Enhanced conductivity and structure stability of BiPO4@void@C/CNT particles for high-performance bismuth-based batteries
Enhanced conductivity and structure stability of BiPO4@void@C/CNT particles for high-performance bismuth-based batteries
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用于高性能铋基电池的 BiPO4@void@C/CNT 颗粒的增强电导率和结构稳定性
DOI：
10.1039/d0dt00480d
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发表时间：
2020
影响因子：
4
通讯作者：
Zou Rujia
中科院分区：
文献类型：
--
作者：
Feng Ping;He Shu-Ang;Cui Zhe;Liu Qian;Zou Rujia
铋是下一代锂离子电池阳极的有希望的候选者;然而，在脱锂和锂化过程中Bi的不稳定结构导致循环性能差。在此，通过腐蚀和煅烧方法使用模板制备BiPO4@void@C/CNT复合材料。该复合材料具有均匀的结构，其中BiPO 4通过C/CNT中空结构内的第一放电过程转化为嵌入Li 3 PO 4基质内的Bi纳米颗粒。Li 3 PO 4基质不仅可以用作缓冲层以在插入/拔出过程中保持结构完整性，而且还提供了限制在大多数Bi纳米颗粒的表面上形成SEI层的电解质阻挡层。此外，BiPO4@void@C表面的CNT提供了互连的电子传输路径，也有效地防止了活性材料的聚集和分离。此外，中空多孔结构为Bi/Li 3 PO 4基质纳米棒的膨胀提供了足够的自由空隙。作为LIB的阳极，BiPO4@void@C/CNT在额定性能测试后，在1000 mA g− 1的高电流密度下可提供高达347.0 mA h g− 1的高容量，可保持530次循环而无容量损失。
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 BiPO4@void@C/CNT composite is prepared using a template by corrosion and calcination methods. The composite has a uniform structure, where BiPO4 is converted into Bi nanoparticles embedded within the Li3PO4 matrix by the first discharge process inside the C/CNT hollow structures. The Li3PO4 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 BiPO4@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/Li3PO4 matrix nanorods. As an anode for LIBs, BiPO4@void@C/CNT after rating performance testing delivers a high capacity of ∼347.0 mA h g−1 at a high current density of 1000 mA g−1 that is maintained for 530 cycles without capacity loss.