Issue 9, 2020

Origin of extra capacity in the solid electrolyte interphase near high-capacity iron carbide anodes for Li ion batteries

Abstract

Transition metal carbides (TMCs), known to deliver extra capacity beyond the theoretical limit, are proposed as emerging high-capacity anodes for next-generation lithium ion batteries (LIBs). Nevertheless, the underlying mechanism for the extra lithium storage in TMCs has not been revealed clearly due to the electrochemical inertness of TMCs to Li in cycling. Here, for the first time, by employing in situ Raman and X-ray photoelectron spectroscopies, we corroborate that the capacity enhancement of Fe3C anodes originates from the physiochemical evolution of solid electrolyte interphase (SEI) and surface carbonaceous materials through three mechanisms: (i) Fe3C catalyzes the reversible conversion between esters and ethers to store extra lithium ions in the SEI; (ii) Fe and inorganic components embedded in the SEI form a reversible surface-conversion reaction of Fe + 3LiF ⇌ FeF3 + 3Li+ + 3e to contribute additional capacity; and (iii) surficial carbon delivers capacity through surface capacitive effects and Li+ inter/deintercalation processes. With the extra lithium ion storage in the SEI and carbon, the C@Fe3C/Fe anode delivers a high reversible capacity of 808 mA h g−1 after 700 cycles at 1 A g−1. This study provides a fundamental basis for emerging high-capacity TMC anodes to be efficiently explored for next-generation LIBs.

Graphical abstract: Origin of extra capacity in the solid electrolyte interphase near high-capacity iron carbide anodes for Li ion batteries

Supplementary files

Article information

Article type
Paper
Submitted
17 Dec. 2019
Accepted
14 Maijs 2020
First published
14 Maijs 2020

Energy Environ. Sci., 2020,13, 2924-2937

Origin of extra capacity in the solid electrolyte interphase near high-capacity iron carbide anodes for Li ion batteries

D. Chen, C. Feng, Y. Han, B. Yu, W. Chen, Z. Zhou, N. Chen, J. B. Goodenough and W. He, Energy Environ. Sci., 2020, 13, 2924 DOI: 10.1039/C9EE04062E

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements