Pre-lithiation electrolyte and preparation method of pre-lithiation lithium ion battery

Abstract

The invention discloses a pre-lithiation electrolyte and a preparation method of a pre-lithiation lithium ion battery. The pre-lithiation electrolyte comprises 80 wt% of an organic solvent, 10 wt% ofa lithium salt, 1.0 wt% of a first additive, 1.0 wt% of a second additive, 0.5 wt% of a third additive and 5-10 wt% of an auxiliary reagent. The pre-lithiation electrolyte provided by the invention isapplied to the pre-lithiation battery, the process is simple and easy to operate, the condition of low initial coulombic efficiency of an existing lithium ion battery can be improved, meanwhile, thecapacity is improved, the cycle performance and the high-temperature performance of the battery are improved, and the safety of the battery can be improved. According to the technical scheme providedby the invention, when the pre-lithiation electrolyte is applied to the pre-lithiation battery, the initial efficiency of the prepared lithium ion battery is up to 98% or above, the initial reversiblecapacity is 3400 AmH or above, the capacity is kept 96% or above after 300 weeks, the high-temperature storage is kept 90% or above, and no lithium is separated out from a pole piece after circulation.

Description

technical field [0001] The invention relates to the technical field of lithium-ion batteries, in particular to a preparation method of a pre-lithiated electrolyte and a pre-lithiated lithium-ion battery. Background technique [0002] In recent years, with the increasing demand for lithium-ion batteries in electronic products and electric vehicles, lithium-ion batteries have developed rapidly, and the requirements for high energy density and high power of batteries are also increasing. However, the improvement of the energy density of lithium-ion batteries has reached or approached the limit value of existing electrode materials. In addition, lithium-ion batteries have the problem of initial capacity loss during the first charge and discharge process. In view of this, the researchers proposed a pre-lithiation technology for lithium-ion batteries. [0003] Lithium-ion batteries mainly rely on lithium ions to shuttle between positive and negative electrode materials to achieve...

AI Technical Summary

Problems solved by technology

However, for a long time, lithium-ion batteries prepared by various pre-lithiation methods have the following problems: poor high-temperature performance, and lithium dendrites are easily formed during charging, which affects the safety performance of the battery.

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