摘要
Zinc-ion batteries(ZIBs) are promising alternative energy storage devices to lithium-ion batteries owing to the merits of large abundance,high theoretical capacity,and environmental friendliness.However,critical challenges including low working voltage(below 2 V),low energy density as well as dendrites formation during long cycling caused by aqueous ZIB systems still hinder their practical applications.Herein,a high-voltage Zn-graphite battery(ZGB) based on a non-zinc ion single-salt electrolyte(2.5 M LiPF6 in carbonate solvent) is developed.Moreover,we surprisingly found that Zn^(2+) is dissolved in the LiPF6 single-salt electrolyte during resting and discharging processes,thus enabling reversible Zn plating/stripping mechanism on the Zn foil anode in the ZGB over the voltage window of 1.0-3.1 V.As a result,the ZGB achieves long-term cycling performance with a capacity retention of ~100% for over1200 cycles at 3 C and high Coulombic efficiency of ~100% in 1.0-3.1 V with no dendrites formation.Moreover,the ZGB exhibits a high working voltage of up to 2.2 V,thus contributing to both high energy density(up to 210 Wh kg^(-1)) and high power density(up to 1013 W kg^(-1)),superior than most reported ZIBs.
基金
financially supported by the Key-Area Research and Development Program of Guangdong Province(2019B090914003)
the National Natural Science Foundation of China(51822210,51972329)
Shenzhen Peacock Plan(KQTD2016112915051055)
Shenzhen Science and Technology Planning Project(JCYJ20170818153404696)
Natural Science Foundation of Guangdong Province(2018A050506066)
China Postdoctoral Science Foundation(2020M672875)。