Tuning Zn^(2+) coordination tunnel by hierarchical gel electrolyte for dendrite-free zinc anode  

分级凝胶电解质调控Zn^(2+)配位隧道助力无枝晶锌负极

作　　者：Bingyao Zhang Liping Qin Yun Fang Yizhao Chai Xuesong Xie Bingan Lu Shuquan Liang Jiang Zhou 

机构地区：[1]School of Materials Science and Engineering,Key Laboratory of Electronic Packaging and Advanced Functional Materials of Hunan Province,Central South University,Changsha 410083,China [2]College of Biological and Chemical Engineering,Guangxi University of Science and Technology,Liuzhou 545006,China [3]School of Physics and Electronics,Hunan University,Changsha 410083,China

出　　处：《Science Bulletin》2022年第9期955-962,M0004,共9页科学通报（英文版）

基　　金：supported by the National Natural Science Foundation of China(51972346,51932011);the Hunan Natural Science Fund for Distinguished Young Scholar(2021JJ10064);the Program of Youth Talent Support for Hunan Province(2020RC3011);the Innovation-Driven Project of Centra South University(2020CX024)。

摘　　要：Aqueous zinc-ion batteries(ZIBs)are perceived as one of the most upcoming grid-scale storage systems.However,the issues of electrode dissolution,dendrite formation,and corrosion in traditional liquid electrolytes have plagued its progress.In this work,Zn dendrite growth and side reactions are effectively suppressed by a highly-confined tannic acid(TA)modified sodium alginate(SA)composite gel electrolyte(TA-SA).The ion-confinement effect is enhanced by divalent zinc ions coordinated with carboxyl groups and chelated with phenolic hydroxyl groups,thus guiding and regulating Zn deposition to achieve steady zinc plating/stripping behavior.As a consequence,the Zn/TA-SA/NH_(4)V_(4)O_(10) full cells deliver a high specific capacity of 238.6 mAh g^(-1) and maintain 94.51%over 900 cycles at 2 A g^(-1).Notably,after resting over 5 d,the capacity can be stabilized with a capacity retention of 97.25%after 200 cycles at 2 A g^(-1).This highlyconfined and hydrogen bond-strengthened gel electrolyte may provide an effective strategy for the future development of quasi-solid-state metal batteries.本文采用离子交联的方法,制备了高离子限域和氢键增强的单宁酸改性海藻酸基复合凝胶电解质.其中,单宁酸中的酚羟基和海藻酸钠中的羧基可以分别与锌离子进行配位和螯合,有效降低Zn^(2+)溶剂化壳层周围结合水分子的活性,通过增强的离子限域效应抑制了副反应和枝晶的生成,实现了锌的均匀沉积.利用该凝胶电解质组装的Zn/NH_(4)V_(4)O_(10)全电池搁置5d后,在2 A g^(-1)下循环200圈的容量保持率高达97.25%.同时,由于单宁酸中的羰基和海藻酸钠、水分子中的羟基之间形成强分子间氢键相互作用,电池在0℃低温下的循环稳定性也得到明显提升.此外,单宁酸中的酚羟基也可与钒基离子螯合,抑制循环过程中钒的溶解,为抑制钒基正极溶解和提高钒基电池小电流密度下的循环稳定性提供了新的解决方案.

关 键 词：Natural polymers Hydrogel electrolytes Cycling stability SELF-DISCHARGE Aqueous zinc-ion batteries 

分 类 号：TQ427.26[化学工程] TM912[电气工程—电力电子与电力传动]