Research Areas and Interests
Solid-State Lithium Ion Batteries (SSBs)
Next generation all solid-state batteries provide vastly improved performance due to their higher safety, longer cycling life and enhanced energy density. Typically, Interface issues and low ionic conductivity of solid-state electrolytes are the two most critical issues which have hindered its commercialization. Our research aims to understand the fundamental charge transfer mechanisms and kinetics within electrolyte and at electrolyte/electrode interface, and their impact to electrochemical performance of batteries. This will further guide rational design of innovative materials and architectures to engineer both the interface and microstructure of Li host, building high performance energy storage devices. We work on all solid-state Li-ion and “Li-beyond” batteries, including Li/Na-ion batteries, Li metal batteries, high volumetric microbatteries, flexible thin film batteries, and anode-free batteries.
Microbatteries
All-solid-state lithium microbatteries are gaining attention as promising next-generation energy storage technologies for portable and smart devices due to their higher safety, longer cycling life andenhanced energy density over traditional lithium-ion batteries that are based on liquid electrolyte systems. However, they have been limited to low capacity applications at micro amp-hours (µAh) levels and have had challenges in scaling up production. In this work, we demonstrate environmentally friendly scalable manufacturing of stacked thin-film lithium metal microbatteries with high capacity in the 1-100 mAh range. The optimized rechargeable solid-state lithium microbattery with anode-free design addresses electrolyte/electrode interface and cycling stability issues to reach high volumetric capacity, fast charge and high safety properties: (1) Rational design of the electrolyte/electrode interface to decrease the interfacial resistance of the core batteries. (2) Engineering of the anode-current collector to induce uniform lithium (Li) nucleation and homogeneous Li deposition, effectively suppressing Li dendrite formation. (3) Packaged stacked layer architecture that enables a parallel connection of all anodes and cathodes into a single anode and cathode connector that is surface mount compatible.
Photoelectrochemical (PEC) Carbon Dioxide Reduction
Fossil fuels currently provide for most of the world’s energy needs. However, consumption of fossil fuels releases pollutants and greenhouse gases that cause global climate change. Therefore, new sustainable energy sources are needed to meet the world’s increasing energy demand. Research on ways to remove CO2 from the atmosphere and convert it to other carbon compounds is also raising interests. We focuses on creating innovative, robust catalyst materials and electrolyte systems for electrochemical CO2capture and separation, and further utilizing photoelectrochemical (PEC) reactions to reduce CO2 into other carbon compounds.