High-rate lithium battery structure and implementation method

Abstract

The invention discloses a high-rate lithium battery structure which comprises a pole piece, the pole piece comprises a current collector and an active material coating which coats the surface of the current collector. The high-rate lithium battery structure is characterized in that a microstructure channel is formed on the surface of the active material coating, and the depth of the microstructure channel is less than or equal to the thickness of the active material coating, so that electrolyte can permeate into the deep part of the active material coating along the microstructure channel, so that the contact area between the electrolyte and the active material coating is increased. The invention also discloses an implementation method of the high-rate lithium battery. According to the high-rate lithium battery structure and the implementation method of the invention, by changing the form state of the coating on the surface of the pole piece, the surface area of the active coating is increased, so that deep active particles can be in contact with the electrolyte more quickly, and the diffusion path of lithium ions during charging and discharging can be re-planned, so that more lithium ions can be deintercalated and intercalated more quickly, the capacity of the battery is better exerted, particularly, the charging and discharging performance of the battery under high magnification is realized.

Description

technical field [0001] The invention relates to the technical field of lithium batteries, in particular to a structure and a realization method of a high-rate lithium battery. Background technique [0002] Lithium-ion batteries are developing rapidly and are widely used in automobiles, electronic equipment, etc., but due to their poor performance at high rates, that is, the capacity under high-rate charge and discharge is far less than that at low rates, and even cannot be discharged at high rates. It has become a new energy source. One of the pain points in the development of automobiles. [0003] Lithium-ion batteries often require better synchronization of battery capacity and high-rate performance. The battery capacity depends on the total amount of active materials in the pole piece and the utilization rate of material performance. Usually, the method of increasing the thickness of the pole piece is used to increase the active material content. However, with the increa...

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Problems solved by technology

[0002] Lithium-ion batteries are developing rapidly and are widely used in automobiles and electronic equipment. However, due to poor high-rate performance, that is, the capacity performance under high-rate charging and discharging is far inferior to that of low-rate, and even cannot be discharged under high-rate. It has become a new energy source. One of the pain points in the development of automobiles

[0003] Lithium-ion batteries often require better synchronous capacity and high-rate performance of the battery. The battery capacity depends on the total amount of active material in the pole piece and the utilization rate of material performance. Usually, the method of increasing the thickness of the pole piece is used to increase the content of the active material. However, as the thickness of the electrode sheet increases, the active particles on the positive electrode sheet may not be able to fully function, especially when charging and discharging at a high rate, the lithium ions on the surface of the coating are often easy to deintercalate and intercalate, but the lithium ions in the deep layer On the one hand, the ions may not be completely infiltrated by the electrolyte. On the other hand, due to the increased kinetic path and resistance, it is relatively more difficult to deintercalate and intercalate between the positive and negative electrodes, and even fail to work at high magnifications.

Therefore, for thick pole pieces, the main problem is that the infiltration of the electrolyte is not complete, and the active material in the deep layer cannot fully play its role.

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