1. Polyoxovanadate Li7[V15O36(CO3)] and its derivative γ-LiV2O5 as superior performance cathode materials for aqueous zinc-ion batteries.
- Author
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Xiao, Haoran, Du, Xin, Li, Rong, Jin, Hao, Xie, Lingling, Han, Qing, Qiu, Xuejing, Yang, Xinli, Zhu, Limin, and Cao, Xiaoyu
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CATHODES , *ENERGY storage , *ENERGY density , *POWER density , *ZINC ions , *AQUEOUS electrolytes , *ELECTROCHEMICAL electrodes - Abstract
• 1. For the first time, the Li 7 [V 15 O 36 (CO 3)] and γ -LiV 2 O 5 as host materials to store Zn2+. • 2. A larger voltage window (0.2–1.9 V) than most other aqueous zinc ion batteries. • 3. The energy density and power density of the Li 7 [V 15 O 36 (CO 3)] and the γ -LiV 2 O 5 is high. • 4. The Zn2+ storage mechanisms of the Li 7 [V 15 O 36 (CO 3)] and the γ -LiV 2 O 5 are proved. Recently, many reports have been published about polyoxovanadates (POVs) with multiple electrons redox activity for energy storage. However, they are easily transformed into solid-state oxides after calcination. We noted that although dehydrated Li 7 [V 15 O 36 (CO 3)] (Li 7 V 15) exhibited a high capacity for lithium-ion batteries (LIBs), it was reported that the electrochemical behavior of the dehydrated sample same as γ -LiV 2 O 5 (γ -LVO) which prepared by annealing the cluster and undehydrated Li 7 V 15 was not redox-active. Interestingly, we were surprised to find that undehydrated Li 7 V 15 and its derivative γ -LVO showed better electrochemical performance than LIBs when first proposed as the cathode to store Zn2+. Both Li 7 V 15 and γ -LVO electrodes provided excellent rate performance and satisfied cyclability (135.0 and 214.1 mAh g−1 at 3 A g−1 after 1000 cycles, respectively). The fast kinetics of Li 7 V 15 and γ -LVO were verified by pseudocapacitive analysis, GITT and EIS tests. Moreover, the Zn2+ storage mechanism and redox behavior of Li 7 V 15 and γ -LVO were examined by ex-situ measurements. First-principles calculations revealed that the Zn2+ was chemisorbed on the clusters and physisorbed between the clusters. This work enriches the POVs cathode chemistry in aqueous energy storage. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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