Stable metal anodes enabled by a labile organic molecule bonded to a reduced graphene oxide aerogel.

Gao, Yue; Wang, Daiwei; Shin, Yun Kyung; Yan, Zhifei; Han, Zhuo; Wang, Ke; Hossain, Md Jamil; Shen, Shuling et al. · Proc Natl Acad Sci U S A · 2020

basic_science · Level V

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Abstract

Metallic anodes (lithium, sodium, and zinc) are attractive for rechargeable battery technologies but are plagued by an unfavorable metal-electrolyte interface that leads to nonuniform metal deposition and an unstable solid-electrolyte interphase (SEI). Here we report the use of electrochemically labile molecules to regulate the electrochemical interface and guide even lithium deposition and a stable SEI. The molecule, benzenesulfonyl fluoride, was bonded to the surface of a reduced graphene oxide aerogel. During metal deposition, this labile molecule not only generates a metal-coordinating benzenesulfonate anion that guides homogeneous metal deposition but also contributes lithium fluoride to the SEI to improve Li surface passivation. Consequently, high-efficiency lithium deposition with a low nucleation overpotential was achieved at a high current density of 6.0 mA cm<sup>-2</sup> A Li|LiCoO<sub>2</sub> cell had a capacity retention of 85.3% after 400 cycles, and the cell also tolerated low-temperature (-10 °C) operation without additional capacity fading. This strategy was applied to sodium and zinc anodes as well.