Advanced Li-ion Battery Engineering Laboratory and Key Laboratory of Graphene Technologies and Applications of Zhejiang Province, Ningbo Institute of Materials Technology & Engineering (NIMTE), Chinese Academy of Sciences , Ningbo, Zhejiang 315201, P.R. China.
ACS Appl Mater Interfaces. 2017 Feb 1;9(4):3661-3666. doi: 10.1021/acsami.6b14169. Epub 2017 Jan 23.
As rechargeable Li-ion batteries have expanded their applications into on-board energy storage for electric vehicles, the energy and power must be increased to meet the new demands. Li-rich layered oxides are one of the most promising candidate materials; however, it is very difficult to make them compatible with high volumetric energy density and power density. Here, we develop an innovative approach to synthesize three-dimensional (3D) nanoporous Li-rich layered oxides Li[LiNiCoMn]O, directly occurring at deep chemical delithiation with carbon dioxide. It is found that the as-prepared material presents a micrometer-sized spherical structure that is typically composed of interconnected nanosized subunits with narrow distributed pores at 3.6 nm. As a result, this unique 3D micro-/nanostructure not only has a high tap density over 2.20 g cm but also exhibits excellent rate capability (197.6 mA h g at 1250 mA g) as an electrode. The excellent electrochemical performance is ascribed to the unique nanoporous micro-nanostructures, which facilitates the Li diffusion and enhances the structural stability of the Li-rich layered cathode materials. Our work offers a comprehensive designing strategy to construct 3D nanoporous Li-rich layered oxides for both high volumetric energy density and power density in Li-ion batteries.
随着可充电锂离子电池在电动汽车车载储能领域的应用不断扩大，其能量和功率必须提高以满足新的需求。富锂层状氧化物是最有前途的候选材料之一；然而，要使它们与高体积能量密度和功率密度兼容非常困难。在这里，我们开发了一种创新的方法来合成三维（3D）纳米多孔富锂层状氧化物 Li[LiNiCoMn]O，直接与二氧化碳发生深度化学脱锂。结果发现，所制备的材料呈现出微米级的球形结构，通常由相互连接的纳米级亚单位组成，在 3.6nm 处具有狭窄分布的孔。因此，这种独特的 3D 微/纳米结构不仅具有超过 2.20gcm 的高振实密度，而且作为电极还表现出优异的倍率性能（在 1250mA g 下为 197.6mA h g）。优异的电化学性能归因于独特的纳米多孔微纳米结构，这有利于 Li 的扩散并增强富锂层状正极材料的结构稳定性。我们的工作为构建用于锂离子电池的高体积能量密度和功率密度的 3D 纳米多孔富锂层状氧化物提供了一种全面的设计策略。
