Highlights A class of hydrogel electrolytes that couple high adhesion and anti-freezing properties is developed. Zn/Li hybrid capacitors based on the hydrogel electrolyte can tolerate low temperatures and accommodate dynamic deformations across a temperature range of 25 to − 60 °C. This work highlights an advancement for promoting next-generation energy storage system with low-temperature capability and mechanical durability.

Flexible supercapacitors are becoming increasingly popular in portable and wearable electronics. However, conventional flexible supercapacitors typically exhibit laminated multilayer configurations, inevitably causing the irreversibly interfacial slippage or even delamination under deformations. In this study, an all-in-one supercapacitor with highly integrated structure is constructed through in-situ polymerization of conducting polyaniline on a hydrogel electrolyte. Because the extensive intermolecular interactions between polymer chains and nanoparticles can dissipate energy, the prepared hydrogel electrolyte shows outstanding mechanical prop-erties. At the same time, the introduction of ethylene glycol endows hydrogel electrolyte with a higher binding energy between ethylene glycol and water molecule to break hydrogen bonds between water molecules, thus enabling the hydrogel electrolyte to be anti-freezing. Benefiting from the novel all-in-one structure, the device maintains 100% and 97.5% of its initial capacitance after 6000 charging/discharging cycles at room temperature and-20 degrees C respectively. Besides, the highly integrated structure endows the device with excellent capacitance retentions of 99.2% and 97.5% after 5000 bending and stretching cycles respectively. More importantly, the device still works well under bending, twisting, and stretching states at-20 degrees C. This work provides an inspiring pathway to develop flexible all-in-one supercapacitors and broadens the practical application range of energy storage devices in various fields.

以大豆蛋白(SPI)、丙烯酰胺(AAm)和ZnCl2为原料,热引发聚合制备了一种具备抗冻特性的大豆蛋白基凝胶电解质材料,探究了温度对材料离子电导率和力学性能的影响,并分析了其作用机制.研究结果表明:该凝胶电解质具有优异的抗冻性能,其中ZnCl2的引入形成了大量Zn2+的溶剂化结构,破坏了水分子间的氢键,降低了凝胶电解质的凝固点;凝胶基体和盐离子的协同作用赋予了凝胶电解质高压缩回弹性和耐疲劳强度.对凝胶电解质的低温离子电导率分析表明:ZnCl2≥5 mol/kg,凝胶电解质在-30℃的低温下离子电导率仍有 3.65×10-3 S/cm.对凝胶电解质的低温力学性能分析发现:凝胶电解质在-30℃下经历应变为 80％的 100 次压缩循环后仍能保持结构完整,应力保持率>85％,塑性变形率为15％.同时,利用凝胶电解质组装的电化学电容器表现出良好的耐低温性能,电流密度5A/g下,器件在-30℃下仍能够正常工作,其电容保持率达83.2％,在-30℃下经历10000次循环充放电电容保持率达92％.

Flexible supercapacitors are promising energy storage devices for their portability and long cycle life. However, the weak interfacial adhesion between contiguous layers of flexible supercapacitors limits their practical applications. Here, a hydrogel matrix by integrating Ag-Lignin nanoparticles into polyacrylamide network is reported. Due to the unique interwoven-microfibrils structure and non-covalent interactions, the obtained hydrogel matrix shows strong adhesion and toughness. The assembled all-hydrogel supercapacitor based on the hydrogel matrix has robust interfaces and shows high specific capacitance (298.6 F g -1 at 10 mV s -1 ), outstanding rate performance, a high energy density of 13.7 Wh kg -1 at the power density of 201.4 W kg -1 and 91.9% capacitance retention after 5000 cycles. Remarkably, the all-polymer device shows superior capacitance retention after mechanical deformations of 5000 cycles without slippage between contiguous layers. This study proposes a commendably effective approach to improve the interfacial adhesion in integrated supercapacitors and extends the application range of flexible supercapacitors.

以甲基丙烯酸甲酯(MMA)和丙烯酸丁酯(BA)为主单体,烯丙氧基壬基酚聚氧乙烯(10)醚硫酸铵(DNS-86)为反应型乳化剂,1,6-己二醇二丙烯酸酯(HDDA)和1,4-丁二醇二丙烯酸酯(BDDA)为交联单体,通过种子乳液半连续法成功制备了丙烯酸酯乳液.研究了不同交联单体及用量对乳液性能以及乳胶膜的交联度、吸水率、耐热稳定性和力学性能的影响.研究结果表明:随着交联单体HDDA和BDDA质量分数的增加,乳液的固含率和表面张力无明显变化,乳液粒径增加,粒径分布变宽;当w(BDDA)=10.0％,乳液粒径由103 nm增长至140 nm,乳胶膜耐水性和耐热稳定性明显提高;当w(HDDA)=5.0％,最低吸水率仅有2.33％;当w(HDDA)=10.0％,初始分解温度高达422.9℃.

Flexible supercapacitors are promising energy storage devices benefitting from their portability and long cycle life. However, the weak interfacial adhesion between contiguous layers of flexible supercapacitors limits their practical applications. Here, a hydrogel matrix by integrating Ag-Lignin nanoparticles into polyacrylamide network is reported. Due to the unique interwoven-microfibrils structure and non-covalent interactions, the obtained hydrogel matrix presents largely enhanced adhesion and mechanical toughness. The assembled all-hydrogel supercapacitor based on the hydrogel matrix has robust interfaces and shows high specific capacitance (298.6 F g(-1) at 10 mV s(-1)), outstanding rate performance, delivering high energy density of 13.7 Wh kg(-1) and high capacitance retention of 89.9% after 10,000 cycles. Remarkably, the all-polymer device shows superior capacitance retention after mechanical deformations of 5000 cycles without slippage happens between contig-uous layers. This study proposes an effective approach to improving the interfacial adhesion in integrated supercapacitors and extending the application scope of flexible supercapacitors.

以甲基丙烯酸甲酯(MMA)、丙烯酸丁酯(BA)为主单体,通过种子乳液半连续法合成了纳米级丙烯酸酯乳液,并考察了三种乳化剂对丙烯酸酯乳液及胶膜性能的影响.研究结果表明:反应型乳化剂(SR-10/JS-20)制备的丙烯酸酯聚合物其耐水性和耐电解质稳定性均优于传统乳化剂(SDS);当w(SR-10)=3％(相对于单体质量而言)的体系所制备的乳胶膜交联度达到42.7％,乳胶膜的初始分解温度达到378.9℃,耐热稳定性得到了很大提高;通过原子力显微镜(AFM)测试发现,反应型乳化剂(SR-10/JS-20)制备的丙烯酸酯乳液在成膜干燥过程中未发生乳化剂的迁移、聚集现象.