荷兰代尔夫特理工大学Zhao, Chenglong团队在研究中取得进展。他们实现了锂氧化物阴极的化学短程失序。该研究成果发表在2024年5月8日出版的国际学术期刊《自然》上。

有序层状结构是锂离子阴极的重要组成部分。然而，在充电时，固有的脆弱的缺锂框架容易受到晶格应变和结构和/或化学机械降解的影响，导致容量迅速下降，电池寿命短。在该研究中，该课题组研究人员报告了一种解决这些问题的方法，将化学短程无序(CSRD)整合到氧化物阴极中，这涉及到晶格中元素在空间维度上的局部分布，跨越几个最邻近的间隔。这是在结构化学基本原理的指导下，通过改进的陶瓷合成工艺实现的。

为了证明其可行性，小组展示了CSRD的引入如何实质性地影响层状锂钴氧化物阴极的晶体结构。这表现在过渡金属环境及其与氧的相互作用中，有效地防止了晶体板在除锂过程中的有害滑动和结构恶化，同时影响电子结构，提高电子导电性。这些特性对锂离子存储能力非常有利，显著提高了循环寿命和倍率能力。

此外，小组发现CSRD可以通过改进的化学共掺杂引入到其他层状氧化物材料中，进一步说明了其提高结构和电化学稳定性的潜力。这些发现为氧化物阴极的设计开辟了新的途径，为CSRD对先进功能材料的晶体和电子结构的影响提供了见解。

附：英文原文

Title: Chemical short-range disorder in lithium oxide cathodes

Author: Wang, Qidi, Yao, Zhenpeng, Wang, Jianlin, Guo, Hao, Li, Chao, Zhou, Dong, Bai, Xuedong, Li, Hong, Li, Baohua, Wagemaker, Marnix, Zhao, Chenglong

Issue&Volume: 2024-05-08

Abstract: Ordered layered structures serve as essential components in lithium (Li)-ion cathodes1,2,3. However, on charging, the inherently delicate Li-deficient frameworks become vulnerable to lattice strain and structural and/or chemo-mechanical degradation, resulting in rapid capacity deterioration and thus short battery life2,4. Here we report an approach that addresses these issues using the integration of chemical short-range disorder (CSRD) into oxide cathodes, which involves the localized distribution of elements in a crystalline lattice over spatial dimensions, spanning a few nearest-neighbour spacings. This is guided by fundamental principles of structural chemistry and achieved through an improved ceramic synthesis process. To demonstrate its viability, we showcase how the introduction of CSRD substantially affects the crystal structure of layered Li cobalt oxide cathodes. This is manifested in the transition metal environment and its interactions with oxygen, effectively preventing detrimental sliding of crystal slabs and structural deterioration during Li removal. Meanwhile, it affects the electronic structure, leading to improved electronic conductivity. These attributes are highly beneficial for Li-ion storage capabilities, markedly improving cycle life and rate capability. Moreover, we find that CSRD can be introduced in additional layered oxide materials through improved chemical co-doping, further illustrating its potential to enhance structural and electrochemical stability. These findings open up new avenues for the design of oxide cathodes, offering insights into the effects of CSRD on the crystal and electronic structure of advanced functional materials.

DOI: 10.1038/s41586-024-07362-8

Source: https://www.nature.com/articles/s41586-024-07362-8