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CN-122000557-A - Battery monomer, negative electrode plate, battery device and electricity utilization device

CN122000557ACN 122000557 ACN122000557 ACN 122000557ACN-122000557-A

Abstract

The application provides a battery cell, a negative electrode plate, a battery device and an electric device, wherein the battery cell comprises a negative electrode plate, a base coating arranged on at least one side of a negative electrode current collector, the base coating comprises a plurality of first protrusions protruding back to the negative electrode current collector and first concave parts between two adjacent first protrusions, the base coating comprises a first binder, an active material layer arranged on one side of the base coating back to the negative electrode current collector, the active material layer comprises a plurality of second protrusions protruding towards the base coating and second concave parts between two adjacent second protrusions, the active material layer comprises a second binder, the first protrusions and the second concave parts are arranged in a coupling mode, the second protrusions and the first concave parts are arranged in a coupling mode, and the mass content a of the first binder in the base coating is larger than the mass content b of the second binder in the active material layer. The battery device and the power utilization device have at least the beneficial effects.

Inventors

  • CHEN HUI
  • Guo Suogang
  • FU CHENGHUA
  • YE YONGHUANG

Assignees

  • 宁德时代新能源科技股份有限公司

Dates

Publication Date
20260508
Application Date
20241105

Claims (17)

  1. 1. The utility model provides a battery cell, its characterized in that includes electrode assembly, electrode assembly includes positive pole piece, negative pole piece and barrier film, the barrier film is located positive pole piece with between the negative pole piece, the negative pole piece includes: A negative electrode current collector; The bottom coating is arranged on at least one side of the negative electrode current collector and comprises a plurality of first bulges protruding back to the negative electrode current collector and first concave parts between two adjacent first bulges; An active material layer disposed on a side of the undercoat layer facing away from the negative electrode current collector, the active material layer including a plurality of second protrusions protruding toward the undercoat layer and second recesses between two adjacent second protrusions, the active material layer including a second binder; the first protrusion is coupled with the second recess, the second protrusion is coupled with the first recess, and the relation between the mass content a of the first binder in the base coat layer and the mass content b of the second binder in the active material layer satisfies a > b.
  2. 2. The battery cell according to claim 1, wherein a relation between a mass content a of the first binder in the undercoat layer and a mass content b of the second binder in the active material layer satisfies a:b= (2 to 10): 1.
  3. 3. The battery cell of claim 1 or 2, wherein the ratio of the thickness of the primer layer to the active material layer is (1:5) - (1:50).
  4. 4. The battery cell according to any one of claims 1 to 3, wherein the undercoat layer includes a first anode active material, the active material layer includes a second anode active material, and the first anode active material and the second anode active material satisfy one or more of the following conditions: 1) The ratio c of the average volume particle diameter Dv 1 of the first anode active material to the average volume particle diameter Dv 2 of the second anode active material satisfies (1:1) c (1:5); 2) The first anode active material has an average volume particle diameter Dv 1 50 of 1 to 20 μm; 3) The second anode active material has an average volume particle diameter Dv 2 50 of 2 to 40 μm; 4) The first and second anode active materials include one or more of artificial graphite and natural graphite; 5) The first and second anode active materials respectively further comprise one or more of silicon carbon material, silicon oxygen material, silicon nitrogen material, silicon alloy, lithium carbonate, titanium dioxide, titanate, amorphous carbon, transition metal oxide, transition metal sulfide and transition metal phosphide.
  5. 5. The battery cell of claim 4, wherein the primer layer and the active material layer have a peel strength of 5N/m to 15N/m.
  6. 6. The battery cell of any one of claims 1-5, wherein the primer layer satisfies one or more of the following conditions: 1) The thickness of the primer layer is 1 μm to 20 μm; 2) The mass content of the first negative electrode active material in the bottom coating is more than or equal to 50%; 3) The mass content a of the first binder in the bottom coating is 2% -10%; 4) The surface density of the primer layer is 0.1mg/cm 2 to 2mg/cm 2 ; 5) The ratio of the mass M of the undercoat layer to the sum M of the masses of the undercoat layer and the active material layer is 1% to 20%.
  7. 7. The battery cell of any one of claims 1-6, wherein the primer layer satisfies one or more of the following conditions: 1) The thickness of the primer layer is 5 μm to 15 μm; 2) The mass content of the first negative electrode active material in the bottom coating is 85% -95%; 3) The mass content a of the first binder in the bottom coating is 2% -5%; 4) The surface density of the primer layer is 1mg/cm 2 to 1.5mg/cm 2 ; 5) The ratio of the mass M of the undercoat layer to the sum M of the masses of the undercoat layer and the active material layer is 10% to 15%.
  8. 8. The battery cell according to any one of claims 1 to 7, wherein the active material layer satisfies one or more of the following conditions: 1) The mass content b of the second binder in the active material layer is 0.5% to 3%; 2) The thickness of the active material layer is 10 μm to 200 μm; 3) The mass content of the second anode active material in the active material layer is 70% to 98%; 4) The areal density of the active material layer is from 5mg/cm 2 to 20mg/cm 2 ; 5) The mass M' of the active material layer is 80 to 99% of the sum M of the masses of the undercoat layer and the active material layer.
  9. 9. The battery cell according to any one of claims 1 to 8, wherein the active material layer satisfies one or more of the following conditions: 1) The mass content b of the second binder in the active material layer is 0.5% to 1.5%; 2) The thickness of the active material layer is 50 μm to 150 μm; 3) The mass content of the second anode active material in the active material layer is 85% to 98%; 4) The areal density of the active material layer is from 10mg/cm 2 to 15mg/cm 2 ; 5) The mass M' of the active material layer is 85 to 90% of the sum M of the masses of the undercoat layer and the active material layer.
  10. 10. The battery cell of any one of claims 1-9, wherein the battery cell comprises an electrolyte comprising an electrolyte salt, an organic solvent, and a thioester additive comprising a structure represented by any one or more of formulas (1) to (6): wherein R1 and R2 each independently comprise a hydrogen atom, an alkyl group having 1 to 10 carbon atoms which is unsubstituted or substituted with a hetero atom, n, m are each integers, n is 1 to 4, and m is 0 to 4.
  11. 11. The battery cell according to claim 10, wherein R1 and R2 each independently include a hydrogen atom and an alkyl group having 1 to 4 carbon atoms.
  12. 12. The battery cell of claim 10 or 11, wherein the thioester additive comprises a structure as shown in any one or more of formulas (I-1) to (I-26):
  13. 13. The battery cell according to any one of claims 10 to 12, wherein the electrolyte satisfies one or more of the following conditions: 1) The mass content of the thioester additive in the electrolyte is 0.1 to 10%; 2) The concentration of the electrolyte salt in the electrolyte is 0.5mol/L to 3mol/L; 3) The mass content of the organic solvent in the electrolyte is 60% to 90%.
  14. 14. The battery cell according to any one of claims 10 to 13, wherein the electrolyte satisfies one or more of the following conditions: 1) The mass content of the thioester additive in the electrolyte is 0.5 to 2%; 2) The concentration of the electrolyte salt in the electrolyte is 0.8mol/L to 1.2mol/L; 3) The mass content of the organic solvent in the electrolyte is 80% to 88%.
  15. 15. A negative electrode tab, comprising: A negative electrode current collector; The bottom coating is arranged on at least one side of the negative electrode current collector and comprises a plurality of first bulges protruding back to the negative electrode current collector and first concave parts between two adjacent first bulges; An active material layer disposed on a side of the undercoat layer facing away from the negative electrode current collector, the active material layer including a plurality of second protrusions protruding toward the undercoat layer and second recesses between two adjacent second protrusions, the active material layer including a second binder; the first protrusion is coupled with the second recess, the second protrusion is coupled with the first recess, and the relation between the mass content a of the first binder in the base coat layer and the mass content b of the second binder in the active material layer satisfies a > b.
  16. 16. A battery device, characterized by comprising the battery cell of any one of claims 1-14 or the battery cell formed by preparing the negative electrode sheet of claim 15.
  17. 17. An electrical device comprising the battery device of claim 16.

Description

Battery monomer, negative electrode plate, battery device and electricity utilization device Technical Field The application belongs to the technical field of battery cells, and particularly relates to a battery cell, a negative pole piece, a battery device and an electricity utilization device. Background In recent years, battery cells have been widely used in energy storage power systems such as hydraulic power, thermal power, wind power and solar power stations, and in various fields such as electric tools, electric bicycles, electric motorcycles, electric vehicles, military equipment, aerospace, and the like. With the application and popularization of the battery cells, the comprehensive performance of the battery cells is paid more attention to, for example, the battery cells need to meet the requirements of high reliability, strong charging performance and the like. The negative electrode of the battery cell can play a role of deintercalating active ions, which is one of key factors affecting the performance of the battery cell. Therefore, it is desirable to provide a battery cell with good overall performance. Disclosure of Invention The application provides a battery cell which is good in dynamic performance and cycle life, the negative electrode plate is good in bonding stability and active ion transmission effect, and a battery device and an electric device comprising the battery cell have at least the beneficial effects. According to the embodiment of the application, the battery cell comprises a positive electrode plate, a negative electrode plate and a separation film, the separation film is positioned between the positive electrode plate and the negative electrode plate, the negative electrode plate comprises a negative electrode current collector, an undercoat layer is arranged on at least one side of the negative electrode current collector and comprises a plurality of first protrusions protruding away from the negative electrode current collector and first concave portions between two adjacent first protrusions, the undercoat layer comprises a first binder, an active material layer is arranged on one side of the undercoat layer away from the negative electrode current collector and comprises a plurality of second protrusions protruding towards the undercoat layer and second concave portions between two adjacent second protrusions, the active material layer comprises a second binder, the first protrusions and the second concave portions are arranged in a coupling mode, the second protrusions and the first concave portions are arranged in a coupling mode, and the relation between the mass content a of the first binder in the undercoat layer and the mass content b of the second binder in the active material layer is satisfied that a > b. In the embodiment of the application, the first bulge is arranged in a coupling way with the second concave part, and the second bulge is arranged in a coupling way with the first concave part, so that the contact area of the bottom coating and the active material layer can be increased, the bonding degree of two interfaces is improved, the bonding effect of the bottom coating and the active material layer is improved, the cycle life of a battery cell is prolonged, and the bottom coating and the active material layer have good bonding effect, so that the adhesive consumption required by the active material layer can be reduced, the peeling strength between the bottom coating and the active material layer is not influenced, the ion guiding effect of the negative electrode plate is improved, and the dynamic performance of the battery cell is improved on the basis that the bottom coating and the active material layer have good bonding effect, which can be understood as the negative electrode plate structure is stable. In some alternative embodiments, the relation between the mass content a of the first binder in the primer layer and the mass content b of the second binder in the active material layer satisfies a: b= (2-10): 1. In the embodiment of the application, the interface of the bottom coating layer contacted with the active material layer has an uneven structure, and the bonding effect of the bottom coating layer and the active material layer is considered, so that the ratio of the mass content a of the first binder to the mass content b of the second binder is set in the range, the binder content in the active material layer can be further reduced, the active ion transmission or deintercalation efficiency in the active material layer is improved, and the dynamic performance of the battery monomer is improved. In some alternative embodiments, the ratio of the thickness of the primer layer to the active material layer is (1:5) to (1:50). The thickness ratio of the primer layer to the active material layer in the above range can reduce the thickness of the primer layer and the duty ratio of the primer layer to the pole piece, and reduce the influence of the