Title

Investigation of gas evolution from Li4Ti5O12 anode for lithium ion batteries

Document Type

Article

Date of Original Version

1-1-2018

Abstract

Lithium titanate (LTO) has been investigated as one of the leading anode materials for lithium ion batteries in grid storage and automotive applications. However, one of the primary challenges is cell gassing which can significantly limit life of cells despite the excellent lifetime performance of LTO anodes. Gas evolution has been previously attributed to water impurities from the electrolyte, moisture trapped in the electrode, the breakdown of lithium salt forming hydrofluoric acid (HF), and/or solvent reactions with the surface of the electrode. The role of electrolyte in gas evolution has been investigated during formation, high temperature storage, and high temperature cycling. The effect of LiTFSI, LiFSI, EC-free formulations, and a novel LTO electrolyte additive (tris (trimethysilyl) borate) have been investigated. Incorporation of an EC free electrolyte or a novel electrolyte additive result in a significant reduction in gas generation. Analysis of the gas composition suggests that the majority of the gas results from solvent reactions with the LTO surface while the reactions of the residual water are a secondary source of gassing.

Publication Title

Journal of the Electrochemical Society

Volume

165

Issue

13

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