Electrochemically induced amorphous-to-rock-salt phase transformation in niobium oxide electrode for Li-ion batteries
Electrochemically induced amorphous-to-rock-salt phase transformation in niobium oxide electrode for Li-ion batteries
复制标题
锂离子电池用氧化铌电极的电化学诱导非晶岩盐相变
DOI：
10.1038/s41563-022-01242-0
复制
发表时间：
2022-05-02
期刊：
影响因子：
41.2
通讯作者：
Xiong, Hui
中科院分区：
文献类型：
--
作者：
Barnes, Pete;Zuo, Yunxing;Xiong, Hui
嵌入型金属氧化物由于在低电压下降低了Li电镀的风险，是用于安全可再充电锂离子电池的有前景的负极材料。然而，其较低的能量和功率密度沿着循环不稳定性仍然是其实施的瓶颈，特别是对于快速充电应用。在这里，我们报告了一个纳米结构的岩盐Nb 2 O 5电极形成通过无定形到结晶的转变，在重复的电化学循环与Li+。该电极可以可逆地循环三个锂/Nb 2 O 5，对应于在20 mA g（-1）下的269 mAh g（-1）的容量，并且在1 A g（-1）的高速率下保持191 mAh g（-1）的容量。它具有极好的循环稳定性，在200 mA g（-1）下400次循环的容量为225 mAh g（-1），库仑效率为99.93%。我们将增强的性能归因于立方岩盐框架，它促进了低能迁移路径。我们的工作表明，通过电化学循环诱导非晶纳米材料晶化是制备非常规高性能金属氧化物电极材料的一条很有前途的途径。插层型金属氧化物是锂离子电池有前途的阳极材料，但存在能量和功率密度低以及循环不稳定的问题。一个纳米结构的岩盐Nb 2 O 5形成通过非晶到结晶的转变，在循环过程中与Li+显示出增强的性能。
Intercalation-type metal oxides are promising negative electrode materials for safe rechargeable lithium-ion batteries due to the reduced risk of Li plating at low voltages. Nevertheless, their lower energy and power density along with cycling instability remain bottlenecks for their implementation, especially for fast-charging applications. Here, we report a nanostructured rock-salt Nb2O5 electrode formed through an amorphous-to-crystalline transformation during repeated electrochemical cycling with Li+. This electrode can reversibly cycle three lithiums per Nb2O5, corresponding to a capacity of 269 mAh g(-1) at 20 mA g(-1), and retains a capacity of 191 mAh g(-1) at a high rate of 1 A g(-1). It exhibits superb cycling stability with a capacity of 225 mAh g(-1) at 200 mA g(-1) for 400 cycles, and a Coulombic efficiency of 99.93%. We attribute the enhanced performance to the cubic rock-salt framework, which promotes low-energy migration paths. Our work suggests that inducing crystallization of amorphous nanomaterials through electrochemical cycling is a promising avenue for creating unconventional high-performance metal oxide electrode materials.Intercalation-type metal oxides are promising anodes for Li-ion batteries but suffer from low energy and power density together with cycling instability. A nanostructured rock-salt Nb2O5 formed via amorphous-to-crystalline transformation during cycling with Li+ is shown to exhibit enhanced performance.