Conformal Coating of Elastomeric Conducting Polymer with Ionic Conductivity on Ni-rich Layered Cathodes for Enhanced Redox Cycle Stability of Lithium-ion Batteries

Description

Sustainable energy utilization needs the effective energy storage system. The electrification of transportation also demands batteries with high energy density, long service life and good safety. For one material to fulfill the three requests is almost impossible. However, composite materials may hold the answers for such questions. For example, nickel-rich layered metal oxide cathode materials show the potential of high energy density. Its service life is relatively short and it is not yet safe. Coating a thin layer of polymer was shown to enhance the performance of such cathode materials. Conformal coating of conductive polymers was confirmed in the researchers' lab toimprove the performance of service life, safety and also power delivery.In this project, the investigators propose to coat a thin conformal layer of elastomeric conductive polymer with good ionic conductivity. This could be done using chemical vapor deposition method which is a green in nature and easy in operation. The conductive polymers will be PEDOT, PANi. The polymer with good ionic conductivity would be PEG. The elasticity will be provided by PB, the synthetic rubber. PVI may be able to provide elasticity and ion conductivity judged from its similar structure to that of PEG.The coated cathode materials will be tested for their physical, chemical and electrochemical properties. Their morphology, surface composition, electron/ion conductivity, elasticity on the performance of battery cells will be investigated in-depth. State-of-the-art instruments such as, In-situ HEXRD, HRTEM, SEM, XPS, FTIR, TGA/DSC, ICP-MS, DMA, would be employed to reveal the information behind the expected significant improvement of the performance of the cathodes by conformal coating of elastomeric conducting polymers with ionic conductivity.The success of the project will make a significant impact on the battery communities in Hong Kong, China and the world.