title: A Chemical-Adsorption Strategy to Enhance the Reaction Kinetics of Lithium-Rich Layered Cathodes via Double-Shell Surface Modification.
abstract: Sluggish surface reaction kinetics hinders the power density of Li-ion battery. Thus, various surface modification techniques have been applied to enhance the electronic/ionic transfer kinetics. However, it is challenging to obtain a continuous and uniform surface modification layer on the prime particles with structure integration at the interface. Instead of classic physical-adsorption/deposition techniques, we propose a novel chemical-adsorption strategy to synthesize double-shell modified lithium-rich layered cathodes with enhanced mass transfer kinetics. On the basis of experimental measurement and first-principles calculation, MoO2S2 ions are proved to joint the layered phase via chemical bonding. Specifically, the Mo-O or Mo-S bonds can flexibly rotate to bond with the cations in the layered phase, leading to the good compatibility between the thiomolybdate adsorption layer and layered cathode. Followed by annealing treatment, the lithium-excess-spinel inner shell forms under the thiomolybdate adsorption layer and functions as favorable pathways for lithium and electron. Meanwhile, the nanothick MoO3-x(SO4)x outer shell protects the transition metal from dissolution and restrains electrolyte decomposition. The double-shell modified sample delivers an enhanced discharge capacity almost twice as much as that of the unmodified one at 1 A g(-1) after 100 cycles, demonstrating the superiority of the surface modification based on chemical adsorption.
authors: School of Materials Science and Engineering and Tianjin Key Laboratory of Composites and Functional Materials, Tianjin University , Tianjin 300072, China.
authors: Lichao
authors: L
authors: Guo
authors: School of Materials Science and Engineering and Tianjin Key Laboratory of Composites and Functional Materials, Tianjin University , Tianjin 300072, China.
authors: Jiajun
authors: J
authors: Li
authors: School of Materials Science and Engineering and Tianjin Key Laboratory of Composites and Functional Materials, Tianjin University , Tianjin 300072, China.
authors: Tingting
authors: T
authors: Cao
authors: School of Materials Science and Engineering and Tianjin Key Laboratory of Composites and Functional Materials, Tianjin University , Tianjin 300072, China.
authors: Huayu
authors: H
authors: Wang
authors: School of Materials Science and Engineering and Tianjin Key Laboratory of Composites and Functional Materials, Tianjin University , Tianjin 300072, China.|Collaborative Innovation Center of Chemical Science and Engineering , Tianjin 300072, China.
authors: Naiqin
authors: N
authors: Zhao
authors: School of Materials Science and Engineering and Tianjin Key Laboratory of Composites and Functional Materials, Tianjin University , Tianjin 300072, China.
authors: Fang
authors: F
authors: He
authors: School of Materials Science and Engineering and Tianjin Key Laboratory of Composites and Functional Materials, Tianjin University , Tianjin 300072, China.
authors: Chunsheng
authors: C
authors: Shi
authors: School of Materials Science and Engineering and Tianjin Key Laboratory of Composites and Functional Materials, Tianjin University , Tianjin 300072, China.
authors: Chunnian
authors: C
authors: He
authors: School of Materials Science and Engineering and Tianjin Key Laboratory of Composites and Functional Materials, Tianjin University , Tianjin 300072, China.|Collaborative Innovation Center of Chemical Science and Engineering , Tianjin 300072, China.
authors: Enzuo
authors: E
authors: Liu
keywords: DFT calculations; chemical-adsorption; double shell; lithium rich layered cathode; surface modification