Feng Ping, He Shu-Ang, Cui Zhe, Liu Qian, Zou Rujia
State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, Department of Physics, College of Science, Donghua University, Shanghai 201620, China.
Dalton Trans. 2020 May 7;49(17):5636-5645. doi: 10.1039/d0dt00480d. Epub 2020 Apr 14.
Bismuth is a promising candidate for next generation lithium-ion battery anodes; however, the unstable structure of Bi during delithiation and lithiation processes leads to poor cycling performance. Here, a BiPO@void@C/CNT composite is prepared using a template by corrosion and calcination methods. The composite has a uniform structure, where BiPO is converted into Bi nanoparticles embedded within the LiPO matrix by the first discharge process inside the C/CNT hollow structures. The LiPO matrix can not only serve as a buffer layer to maintain the structural integrity during insertion/extraction processes, but also provides an electrolyte-blocking layer that limits the formation of the SEI layer on the surfaces of most of the Bi nanoparticles. Moreover, the CNTs on the surface of BiPO@void@C offer an interconnected electron transportation pathway and also effectively prevent aggregation and separation of the active materials. In addition, the hollow porous structure provides sufficient free voids for expansion of the Bi/LiPO matrix nanorods. As an anode for LIBs, BiPO@void@C/CNT after rating performance testing delivers a high capacity of ∼347.0 mA h g at a high current density of 1000 mA g that is maintained for 530 cycles without capacity loss.
