A Peapod-like CoP@C Nanostructure from Phosphorization in a Low-Temperature Molten Salt for High-Performance Lithium-Ion Batteries

Zhiliang Liu; Sungjin Yang; Bingxue Sun; Xinghua Chang; Jie Zheng; Xingguo Li

doi:10.1002/anie.201805468

A Peapod-like CoP@C Nanostructure from Phosphorization in a Low-Temperature Molten Salt for High-Performance Lithium-Ion Batteries

Angew Chem Int Ed Engl. 2018 Aug 6;57(32):10187-10191. doi: 10.1002/anie.201805468. Epub 2018 Jul 13.

Authors

Zhiliang Liu¹, Sungjin Yang¹, Bingxue Sun¹, Xinghua Chang^{1

2}, Jie Zheng¹, Xingguo Li¹

Affiliations

¹ Beijing National Laboratory for Molecular Sciences (BNLMS), The State Key Laboratory of Rare Earth Materials Chemistry and Applications, College of Chemistry and Molecular Engineering, Peking University, Beijing, 100871, China.
² Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, 100871, China.

PMID: 29920895
DOI: 10.1002/anie.201805468

Abstract

A mild phosphorization process in low-temperature molten salt (NaCl-KCl-AlCl₃ ) has been developed to synthesize peapod-like CoP@C nanostructures by using low-toxicity industrial PCl₃ as the phosphorus source and Mg as the reductant at 250 °C. Importantly, high efficiency of the phosphorous source is achieved since only stoichiometric PCl₃ is required to complete the reaction. The molten NaCl-KCl-AlCl₃ not only provides a liquid environment but also participates in the electron transport by the reversible conversion of the Al³⁺ /Al redox couple. The obtained 0D-in-1D peapod CoP@C structure exhibits excellent lithium storage performance, delivering a superiorly stable capacity of 500 mAh g^-1 after 800 cycles at a high current of 1.0 A g^-1 .

Keywords: cobalt; lithium-ion batteries; low-temperature molten salts; magnesium; transition-metal phosphides.