摘要
水系锌离子电池具有低成本、安全、环保等优点,在规模化储能和智能可穿戴方面极具应用前景.提高其循环稳定性以及循环寿命是实现水系锌离子电池进一步应用的关键问题之一.本工作采用二维层状蒙脱土(MMT)和丙烯酰胺单体,通过两步法合成了具有三维网状结构的蒙脱土-聚丙烯酰胺水凝胶电解质(Montmorillonite-polyacrylamide hydrogel,MMT-PAM).蒙脱土的加入为丙烯酰胺单体的原位聚合提供了吸附位点,并通过MMT和PAM高分子链之间的氢键作用显著提高了水凝胶的机械性能,抑制了锌枝晶生长(在0.5 mA·cm^(-1)电流密度下稳定循环250 h).此外,蒙脱土表面丰富的负电荷为Zn2+的快速传输提供更多离子传输通道,提高其离子电导率(室温下为34 mS·cm^(-1)),赋予MMT-PAM水凝胶电解质更好的倍率性能和循环稳定性.基于上述优点,组装的水系Zn-MnO_(2)电池在0.2 A·g^(-1)的电流密度下提供了289 mA·h·g^(-1)的比容量,且可稳定循环2000次.此外,使用MMT-PAM水凝胶作为电解质制备的柔性电池在经过不同外界条件冲击下依然可正常工作,表现出了其在柔性电子领域的应用可行性.
With the advantages of being cheap,safe,and environmentally friendly,aqueous Zn-ion batteries(AZIBs)show promise in large-scale energy storage and smart wearables.Moreover,with the expansion of the field of flexible electronics,the huge demand potential of wearable smart electronic devices is increasingly being underscored,which proposes higher requirements for the structural and electrochemical stability of energy storage devices and device safety in physical deformation processes.Aqueous electrolyte-based AZIBs are prone to interface separation during bending,which affects battery stability and makes it difficult to realize further practical applications in flexible electronics.Unlike aqueous electrolytes,hydrogel electrolytes are flexible and foldable,assuring the structural and performance stability of flexible energy storage devices under the action of external impacts.Particularly,polyacrylamide(PAM)-based hydrogels are the preferred materials for preparing hydrogel electrolytes due to their better ionic conductivity,strain,and stability.Herein,montmorillonite-PAM hydrogel(MMT-PAM)electrolytes with a three-dimensional network structure were produced by a twostep process using two-dimensional layered montmorillonite and acrylamide monomer.The addition of montmorillonite provides adsorption sites for the in situ polymerization of acrylamide monomer to enhance the mechanical properties of the hydrogel and facilitates the rapid transport of Zn2+through the abundant negative charge on the MMT surface,increasing its ionic conductivity(34 mS∙cm^(-1)at room temperature is much higher than that of the PAM hydrogel electrolyte(17 mS∙cm^(-1)))to obtain MMT-PAM hydrogel electrolytes with better electrochemical properties.The MMT-PAM hydrogel electrolyte-based Zn-MnO_(2)batteries-demonstrated a specific capacity of 289 mA·h∙g^(-1)at a current density of 0.2 A∙g^(-1)and could be stably cycled for 2000 cycles,whereas the PAM hydrogel electrolyte-based Zn-MnO_(2)batteries only cycled for hundreds of cycles at the same current density before shortcircuiting,thus demonstrating the long battery cycle life of the MMT-PAM hydrogel electrolyte-based Zn-MnO_(2)batteries.The MMT-PAM-based batteries maintained a high specific capacity even at a high current density of 4 A∙g^(-1).Furthermore,flexible batteries based on MMT-PAM hydrogel electrolytes could still work properly under different external impacts,such as cutting and piercing.The prepared flexible batteries were folded and immersed in aqueous solution to provide stable voltage and remarkable water resistance,demonstrating their possible application in flexible electronics.Therefore,this work sheds light on the possibility of further application of hydrogel electrolytes in aqueous Zn-MnO_(2)batteries and the further development of flexible energy storage devices based on hydrogel electrolytes.
作者
季善果
袁鲁宁
徐加虎
秦硕
胡媛媛
于鸿达
杨凯
JI Shanguo;YUAN Luning;XU Jiahu;QIN Shuo;HU Yuanyuan;YU Hongda;YANG Kai(College of Chemistry and Material Science,Shandong Agriculture University,Tai’an 271000,China;Key Laboratory of Agricultural Film Application of Ministry of Agriculture and Rural Affairs,Tai’an 271000,China;Department of Emergency Management of Shandong Province,Ji’nan 250000,China)
出处
《工程科学学报》
EI
CSCD
北大核心
2024年第1期89-96,共8页
Chinese Journal of Engineering
基金
国家自然科学基金资助项目(22001057,21902044)
山东省高等学校青创人才引育计划。
作者简介
通信作者:胡媛媛,E-mail:yyhu@sdau.edu.cn;通信作者:于鸿达,E-mail:hdyu@sdau.edu.cn。
