Negative electrode sheet and lithium ion battery

Abstract

This invention discloses a negative electrode sheet and a lithium-ion battery. The negative electrode sheet includes at least two sets of active units coated sequentially from one side of a negative electrode current collector. Each set of active units includes a graphite negative electrode layer and a hard carbon negative electrode layer coated sequentially from the inside out. The graphite negative electrode layer has multiple pores spaced apart on the side adjacent to the hard carbon negative electrode layer, and hard carbon negative electrode material for forming the hard carbon negative electrode layer is embedded within these pores. The pore capacity between each set of active units increases sequentially from the inside out. This invention, by optimizing the negative electrode sheet structure, can significantly improve the low-temperature charge-discharge cycle performance of the battery. This multi-layer negative electrode sheet has the advantages of high charging efficiency and strong low-temperature charge-discharge capability, which can significantly improve the high-rate charge-discharge performance of lithium-ion batteries and extend the electrode life under high-rate charge-discharge conditions.

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