Lithium Metal Polymer Battery: Towards Optimized Cathodes and Crosslinked Polymer Electrolytes

Abstract

Although lithium metal polymer batteries (LMPBs) have lots of advantages such as high energy density, design flexibility and enhanced safety, they have not been widely used in the commercial market due to low ionic conductivity and poor interfacial stability towards electrodes comparing to liquid electrolytes. However, most of researches on LMPBs have been focused for electrolytes themselves without broad cell performance data such as cycle life and rate capability. Furthermore, as discovered in previous works on commercial LIBs, the electrode density and thickness are also very crucial parameters governing the electrochemical performance of batteries. For the purpose of providing basic but essential electrochemical properties of LMPB, we have manufactured four different LiFePO4 cathodes with different densities and thicknesses. Their physical and electrochemical properties are investigated by using the unit cells consisting of LiFePO4/cross-linked polymer electrolyte/Li metal. In particular, with the optimized cathode and crosslinked polymer electrolyte, high capacity retention could be realized at even 5C and room temperature. Acknowledgements This research was financially supported by the Ministry of Education, Science and Technology (MEST) and National Research foundation (NRF) of Korea through the Human Resource Training Project for Regional Innovation (2014066977) and Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education (2014046008). Figure 1