High-energy density ferrous phosphate lithium battery electrolyte and lithium ion battery

Abstract

The invention discloses a high-energy density ferrous phosphate lithium battery electrolyte and a lithium ion battery and belongs to the technical field of lithium ion batteries. The high-energy density ferrous phosphate lithium battery electrolyte of the present invention comprises a nonaqueous organic solvent, lithium salt and additives, wherein the additives comprise three kinds of additives, namely an A additive, a B additive and a C additive; the structural formula of the additive A is M which is described in the descriptions of the invention; the additive B is a compound of which the structural formula is N or O which is described in the descriptions of the invention; and the additive C is a type of sulfur-containing ring organic compound. According to the electrolyte of the invention, the A additive, the B additive and the C additive are used in a combined manner, so that organic and inorganic compositions in an SEI film are relatively balanced; a battery pole sheet interface isoptimized; the physical and chemical stability of the SEI film is enhanced; the performance requirements of a lithium iron phosphate system high-energy density battery can be satisfied; and the balance of comprehensive performance under a high-energy density condition can be realized.

Description

technical field [0001] The invention relates to the field of batteries, in particular to a high-energy-density lithium ferrous phosphate battery electrolyte and a lithium-ion battery. Background technique [0002] Lithium iron phosphate (LiFePO 4 ) is currently one of the most promising positive electrode materials in the field of power batteries and energy storage due to the advantages of cheap price, good safety performance, non-toxicity, environmental friendliness, and theoretical capacity up to 170mAh / g. However, the compaction density of the traditional lithium iron phosphate battery system is low, and the energy density has become a major obstacle limiting its development. [0003] In order to improve the energy density of the iron-lithium battery system, the following methods are mainly adopted in terms of materials and design: ① Nano-scale the iron-lithium material on the positive electrode, increase the coating surface density of the positive electrode material, an...

AI Technical Summary

Problems solved by technology

[0007] To sum up, the current lithium iron battery electrolyte cannot meet the demand for high energy density, especially when the negative electrode is a high-pressure graphite negative electrode or a negative electrode material doped with a certain proportion of silicon

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