Duan K, Ning J, Zhou L, Wang S, Wang Q, Liu J, Guo Z. Synergistic Inorganic-Organic Dual-Additive Electrolytes Enable Practical High-Voltage Lithium-Ion Batteries.
ACS APPLIED MATERIALS & INTERFACES 2022;
14:10447-10456. [PMID:
35179877 DOI:
10.1021/acsami.1c24808]
[Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Severe electrolyte decomposition under high voltage can easily lead to degradation of the performance of lithium-ion batteries, which has become a major obstacle to the practical application of high-energy-density batteries. To solve these problems, a dual-functional electrolyte additive comprising inorganic lithium difluorophosphate (LiDFP) and organic 1,3,6-hexanetrinitrile (HTN) was designed and employed to improve the performance of high-voltage Si@C/LiNi0.5Mn1.5O4 full batteries. LiDFP with a lower LUMO energy than the solvent in the electrolyte takes priority in reduction, facilitating the formation of a dense and stable film on the anode, effectively suppressing side reactions of the electrolyte and aiding tolerance to the volume expansion of the Si@C electrode. Additionally, the lower HOMO energy of HTN can improve the oxidation resistance of the electrolyte, with the C≡N functional group of HTN helping to remove the trace water and the byproduct HF from the electrolyte. The Si@C/LiNi0.5Mn1.5O4 full battery with 1 wt % LiDFP and 1 wt % HTN in 1.0 M LiPF6 traditional electrolyte delivers high capacity retention of 91.57% after 150 cycles at 0.2C, compared to 34.58% capacity retention without any additives. Moreover, the Coulombic efficiency of batteries with electrolyte additives can reach 99.75% on average, compared to their counterparts at ∼96.54%. The synergistic effect of LiDFP and HTN provides a promising strategy for enhancing the performance of high-voltage batteries for practical industrialization.
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