Lithium ion battery non-aqueous electrolyte and lithium ion battery

Abstract

The invention relates to a lithium ion battery non-aqueous electrolyte and a lithium ion battery. The non-aqueous electrolyte comprises an organic solvent, a lithium salt and an additive, and the additive comprises 0.1-2 wt% of 1, 2, 3-trifluoro-benzene based on the weight of the non-aqueous electrolyte. The 1, 2, 3-trifluoro-benzene is added into the electrolyte as an additive to effectively improve the compatibility of the electrolyte with the pole piece and improve the permeability of the electrolyte on the pole piece; and the 1, 2, 3-trifluoro-benzene has a positive electrode film formation effect to protect the positive electrode so as to improve the high-temperature storage performance and the cycle performance.

Description

technical field [0001] The invention relates to the field of electrochemistry, in particular to a lithium-ion battery non-aqueous electrolyte and a lithium-ion battery. Background technique [0002] Lithium-ion batteries are currently the most popular and widely used secondary batteries because of their excellent electrochemical performance, safety and environmental protection. With the continuous improvement of the cruising range of new energy vehicles and the continuous development of thinner and lighter 3C digital products, the battery industry is increasingly demanding high energy density of lithium-ion batteries. At present, high energy density is mainly achieved through two ways, that is, to adopt high-capacity positive electrodes and high-capacity negative electrodes. At present, the relatively mature high-capacity positive electrodes are mainly high-voltage lithium cobalt oxide materials, such as the mature 4.35V and soon-to-be-mature high-voltage lithium cobalt oxi...

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Problems solved by technology

[0008] The fluorobenzene compounds added in the above-mentioned patents improve the permeability of the electrolyte to a certain extent, increase the battery capacity, improve the charge-discharge cycle performance and high-low temperature storage performance of the battery, but the improvement effect is limited, and for compaction Density at 1.65g / cm 3 For the above graphite negative electrode materials, the improvement of the permeability of the electrolyte is not obvious. Therefore, it is necessary to seek a method that can significantly improve the permeability of the electrolyte, especially when the compacted density of the negative electrode is 1.65g / cm 3 The electrolyte additives with permeability in the above battery system have become a major technical problem to be solved urgently by those skilled in the art.

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