posted on 2022-12-23, 16:11authored byFengxue Duan, Shirui Jin, Yingjie Cheng, Fan Yang, Mingfeng Wei, Meiling Wang, Xu Zhang, Yongjian Yu, Xiuxiu Yin, Kangning Zhao, Yingjin Wei, Lixin Wu, Yizhan Wang
Dendrite growth and side reactions of Zn metal anodes
remain unresolved
obstacles for practical application of aqueous Zn ion batteries. Herein,
a two-dimensional (2D) organic–inorganic heterostructure with
controlled thickness was constructed as a protective layer for a Zn
metal anode. The reduction of uniformly distributed polyoxometalate
in the layer causes a negative charge density gradient, which can
accelerate zinc ion transfer, homogenize zinc deposition, and shield
sulfates at the electrode interface, while the exposed hydrophobic
alkyl chain of the layer can isolate the direct contact of water with
the Zn anode. As a result of the synergetic effect, this 2D organic–inorganic
heterostructure enables high Zn plating/stripping reversibility, with
high average Coulombic efficiencies of 99.97% for 3700 cycles at 2
mA cm–2. Under high Zn utilization conditions, a
high areal-capacity full cell with hundreds of cycles was demonstrated.