Battery Degradation Analysis and Electrolyte Development for High-Voltage Lithium Ion Battery Composed of Self-Standing Electrodes(3/3)

The project aims to analyze degradation products via mass spectrometry techniques, elucidate corresponding degradation mechanisms, and further design an optimum electrolyte for a high-voltage cell composed of self-standing electrodes. Since the self-standing electrode contains no binders and conductive carbons, the electrolyte degradation behavior is directly dominated by electrochemical reaction between active material and electrolyte. Simplifying electrode materials in this specific cell can contribute to investigating cell degradation and developing an optimum electrolyte for a high-voltage battery. The research works are divided into 3 parts (3 years). In the first part, we focus on fabrication of self-standing LiNi0.5Mn1.5O4 (LNMO) electrodes to stablish a high-voltage cell for investigating cell degradation behaviors under various operation conditions. We will discover important factors that dominate cell degradation based on electrode material analysis and cell electrochemical evaluation results. The second part is to utilize mass spectrometry techniques to identify degradation products in electrolyte and on electrode surface. Within the information of reactants and degradation products, we will elucidate reaction mechanisms accounting for the cell degradation, corresponding to deteriorated electrochemical performance. In addition, we will compare the cells composed of self-standing electrodes and conventional electrodes in terms of their degradation products as well as electrochemical performance. In the final part, we will optimize electrolyte for the high-voltage cell and examine its electrochemical performance. Specifically, we try to control degradation reactions by introducing electrolyte additives and modifying electrode surface to improve energy density, power density, cycling stability and safety for the high-voltage cell composed of self-standing electrodes.