Jump to main content
Jump to site search


Unsymmetrical fluorinated malonatoborate as an amphoteric additive for high-energy-density lithium-ion batteries

Author affiliations

Abstract

High-capacity Si-embedded anodes and Li-rich cathodes are considered key compartments for post lithium-ion batteries with high energy densities. However, the significant volume changes of Si and the irreversible phase transformation of Li-rich cathodes prevent their practical application. Here we report lithium fluoromalonato(difluoro)borate (LiFMDFB) as an unusual dual-function additive to resolve these structural instability issues of the electrodes. This molecularly engineered borate additive protects the Li-rich cathode by generating a stable cathode electrolyte interphase (CEI) while simultaneously tuning the fluoroethylene carbonate (FEC)-oriented solid electrolyte interphase (SEI) on the Si–graphite composite (SGC) anode. The complementary electrolyte design utilizing both LiFMDFB and FEC exhibited an improved capacity retention of 85%, a high Coulombic efficiency of ∼99.5%, and an excellent energy density of ∼400 W h kg−1 in Li-rich/SGC full cells at a practical mass loading after 100 cycles. This dual-function additive approach offers a way to develop electrolyte additives to build a more favorable SEI for high-capacity electrodes.

Graphical abstract: Unsymmetrical fluorinated malonatoborate as an amphoteric additive for high-energy-density lithium-ion batteries

Back to tab navigation

Supplementary files

Publication details

The article was received on 04 Feb 2018, accepted on 06 Apr 2018 and first published on 06 Apr 2018


Article type: Paper
DOI: 10.1039/C8EE00372F
Citation: Energy Environ. Sci., 2018, Advance Article
  •   Request permissions

    Unsymmetrical fluorinated malonatoborate as an amphoteric additive for high-energy-density lithium-ion batteries

    J. Han, J. B. Lee, A. Cha, T. K. Lee, W. Cho, S. Chae, S. J. Kang, S. K. Kwak, J. Cho, S. Y. Hong and N. Choi, Energy Environ. Sci., 2018, Advance Article , DOI: 10.1039/C8EE00372F

Search articles by author

Spotlight

Advertisements