层状氧化物正极材料晶体结构与储钠性能探究

Exploration of Crystal Structure and Sodium Storage Performance of Transition Oxide Cathode Materials

钠离子电池因成本低和出色的低温性能,近年来被广泛关注且推到了应用市场端。层状氧化物正极材料由于具有较高的能量密度和较成熟的制备工艺而占据钠离子电池正极材料的主导地位。然而,层状氧化物残碱高,稳定性差,在长循环过程中易引发电解液氧化分解而导致电芯产气,限制了软包钠离子电池的应用。本文对比了多种单晶层状氧化物和多晶层状氧化物的特性和电化学性能,结果表明单晶结构的层状氧化物具有更加出色的循环稳定性,可以有效抑制电芯产气,为正极材料开发提供了指导。

Sodium ion batteries have been widely concerned and promoted to the application market due to their low cost and excellent low-temperature performance.At present,layered oxide positive electrodes occupy a dominant position due to their high energy density and mature preparation processes.However,layered oxides have high residual alkali and lack stability,which can easily cause electrolyte oxidation and decomposition during long cycles,leading to cell gas production,limiting the application and development of soft packaged sodium ion batteries.This work compares the characteristics and electrochemical performance of single crystal layered oxides and polycrystalline layered oxides,and the results show that single crystal structured layered oxides have better cycling stability and can effectively suppress cell gas production,providing guidance for cathode material development.