Electrolytes and additives for batteries Part I: fundamentals and insights on cathode degradation mechanisms

Electrolytes and additives play a key role in improving the performance of high-energy-density batteries. Chemical complexity and structural hierarchy render rich information from both the bulk materials and the interfaces between electrolytes and electrodes. In this review, Part I serves as a self-contained article that addresses the fundamentals of batteries and cathode degradation mechanisms. Part II will introduce the fundamentals of electrolytes and additives and examine, in depth, developments regarding their intrinsic properties such as electrochemical stability and thermal stability, and the overall impact on batteries. Analytical and diagnostic tools for electrolytes and interfaces will also be discussed in Part II. • Introduction of batteries. • Electrolytes and additives are closely tied up with battery performances. • Categorized degradation mechanisms based on different structures.