近日，中南大学袁明亮团队报道了原位硼化物表面复合物使钠离子层状氧化物阴极具有优异的电化学性能和空气稳定性。该研究于2025年10月21日发表在《颗粒学报》杂志上。

O3型层状氧化物是钠离子电池最有前景的阴极候选材料之一，但其实际应用受到高压下不可逆氧氧化还原、寄生副反应和明显的水分敏感性的限制。

研究组提出一步H₃BO₃处理，引入原位硼化物配合物，使近表面B掺杂和形成保形硼酸钠界面相。这两种修饰协同作用：B的掺入强化了层状框架并抑制了4.0 V以上的氧氧化还原，而硼酸钠层具有高Na⁺导电性，具有机械界面屏障的功能。这些效应共同抑制过渡金属溶解，减缓电解质分解，促进Na⁺快速运输。得益于这种设计，优化后的阴极在0.1C时提供160.5 mAh g^-1，在1C下循环200次后保持85.3%的容量。

此外，硼酸钠涂层有效地阻止H⁺/H₂O的进入，赋予了卓越的空气稳定性。经过150次循环后，3天老化的原始阴极保留了4.7%的新容量，而优化后的阴极保持了近乎原始的循环稳定性。即使在暴露7天后，也只检测到微量的Na₂CO₃杂质。这项工作建立了原位硼化物复合物作为实现电化学性能和耐湿钠离子阴极的可行策略，用于电网规模的储能。

附：英文原文

Title: In situ boride surface complex enables Na-ion layered oxide cathodes with superior electrochemical performance and air stability

Author: Mingliang Yuan

Issue&Volume: 2025/10/21

Abstract: O3-type layered oxides are among the most promising cathode candidates for sodium-ion batteries, yet their practical use is constrained by irreversible oxygen redox at high voltages, parasitic side reactions, and pronounced moisture sensitivity. Here, we propose a one-step H3BO3 treatment that introduces an in-situ boride complex, enabling near-surface B doping and the formation of a conformal sodium borate interphase. The dual modification operates synergistically: B incorporation reinforces the layered framework and suppresses oxygen redox above 4.0 V, while the sodium borate layer, endowed with high Na+ conductivity, functions as a robust interfacial barrier. These effects collectively suppress transition-metal dissolution, mitigate electrolyte decomposition, and promote rapid Na+ transport. Benefiting from this design, the optimized cathode delivers 160.5 mAh g-1 at 0.1C and retains 85.3% capacity after 200 cycles at 1C. Moreover, the sodium borate coating effectively blocks H+/H2O ingress, conferring exceptional air stability. After 150 cycles, 3-days-aged pristine cathode retains 4.7% of the fresh capacity, whereas optimized cathode maintains nearly pristine cycling stability. Even after seven days of exposure, only trace Na2CO3 impurities are detected. This work establishes in situ boride complexes as a viable strategy to achieve electrochemically robust and moisture-tolerant sodium-ion cathodes for grid-scale energy storage.

DOI: 10.1016/j.partic.2025.09.020

Source: https://www.sciencedirect.com/science/article/abs/pii/S1674200125002731