2026-04-17T07:54:33Zhttps://recercat.cat/oai/request

oai:recercat.cat:2117/3829692026-01-21T10:10:06Zcom_2072_1033col_2072_452950

00925njm 22002777a 4500 dc Yang, Dawei author Li, Mengyao author Zheng, Xuejiao author Han, Xu author Zhang, Chaoqi author Jacas Biendicho, Jordi author Llorca Piqué, Jordi author Wang, Jiaao author Hao, Hongchang author Li, Junshan author Henkelman, Graeme author Arbiol, Jordi author Morante, Joan Ramon author Mitlin, David author Chou, Shu-Lei author Cabot, Andreu author 2022-06-27 The shuttling of soluble lithium polysulfides (LiPS) and the sluggish Li–S conversion kinetics are two main barriers toward the practical application of lithium–sulfur batteries (LSBs). Herein, we propose the addition of copper selenide nanoparticles at the cathode to trap LiPS and accelerate the Li–S reaction kinetics. Using both computational and experimental results, we demonstrate the crystal phase and concentration of copper vacancies to control the electronic structure of the copper selenide, its affinity toward LiPS chemisorption, and its electrical conductivity. The adjustment of the defect density also allows for tuning the electrochemically active sites for the catalytic conversion of polysulfide. The optimized S/Cu1.8Se cathode efficiently promotes and stabilizes the sulfur electrochemistry, thus improving significantly the LSB performance, including an outstanding cyclability over 1000 cycles at 3 C with a capacity fading rate of just 0.029% per cycle, a superb rate capability up to 5 C, and a high areal capacity of 6.07 mAh cm–2 under high sulfur loading. Overall, the present work proposes a crystal phase and defect engineering strategy toward fast and durable sulfur electrochemistry, demonstrating great potential in developing practical LSBs. Peer Reviewed Postprint (author's final draft) Àrees temàtiques de la UPC::Enginyeria química Copper selenide Phase engineering Copper vacancies Lithium-sulfur battery Lithium polysulfide Phase engineering of defective copper selenide toward robust lithium-sulfur batteries