Layered Oxide Cathode‐Electrolyte Interface towards Na‐Ion Batteries: Advances and Perspectives

Abstract

With the ever increasing demand for low‐cost and economic sustainable energy storage, Na‐ion batteries have received much attention for the application on large‐scale energy storage for electric grids because of the worldwide distribution and natural abundance of sodium element, low solvation energy of Na+ ion in the electrolyte and the low cost of Al as current collectors. Starting from a brief comparison with Li‐ion batteries, this review summarizes the current understanding of layered oxide cathode/electrolyte interphase in NIBs, and discusses the related degradation mechanisms, such as surface reconstruction and transition metal dissolution. Recent advances in constructing stable cathode electrolyte interface (CEI) on layered oxide cathode are systematically summarized, including surface modification of layered oxide cathode materials and formulation of electrolyte. Urgent challenges are detailed in order to provide insight into the imminent developments of NIBs.

Improvement of cycle life for layered oxide cathodes in sodium-ion batteries

“…2d). 89,90 Specifically, the failure mechanism of the layered oxide cathodes can be summarized as follows. (i) Fluorinated salts or organic solvents (such as NaPF 6 and fluoroethylene carbonate (FEC) additives) react with trace amounts of water in the electrolyte to generate HF, which corrode the electrodes, causing metal dissolution on the cathode surface and severe capacity degradation during cycling.…”

Regulating Interfacial Compositions to Build a Stable Superlattice Structure of Layered Oxide Cathode Materials for Sodium-Ion Batteries

“…The special superlattice structure ensures the structural stability of SIBs so that the material undergoes a solid solution reaction under high pressure. However, the surface of the cathode particles is attached to impurities such as Na 2 CO 3 and NaHCO 3 because of their poor air stability. − This leads to a series of side reactions during charging and discharging, reducing the Coulombic efficiency and cycle life of the battery. In addition to the ensuing Li migration and Mn dissolution, the honeycomb superlattice structure was destroyed, and the electrochemical performance deteriorated. , …”

Electrode/electrolyte additives for practical sodium-ion batteries: a mini review

“…[14][15][16][17][18][19][20] Even though the cost of lithium is increasing rapidly due to its uneven distribution and the lack of resources, the demand for LIBs for consumer electronics, communication, computers and electrified vehicles is still growing rapidly. [21][22][23][24][25][26] The high-quality lithium resources in the world are mostly distributed in Australia and South America, where there may be political issues. In addition, the price of lithium resources has been increasing in recent years, reaching almost dozens of times that of sodium resources.…”

“…14–20 Even though the cost of lithium is increasing rapidly due to its uneven distribution and the lack of resources, the demand for LIBs for consumer electronics, communication, computers and electrified vehicles is still growing rapidly. 21–26…”