Han Qiang, Yu Haifeng, Cai Lele, Chen Ling, Li Chunzhong, Jiang Hao
Shanghai Engineering Research Center of Hierarchical Nanomaterials, Key Laboratory for Ultrafine Materials of Ministry of Education, School of Materials Science and Engineering, East China University of Science and Technology, Shanghai 200237, China.
State Key Laboratory of Chemical Engineering, School of Chemical Engineering, East China University of Science and Technology, Shanghai 200237, China.
Proc Natl Acad Sci U S A. 2024 Mar 5;121(10):e2317282121. doi: 10.1073/pnas.2317282121. Epub 2024 Feb 28.
Micro-sized single-crystalline Ni-rich cathodes are emerging as prominent candidates owing to their larger compact density and higher safety compared with poly-crystalline counterparts, yet the uneven stress distribution and lattice oxygen loss result in the intragranular crack generation and planar gliding. Herein, taking LiNiCoMnO as an example, an optimal particle size of 3.7 µm is predicted by simulating the stress distributions at various states of charge and their relationship with fracture free-energy, and then, the fitted curves of particle size with calcination temperature and time are further built, which guides the successful synthesis of target-sized particles (-NCM83) with highly ordered layered structure by a unique high-temperature short-duration pulse lithiation strategy. The -NCM83 significantly reduces strain energy, Li/O loss, and cationic mixing, thereby inhibiting crack formation, planar gliding, and surface degradation. Accordingly, the m-NCM83 exhibits superior cycling stability with highly structural integrity and dual-doped m-NCM83 further shows excellent 88.1% capacity retention.
与多晶正极相比,微米级单晶富镍正极因其更高的压实密度和更高的安全性而成为突出的候选材料,然而,应力分布不均和晶格氧损失会导致晶内裂纹的产生和平面滑移。在此,以LiNiCoMnO为例,通过模拟不同充电状态下的应力分布及其与断裂自由能的关系,预测了3.7 µm的最佳粒径,然后进一步建立了粒径与煅烧温度和时间的拟合曲线,通过独特的高温短脉冲锂化策略指导成功合成具有高度有序层状结构的目标尺寸颗粒(-NCM83)。-NCM83显著降低了应变能、锂/氧损失和阳离子混合,从而抑制了裂纹形成、平面滑移和表面降解。因此,m-NCM83表现出优异的循环稳定性和高度的结构完整性,双掺杂的m-NCM83进一步显示出88.1%的优异容量保持率。