P2/P3 composite layered cathode materials for sodium ion batteries

Sodium-ion batteries (NIBs) are a more sustainable, cheaper and safer energy storage solution to lithium-ion batteries (LIBs). The best performing NIBs contain sodium layered oxide cathode materials, based around sodium, nickel and manganese, which typically adopt one of three structures P2,P3 (with trigonal prismatic sodium and O3 (with octahedral sodium). Recent studies have demonstrated that materials comprising nanoscale intergrowths of different phases can result in superior properties compared to single-phase equivalents. We have prepared a series of P2/P3 composites with excellent cycling performance and high voltages that are competitive with current commercial materials. This experiemnt seeks to understand the transition metal distribution in the component phases and the structural evolution on charge/discharge.

钠离子电池（Sodium-ion Batteries, NIBs）是相较于锂离子电池（Lithium-ion Batteries, LIBs）更具可持续性、成本更低且安全性更优的储能解决方案。性能最优的钠离子电池采用以钠、镍、锰为核心组分的钠基层状氧化物正极材料，此类材料通常具备三种晶体结构之一：P2、P3（钠离子配位环境为三棱柱）以及O3（钠离子配位环境为八面体）。近期研究表明，由不同晶相纳米共生结构构成的材料，相较单相同类材料，可展现出更优异的性能。本研究团队制备了一系列P2/P3复合正极材料，其具备优异的循环性能与高电压特性，可与当前商业化同类材料相媲美。本实验旨在探究各晶相中的过渡金属分布规律，以及材料在充放电过程中的结构演化机制。