摘要
Magnesium ion batteries are emerging as promising alternatives to lithium ion batteries because of their advantages including high energydensity,dendrite-free features and low cost.Nevertheless,one of the major challenges for magnesium ion batteries is the kinetically sluggishmagnesium insertion/extraction and diffusion in electrode materials.Aiming at this issue,biphase eutectic-like bismuth-tin film is designedherein to construct a self-supporting anode with interdigitated phase distribution and hierarchically porous structure,and further fabricated bya facile one-step magnetron cosputtering route.As benchmarked with single-phase bismuth or tin film,the biphase bismuth-tin film delivershigh specific capacity (538 mAh/g at 50 mA/g),excellent rate performance (417 mAh/g at 1,000 mA/g) and good cycling stability (233 mAh/gat the 200th cycle).The superior magnesium storage performance of the sputtered bismuth-tin film could be attributed to the synergetic effectof the interdigitated bismuth/tin phase distribution,hierarchically porous structure and biphase buffering matrices,which could increase ionictransport channels,shorten diffusion lengths and reduce total volume changes.
基金
National Natural Science Foundation of China (Nos. 51671115 and 51871133)
Department of Science and Technology of Shandong Province for Young Tip-top Talent Support Project
Young Tip-top Talent Support Project (the Organization Department of the Central Committee of the CPC).