metal hydride battery 10, and at the same time improve the electrical conductivity consistency of the earless nickel-metal hydride battery 10.

[0046] As Figure 1 and Figure 2 shown, in one embodiment, a clamping groove 204 is formed on one side of the nickel-metal hydride battery case 200 close to the top cover 300. In this embodiment, the top cover 300 is insulated from the nickel-metal hydride battery case 200, and the top cover 300 covers the nickel-metal hydride battery case 200. By forming the clamping groove 204 on one side of the nickel-metal hydride battery case 200 close to the top cover 300, the top cover 300 can be clamped in the clamping groove 204, thereby improving the stability when the top cover 300 covers the nickel-metal hydride battery case, and further improving the structural stability of the earless nickel-metal hydride battery 10. In addition, the clamping groove 204 can also function as an explosion-proof groove, achieving a good explosion-proof effect.

[0047] Compared with the prior art, the present invention has at least the following advantages:

[0048] 1. The tab-free nickel-hydrogen battery 10 of the present invention includes a staggered battery cell 100, which includes a positive electrode sheet 110, a diaphragm 120 and a negative electrode sheet 130. Since the positive electrode sheet 110 includes a first overlapping portion 111 and a first connecting portion 113, the first overlapping portion 111 is coated on the diaphragm 120, and the first connecting portion 113 is exposed outside the diaphragm 120, so that the first connecting portion 113 can be connected to the top cover 300 of the nickel-hydrogen battery, thereby extracting the current in the positive electrode sheet 110; and since the negative electrode sheet 130 includes a second overlapping portion 131 and a second connecting portion 133, the second overlapping portion 131 is attached to a side of the diaphragm 120 away from the first overlapping portion 111, and the second connecting portion 133 is exposed outside the diaphragm 120, so that the second connecting portion 133 can be connected to the shell of the nickel-hydrogen battery, thereby extracting the current in the negative electrode sheet 130. In addition, the nickel-hydrogen battery shell 200 is provided with a accommodating cavity 202, the staggered battery cell 100 is placed in the accommodating cavity 202, the top cover 300 is insulated and connected to the nickel-hydrogen battery shell 200, and the top cover 300 is covered on the nickel-hydrogen battery shell 200. In this way, the nickel-hydrogen battery can omit the pole ear and avoid the internal resistance of the pole ear welding, thereby effectively reducing the battery resistance of the nickel-hydrogen battery. At the same time, the use of a pole ear-free method can effectively reduce the mass of the nickel-hydrogen battery and improve the energy density of the battery.

[0049] 2. The tab-free nickel-hydrogen battery 10 of the present invention further includes a nickel foam layer 400, and the nickel foam layer 400 includes a first nickel foam layer 410 and a first nickel foam layer 420. Since the first nickel foam layer 410 is electrically connected to the top cover 300 and the first connecting portion 113, respectively, the conductivity of the first connecting portion 113 can be effectively improved without welding. While realizing tab-free, the welding operation can also be avoided, thereby further reducing the battery resistance and improving the battery performance. Since the first nickel foam layer 420 is electrically connected to the nickel-hydrogen battery housing 200 and the second connecting portion 133, respectively, the conductivity of the second connecting portion 133 can be effectively improved without welding. While realizing tab-free, the welding operation can also be avoided, thereby further reducing the battery resistance and improving the battery performance.

[0050] The above embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for those of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. An earless nickel-metal hydride battery, characterized in that, include: A staggered battery cell, the staggered battery cell comprising a positive electrode sheet, a separator and a negative electrode sheet, the positive electrode sheet comprising a first overlapping portion and a first connecting portion, the first overlapping portion being coated on the separator, the first connecting portion being exposed outside the separator, the negative electrode sheet comprising a second overlapping portion and a second connecting portion, the second overlapping portion being in contact with a side of the separator away from the first overlapping portion, the second connecting portion being exposed outside the separator, the first connecting portion and the second connecting portion being located at two ends of the separator respectively; A nickel-metal hydride battery housing, wherein the nickel-metal hydride battery housing is provided with a receiving cavity, and the staggered battery cell is placed in the receiving cavity; A top cover, the top cover is insulated and connected to the nickel-hydrogen battery housing, and the top cover is disposed on the nickel-hydrogen battery housing; The nickel foam layer comprises a first nickel foam layer and a second nickel foam layer, the first nickel foam layer is electrically connected to the top cover and the first connecting portion respectively, and the second nickel foam layer is electrically connected to the nickel-metal hydride battery shell and the second connecting portion respectively; the first nickel foam layer is in interference contact with the top cover and the first connecting portion respectively, and the second nickel foam layer is in interference contact with the nickel-metal hydride battery shell and the second connecting portion respectively.

2. The earless nickel-metal hydride battery according to claim 1, characterized in that, It also includes an insulating sealing rubber ring, which is clamped between the top cover and the nickel-hydrogen battery shell.

3. The earless nickel-metal hydride battery according to claim 1, characterized in that, The width of the first overlapping portion is the same as the width of the second overlapping portion.

4. The earless nickel-metal hydride battery according to claim 1, characterized in that, The width of the first connection portion is the same as the width of the second connection portion.

5. The earless nickel-metal hydride battery according to claim 1, characterized in that, The top cover comprises a shell and a cap body, wherein the cap body is connected to the shell, and the cap body is in interference contact with the first nickel foam layer.

6. The earless nickel-metal hydride battery according to claim 5, characterized in that, The top cover also includes a recoverable safety valve, which is installed in the cap body.

7. The earless nickel-metal hydride battery according to claim 1, characterized in that, The thickness of the first nickel foam layer is the same as the thickness of the second nickel foam layer.

8. The earless nickel-metal hydride battery according to claim 1, characterized in that, A locking groove is provided on one side of the nickel-hydrogen battery housing close to the top cover.

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