Recently, Junwei Zhao group published a new paper in Energy Storage Materials, the title is “Stable aqueous Zn−Ag and Zn−polyoxometalate hybrid battery driven by successive Ag+ cation and polyoxoanion redox reactions”. In this paper, the authorsuggeststhatHybrid batteries with multiple electrochemical reactions that integrate respective advantages and remedy intricate shortages of disparate batteries are both fundamentally interesting and practically attractive. Here, an aqueous hybrid battery combining electrochemical features of Zn−Ag battery and Zn−POM battery is for the first time proposed, which is actuated by successive Ag⁺cation and polyoxoanion redox reactions in an insoluble polyoxometalate (POM)-based cathode. The unique POM-based composite material constructed from loose stacking high-nuclearity polyoxovanadate clusters and crystalline Ag nanoparticles not only provides plentiful Zn²⁺storage sites but also presents fast ion / electron diffusion kinetics. Meanwhile, both the severe migration of Ag⁺ions and the dissolution of POM clusters in aqueous electrolyte are effectively inhibited. The as-fabricated hybrid battery with POM-based cathode exhibits a reversible capacity of 200 mAh g^–1at 10 A g^–1with outstanding capacity retention (97.4% over 7000 cycles) and superior rate capability. Moreover, the stable hybrid energy storage mechanism is revealed in detail. The work presents a promising strategy for the application of POM-based electrode in aqueous batteries and provides heuristic thinking for further developing novel energy storage systems.

This article was published online by Energy Storage Materials on Sep. 21, 2020, (DOI: 10.1016/j.ensm.2020.09.011). Junwei Zhao and Yuanyuuan Hu atCollege of Chemistry and Chemical Engineering, Henan University arethe corresponding author of this article. The first author is Kai Yang.

This work was financially supported by the National Natural Science Foundation of China, the Program for Innovation Teams in Science and Technology in Universities of Henan Province, China Postdoctoral Science Foundation, the Major Project of Science and Technology, Education Department of Henan Province, the Program of First-Class Discipline Cultivation Project of Henan University and the 2019 Students Innovative Pilot Plan of Henan University.