Flexible Energy Storage: From Supercapacitor to Aqueous Electrolyte Battery
Chunyi Zhi

City University of Hong Kong

Abstract: Our research focuses on development of flexible energy storage/conversion devices, including supercapacitors, batteries and metal air batteries.       
Wearable electronic textiles that store capacitive energy are a next frontier in personalized electronics. We demonstrate a new electrolyte comprising polyacrylic acid dual cross-linked by hydrogen bonding and vinyl hybrid silica nanoparticles (VSNPs-PAA) that addresses all the superior functions and provide an ultimate solution to the intrinsic self-healability and high stretchability of a supercapacitor. Supercapacitors with VSNPs-PAA as the electrolyte are self-healed, achieving an excellent healing efficiency of ~100% even after 20 cycles of breaking/healing. By a designed facile electrode fabrication procedure, they are stretched up to 600% strain with performance enhanced. 
In addition, we have successfully fabricated an extremely safe, wearable and rechargeable solid-state aqueous electrolyte based battery with a new hierarchical polymer electrolyte (HPE). The HPE works as both an efficient ionic conductor and a highly effective separator, providing high flexibility, high ionic conductivity as well as the excellent safety performance for the battery. This solid state ZIB exhibits a high energy density (14.6 mWh cm−3 normalized to the volume of the whole device), a high specific capacity of 280 mAh g-1 and high capacity retention of 97% after 1000 cycles. Moreover, this battery exhibits high flexibility and greatly enhanced safety performance. 

Biography: Dr. Chunyi Zhi got his PhD degree in physics from institute of physics, Chinese Academy of sciences. After that, he started to work as a postdoctoral researcher in National Institute for Materials Science (NIMS) in Japan, followed by a research fellow in International Center for Young Scientists in NIMS and a permanent position in NIMS as a senior researcher. He is currently an associate professor in Department of Materials Science & Engineering, City University of Hong Kong. Zhi’s research is currently focused on flexible/wearable energy storage devices etc. He has published more than 190 papers with a citation of >9000 and h-index of 52 (ISI).