Cu4SnS4-Rich Nanomaterials for Thin-Film Lithium Batteries with Enhanced Conversion Reaction

Jie Lin; Jin-Myoung Lim; Duck Hyun Youn; Yang Liu; Yuxin Cai; Kenta Kawashima; Jun-Hyuk Kim; Dong-Liang Peng; Hang Guo; Graeme Henkelman; Adam Heller; C Buddie Mullins

doi:10.1021/acsnano.9b05029

Cu₄SnS₄-Rich Nanomaterials for Thin-Film Lithium Batteries with Enhanced Conversion Reaction

ACS Nano. 2019 Sep 24;13(9):10671-10681. doi: 10.1021/acsnano.9b05029. Epub 2019 Sep 3.

Authors

Jie Lin, Jin-Myoung Lim¹, Duck Hyun Youn², Yang Liu³, Yuxin Cai, Kenta Kawashima, Jun-Hyuk Kim⁴, Dong-Liang Peng, Hang Guo, Graeme Henkelman, Adam Heller, C Buddie Mullins

Affiliations

¹ Department of Materials Science and Engineering , Northwestern University , Evanston , Illinois 60208 , United States.
² Department of Chemical Engineering , Kangwon National University , Chuncheon , Gangwon-do 24341 , South Korea.
³ College of Chemistry and Chemical Engineering , Central South University , Changsha , Hunan 410083 , China.
⁴ Analysis and Assessment Group , Research Institute of Industrial Science & Technology , Pohang 37673 , South Korea.

PMID: 31449392
DOI: 10.1021/acsnano.9b05029

Abstract

Through a simple gelation-solvothermal method with graphene oxide as the additive, a Cu₄SnS₄-rich composite of nanoparticles and nanotubes is synthesized and applied for thin and flexible Li-metal batteries. Unlike the Cu₂SnS₃-rich electrode, the Cu₄SnS₄-rich electrode cycles stably with an enhanced conversion capacity of ∼416 mAh g^-1 (∼52% of total capacity) after 200 cycles. The lithiation/delithiation mechanisms of Cu-Sn-S electrodes and the voltage ranges of conversion and alloying reactions are informed by in situ X-ray diffraction tests. The conversion process of three Cu-Sn-S compounds is compared by density functional theory (DFT) calculations based on three algorithms, elucidating the enhanced conversion stability and superior diffusion kinetics of Cu₄SnS₄ electrodes. The reaction pathway of Cu-Sn-S electrodes and the root cause for the unstable capacity are revealed by in situ/ex situ characterizations, DFT calculations, and various electrochemical tests. This work provides insight into developing energy materials and power devices based on multiple lithiation mechanisms.

Keywords: copper tin sulfide; density functional theory; diffusion kinetic; gelation−solvothermal; in situ X-ray diffraction; thin-film lithium battery.