Coiled lithium-ion battery pole piece

Abstract

The invention discloses a coiled lithium-ion battery positive and negative pole piece, which comprises a positive pole piece and a negative pole piece, wherein the positive pole piece is provided witha positive pole lug position and a folding-proof position, and the positive pole piece is coated with a first active substance at all positions except for the positive lug position and the folding-proof position; and the negative pole piece is provided with a negative pole lug position and a blank position, and the negative pole piece is coated with a second active substance at all positions except for the negative pole lug position and the blank position. The invention has the beneficial effects that the coiled lithium-ion battery pole piece avoids the problem that the existing design positive pole piece does not have a corresponding negative pole piece for lithium precipitation, the safety the improved, the unit volume capacity of the battery is increased, the consumption of a negativeelectrode material can also be reduced, the utilization of positive and negative materials is maximized, the utilization of raw materials can be maximized, and the energy density in the limited volumeis the highest.

Description

technical field [0001] The invention relates to a positive and negative electrode sheet of a winding type lithium ion battery, belonging to the technical field of new energy lithium ion batteries. Background technique [0002] Lithium-ion battery is currently recognized by the world industry as the battery system with the best comprehensive performance. Its advantages can basically be summarized as follows: high working voltage, large specific energy, small size, light weight, long cycle life, low self-discharge rate, no memory Effect, green environmental protection, etc. [0003] How to achieve both high safety and high energy density of lithium-ion batteries is the top priority at present. There are two main structures of batteries, stacked and wound; the two structures have their own advantages, but the winding process is simpler Easy to operate, easy to realize industrial automation. At present, most enterprises in the market adopt the winding form. The winding type i...

AI Technical Summary

Problems solved by technology

like Figure 5 As shown, the positive or negative electrodes of the current winding structure are convenient for winding and quick coating of active materials, and in order to avoid spontaneous combustion caused by contact short circuit of the active materials on the positive and negative electrodes when the positive and negative electrodes are wound, and in order to avoid spontaneous combustion. The curvature of the first half of the winding is too small, causing the problem of stress concentration and shedding of the surface coating. When designing, the first or half of the winding is not coated, usually with a length of 20-150mm, and the negative electrode tail is coated on both sides. When discharging, the lithium ions from the positive electrode must correspond to the negative electrode. The current structure design of the positive electrode part has no corresponding negative electrode sheet during winding, which is likely to cause safety hazards and reduce the energy density of the battery. The single-sided and double-sided coating on the negative electrode tail causes surface activity Material waste, resulting in waste of materials and increased costs

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