Polyvinylpyrrolidone regulated synthesis of mesoporous titanium niobium oxide as high-performance anode for lithium-ion batteries

Autor: Yan Liu, Hongkang Wang, Yonghong Cheng, Menglong Yao, Huiying Lu, Tianhao Yao, Ruifeng Qian, Jian-Wen Shi, Fengping Xiao
Rok vydání: 2022
Předmět:
Zdroj: Journal of Colloid and Interface Science. 608:1782-1791
ISSN: 0021-9797
DOI: 10.1016/j.jcis.2021.10.073
Popis: TiNb2O7 (TNO) as a promising candidate anode for lithium-ion batteries (LIBs) shows obvious advantages in terms of specific capacity and safety, but which undergoes the intrinsic poor electrical and ionic conductivity. Herein, we propose a simple synthesis strategy of mesoporous TNO via a polymeric surfactant-mediated evaporation-induced sol-gel method, using polyvinylpyrrolidone (PVP) with different molecular weights (average Mw: 10000/58000/1300000) as the regulating agent, which greatly affects the lithium storage performance of the as-prepared TNO. The optimized TNO (i.e., PVP of 58000) delivers a high reversible capacity of 303.1 mAh/g at 1 C, with a retention rate of 73.4% (222.5 mAh/g) after 300 cycles. Even at 5 C, a high reversible capacity of 185.6 mAh/g can be achieved, with a retention rate of 72.3% after 1000 cycles. The superior lithium storage behavior is attributed to the fine mesoporous framework consisting of interconnected TNO nanocrystallites with high specific surface area and high mesoporosity, which greatly increases the active sites, improves the Li+ diffusion kinetics and alleviates volume fluctuation induced by the repetitive Li+ insertion-extraction processes.
Databáze: OpenAIRE
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