Zhang Shipeng, Ling Fangxin, Wang Lifeng, Xu Rui, Ma Mingze, Cheng Xiaolong, Bai Ruilin, Shao Yu, Huang Huijuan, Li Dongjun, Jiang Yu, Rui Xianhong, Bai Jintao, Yao Yu, Yu Yan
Hefei National Laboratory for Physical Sciences at the Microscale, Department of Materials Science and Engineering, CAS Key Laboratory of Materials for Energy Conversion, University of Science and Technology of China, Hefei, Anhui, 230026, P. R. China.
State Key Laboratory of Photon-Technology in Western China Energy, International Collaborative Center on Photoelectric Technology and Nano Functional Materials, Institute of Photonics & Photon-Technology, Northwest University, Xi'an, 710127, P. R. China.
Adv Mater. 2022 May;34(18):e2201420. doi: 10.1002/adma.202201420. Epub 2022 Mar 28.
Sulfides are perceived as promising anode materials for potassium-ion batteries (PIBs) due to their high theoretical specific capacity and structural diversity. Nonetheless, the poor structural stability and sluggish kinetics of sulfides lead to unsatisfactory electrochemical performance. Herein, Ni S -Co S heterostructures with an open-ended nanocage structure wrapped by reduced graphene oxide (Ni-Co-S@rGO cages) are well designed as the anode for PIBs via a selective etching and one-step sulfuration approach. The hollow Ni-Co-S@rGO nanocages, with large surface area, abundant heterointerfaces, and unique open-ended nanocage structure, can reduce the K diffusion length and promote reaction kinetics. When used as the anode for PIBs, the Ni-Co-S@rGO exhibits high reversible capacity and low capacity degradation (0.0089% per cycle over 2000 cycles at 10 A g ). A potassium-ion full battery with a Ni-Co-S@rGO anode and Prussian blue cathode can display a superior reversible capacity of 400 mAh g after 300 cycles at 2 A g . The unique structural advantages and electrochemical reaction mechanisms of the Ni-Co-S@rGO are revealed by finite-element-simulation in situ characterizations. The universal synthesis technology of bimetallic sulfide anodes for advanced PIBs may provide vital guidance to design high-performance energy-storage materials.
硫化物因其高理论比容量和结构多样性，被视为钾离子电池（PIB）颇具前景的负极材料。然而，硫化物较差的结构稳定性和缓慢的动力学导致其电化学性能不尽人意。在此，通过选择性蚀刻和一步硫化法，精心设计了一种具有开放式纳米笼结构且被还原氧化石墨烯包裹的Ni S -Co S异质结构（Ni-Co-S@rGO笼）作为PIB的负极。中空的Ni-Co-S@rGO纳米笼具有大表面积、丰富的异质界面和独特的开放式纳米笼结构，可缩短钾离子扩散长度并促进反应动力学。当用作PIB的负极时，Ni-Co-S@rGO表现出高可逆容量和低容量衰减（在10 A g 下2000次循环中每次循环容量衰减0.0089%）。采用Ni-Co-S@rGO负极和普鲁士蓝正极的钾离子全电池在2 A g 下300次循环后可展现出400 mAh g 的优异可逆容量。通过有限元模拟原位表征揭示了Ni-Co-S@rGO独特的结构优势和电化学反应机理。先进PIB双金属硫化物负极的通用合成技术可能为设计高性能储能材料提供重要指导。
