5V LNMO-based lithium-ion batteries multifunctional electrolyte additive—lithium bioxalatodifluorophosphate(LiBODFP)

Lithium-ion batteries are widely used in digital products, new energy vehicles and energy storage, because of their small size, convenient carrying and large charge capacity. With the widespread use of lithium-ion batteries, their performance requirements are also increasing. In order to improve the cycle performance, high and low temperature performance, safety performance, etc. of existing lithium ion batteries, electrolyte additives are a relatively economical and effective method. Below we will introduce a multifunctional additive for the high-voltage lithium-ion battery - Lithium bisoxalatodifluorophosphate (LiBODFP).

Yang et al published an article in Journal of Materials chemistry A show that LiBODFP is a promising multifunctional lithium salt-type electrolyte additive used to enhance the performance of 5 V LiNi_0.5Mn_1.5O₄ (LNMO)-based lithium-ion batteries (LIBs). Compared to cells without the additive, the cycling retention of the LNMO/Li half cells with 1.0% LiBODFP was improved from 77.6% to 93.7% at a 1C rate after 300 cycles. The capacity retention of the high voltage LNMO/graphite full cells with LiBODFP reached 82% at a 0.5C rate after 100 cycles, which was much higher than that of the cells without the additive (50%). It is shown that the LiBODFP can be preferentially oxidized and reduced to form robust interface films with low resistance and high conductivity on the surfaces of LNMO cathodes and graphite anodes, respectively. The LiBODFP-derived interface film can protect the cathode and anode materials, alleviate the decomposition of the electrolyte, and prevent the dissolution of metal ions from the LNMO cathode and their deposition on the graphite surface. This work provides an effective strategy for developing a functional electrolyte that matches the requirement of LNMO-based batteries with a high-voltage window and enhanced performance.

The lithium-ion battery electrolyte additive has the characteristics of less added amount and significantly improved battery performance, and is a practical and effective strategy for effectively solving the current lithium battery application problem.

References:

  T. Yang, H. Zeng, W. Wang, X. Zhao, W. Fan, C. Wang, X. Zuo, R. Zeng and J. Nan, J. Mater. Chem. A, 2019, DOI:10.1039/ C9TA01293A.

Related links: Lithium bisoxalatodifluorophosphate

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