Liu Yuhan, Li Malin, Zheng Yingying, Lin Hezhe, Wang Ziyang, Xin Wen, Wang Chunzhong, Du Fei
Key Laboratory of Physics and Technology for Advanced Batteries (Ministry of Education), College of Physics, Jilin University, Changchun 130012, P. R. China.
Nanoscale. 2020 Dec 23;12(48):24394-24402. doi: 10.1039/d0nr06457b.
Potassium-ion batteries (PIBs) are considered a promising alternative to lithium-ion batteries (LIBs) for next-generation energy storage due to the abundance and competitive cost of potassium resources. However, the excavation and the development of proper electrodes for PIBs are still confronted with great challenges. Herein, a self-assembled bismuth sulfide microsphere wrapped with reduced graphene oxide was fabricated to form a heterostructured Bi2S3@RGO composite via a visible-light-assisted method and served as the anode for PIBs. The as-prepared Bi2S3@RGO composite presented a high reversible specific capacity of 538 mA h g-1 at 0.2 A g-1 and superior rate capability of 237 mA h g-1 at a high current density of 2 A g-1 after 300 cycles. In particular, the high capacity could be ascribed to the synergistic effect of the conversion and alloying reactions during the electrochemical processes, which was validated by ex situ X-ray diffraction. The fabrication of a unique heterostructure combining the self-assembled Bi2S3 microspheres and flexible RGO boosted the facile charge transfer, leading to the enhanced cyclic stability and rate performance.
由于钾资源丰富且成本具有竞争力，钾离子电池（PIBs）被认为是下一代储能领域锂离子电池（LIBs）的一种有前景的替代方案。然而，用于PIBs的合适电极的挖掘和开发仍面临巨大挑战。在此，通过可见光辅助方法制备了一种包裹有还原氧化石墨烯的自组装硫化铋微球，以形成异质结构的Bi2S3@RGO复合材料，并用作PIBs的阳极。所制备的Bi2S3@RGO复合材料在0.2 A g-1下呈现出538 mA h g-1的高可逆比容量，在2 A g-1的高电流密度下经过300次循环后具有237 mA h g-1的优异倍率性能。特别是，高容量可归因于电化学过程中转化和合金化反应的协同效应，这通过非原位X射线衍射得到了验证。将自组装的Bi2S3微球与柔性RGO相结合的独特异质结构的构建促进了电荷的轻松转移，从而提高了循环稳定性和倍率性能。
