Zhang Jinfang, Li Xiaofeng, Li Ying, Wang Huiqi, Ma Cheng, Wang Yanzhong, Hu Shengliang, Wei Weifeng
School of Materials Science and Engineering, North University of China, Taiyuan, China.
State Key Laboratory of Powder Metallurgy, Central South University, Changsha, China.
Front Chem. 2018 May 25;6:186. doi: 10.3389/fchem.2018.00186. eCollection 2018.
A new class of freestanding cross-linked hybrid polymer electrolytes (HPEs) with POSS as the cross-linker was prepared by a one-step free radical polymerization reaction. Octavinyl octasilsesquioxane (OV-POSS) with eight functional corner groups was used to provide cross-linking sites for the connection of polymer segments and the required mechanical strength to separate the cathode and anode. The unique cross-linked structure offers additional free volume for the motion of EO chains and provides fast and continuously interconnected ion-conducting channels along the nanoparticles/polymer matrix interface. The HPE exhibits the highest ionic conductivity of 1.39 × 10 S cm, as well as excellent interfacial compatibility with the Li electrode at 80°C. In particular, LiFePO/Li cells based on the HPE deliver good rate capability and long-term cycling performance with an initial discharge capacity of 152.1 mAh g and a capacity retention ratio of 88% after 150 cycles with a current density of 0.5 C at 80°C, demonstrating great potential application in high-performance LIBs at elevated temperatures.
通过一步自由基聚合反应制备了一类以倍半硅氧烷（POSS）为交联剂的新型独立式交联混合聚合物电解质（HPEs）。具有八个官能端基的八乙烯基倍半硅氧烷（OV-POSS）用于提供聚合物链段连接的交联位点以及分离阴极和阳极所需的机械强度。独特的交联结构为环氧乙烷（EO）链的运动提供了额外的自由体积，并沿着纳米颗粒/聚合物基体界面提供了快速且连续互连的离子传导通道。该HPE在80°C时表现出最高离子电导率1.39×10 S cm，以及与锂电极优异的界面相容性。特别是，基于该HPE的磷酸铁锂/锂（LiFePO/Li）电池具有良好的倍率性能和长期循环性能，在80°C、0.5 C电流密度下，初始放电容量为152.1 mAh g，150次循环后容量保持率为88%，显示出在高温下高性能锂离子电池（LIBs）中的巨大潜在应用价值。
