Ma Wensheng, Yu Bin, Tan Fuquan, Gao Hui, Zhang Zhonghua
Key Laboratory for Liquid-Solid Structural Evolution and Processing of Materials (Ministry of Education), School of Materials Science and Engineering, Shandong University, Jingshi Road 17923, Jinan 250061, China.
Materials (Basel). 2023 Mar 9;16(6):2189. doi: 10.3390/ma16062189.
Alloy-type anodes are the most promising candidates for sodium-ion batteries (SIBs) due to their impressive Na storage capacity and suitable voltage platform. However, the implementation of alloy-type anodes is significantly hindered by their huge volume expansion during the alloying/dealloying processes, which leads to their pulverization and detachment from current collectors for active materials and the unsatisfactory cycling performance. In this work, bimetallic Bi-Sb solid solutions in a porous carbon matrix are synthesized by a pyrolysis method as anode material for SIBs. Adjustable alloy composition, the introduction of porous carbon matrix, and nanosized bimetallic particles effectively suppress the volume change during cycling and accelerate the electrons/ions transport kinetics. The optimized BiSb@C electrode exhibits an excellent electrochemical performance with an ultralong cycle life (167.2 mAh g at 1 A g over 8000 cycles). In situ X-ray diffraction investigation is conducted to reveal the reversible and synchronous sodium storage pathway of the BiSb@C electrode: (Bi,Sb) Na(Bi,Sb) Na(Bi,Sb). Furthermore, online electrochemical mass spectrometry unveils the evolution of gas products of the BiSb@C electrode during the cell operation.
合金型阳极因其令人印象深刻的钠存储容量和合适的电压平台，是钠离子电池（SIBs）最有前景的候选材料。然而，合金型阳极在合金化/脱合金化过程中巨大的体积膨胀严重阻碍了其应用，这导致其粉化并从活性材料的集流体上脱落，以及循环性能不理想。在这项工作中，通过热解方法合成了多孔碳基体中的双金属Bi-Sb固溶体作为SIBs的阳极材料。可调节的合金组成、多孔碳基体的引入以及纳米尺寸的双金属颗粒有效地抑制了循环过程中的体积变化，并加速了电子/离子传输动力学。优化后的BiSb@C电极表现出优异的电化学性能，具有超长的循环寿命（在1 A g下8000次循环后为167.2 mAh g）。进行原位X射线衍射研究以揭示BiSb@C电极可逆且同步的钠存储途径：(Bi,Sb)→Na(Bi,Sb)→Na(Bi,Sb)。此外，在线电化学质谱揭示了BiSb@C电极在电池运行过程中气体产物的演变。
