{"title":"Lattice plainification flattens the crystal structure of nickel-rich layered cathodes.","authors":"Pengcheng Li, Zhuo Peng, Zhihao Sun, Chengyu Li, Jianjun Ma, Jun Wang, Run Yu, Cairong Jiang, Xiang Gao, Wenge Yang, Dongliang Chao, Yongjin Chen","doi":"10.1039/d5mh00975h","DOIUrl":null,"url":null,"abstract":"<p><p>The extremely fast charging/discharging of nickel-rich LiNi<sub><i>x</i></sub>Co<sub><i>y</i></sub>Mn<sub>1-<i>x</i>-<i>y</i></sub>O<sub>2</sub> (NCM) cathodes has raised concerns about rapid capacity decay. The birth defects and fragile lattice result in the sluggish Li<sup>+</sup> diffusion kinetics and unfavorable structural degradation. Moreover, lattice strain, mechanical failures, surface reconstruction, and interfacial side reactions accelerate the decay process. Here, a proof-of-principle study of the lattice plainification (LP) strategy in a high-nickel NCM cathode is reported. The introduction of Al and Zr in transition metal layers by a wet chemistry and calcination method enables the simplification of the complex lattice structures to obtain an order phase and repair the various defects of NCM, thereby enhancing the lithium-ion transport. The modified LP-NCM exhibits a high initial discharge capacity of 157.3 mAh g<sup>-1</sup> with a capacity retention of 81% after 300 cycles at a 5C rate, significantly outperforming the pristine counterpart (50.9%). The LP-NCM/Gr pouch cells presented impressive cycling performance, achieving 80% capacity retention over 1000 cycles at 1C, which far surpasses the performance of the pristine NCM. Our method eliminates the rocksalt and disordered phases, and suppresses oxygen, lithium, and transition metal vacancies, as well as Li/Ni mixing. LP-NCM after cycling exhibits nanopores rather than cracks of pristine NCM. Our investigations reveal that the lattice plainification design approach flattens and toughens up the crystal lattice, which contributes to robust structural stability and improves the structure degradation, mechanical failures, and gas release. Our findings underscore the importance of lattice engineering and demonstrate the potential of the lattice plainification strategy for designing high-performance cathodes.</p>","PeriodicalId":87,"journal":{"name":"Materials Horizons","volume":" ","pages":""},"PeriodicalIF":12.2000,"publicationDate":"2025-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Materials Horizons","FirstCategoryId":"88","ListUrlMain":"https://doi.org/10.1039/d5mh00975h","RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"CHEMISTRY, MULTIDISCIPLINARY","Score":null,"Total":0}
引用次数: 0
Abstract
The extremely fast charging/discharging of nickel-rich LiNixCoyMn1-x-yO2 (NCM) cathodes has raised concerns about rapid capacity decay. The birth defects and fragile lattice result in the sluggish Li+ diffusion kinetics and unfavorable structural degradation. Moreover, lattice strain, mechanical failures, surface reconstruction, and interfacial side reactions accelerate the decay process. Here, a proof-of-principle study of the lattice plainification (LP) strategy in a high-nickel NCM cathode is reported. The introduction of Al and Zr in transition metal layers by a wet chemistry and calcination method enables the simplification of the complex lattice structures to obtain an order phase and repair the various defects of NCM, thereby enhancing the lithium-ion transport. The modified LP-NCM exhibits a high initial discharge capacity of 157.3 mAh g-1 with a capacity retention of 81% after 300 cycles at a 5C rate, significantly outperforming the pristine counterpart (50.9%). The LP-NCM/Gr pouch cells presented impressive cycling performance, achieving 80% capacity retention over 1000 cycles at 1C, which far surpasses the performance of the pristine NCM. Our method eliminates the rocksalt and disordered phases, and suppresses oxygen, lithium, and transition metal vacancies, as well as Li/Ni mixing. LP-NCM after cycling exhibits nanopores rather than cracks of pristine NCM. Our investigations reveal that the lattice plainification design approach flattens and toughens up the crystal lattice, which contributes to robust structural stability and improves the structure degradation, mechanical failures, and gas release. Our findings underscore the importance of lattice engineering and demonstrate the potential of the lattice plainification strategy for designing high-performance cathodes.
富镍LiNixCoyMn1-x-yO2 (NCM)阴极的极快充放电引起了人们对快速容量衰减的担忧。先天缺陷和脆弱的晶格导致Li+扩散动力学缓慢和不利的结构降解。此外,晶格应变、机械失效、表面重建和界面副反应加速了衰变过程。本文报道了高镍NCM阴极中晶格平化(LP)策略的原理证明研究。通过湿化学和煅烧方法在过渡金属层中引入Al和Zr,可以简化复杂的晶格结构,获得有序相,修复NCM的各种缺陷,从而增强锂离子的输运。改良后的LP-NCM具有157.3 mAh g-1的高初始放电容量,在5C倍率下,300次循环后容量保持率为81%,明显优于原始版本(50.9%)。LP-NCM/Gr袋状电池表现出令人印象深刻的循环性能,在1C下循环1000次后,其容量保持率达到80%,远远超过原始NCM的性能。我们的方法消除了岩盐和无序相,抑制了氧、锂和过渡金属空位以及Li/Ni混合。循环后的LP-NCM呈现纳米孔,而不是原始NCM的裂纹。我们的研究表明,晶格平化设计方法使晶格变得平坦和增韧,有助于增强结构稳定性,改善结构退化、机械故障和气体释放。我们的发现强调了晶格工程的重要性,并展示了晶格化策略在设计高性能阴极方面的潜力。