Joule ( IF 39.8 ) Pub Date : 2022-06-17 , DOI: 10.1016/j.joule.2022.05.018 Xinye Zhao , Yaosen Tian , Zhengyan Lun , Zijian Cai , Tina Chen , Bin Ouyang , Gerbrand Ceder
The cycling of cathode materials for Li-ion batteries is often accompanied by a change in volume, posing a challenge to the integrity of cathode particles and electrolyte/cathode interface in solid-state batteries. To enhance capacity retention, it is thus crucial to design materials that remain structurally invariant during electrochemical cycling. Here, we use well-calibrated first-principles calculations to systematically investigate the effect of transition-metal chemistry, cation ordering, Li site occupancy, redox-inactive species, anion substitution, and cation migration on the volume change associated with the delithiation of cathode materials with an FCC anion framework. Suggested by an in-depth first-principles Monte Carlo simulation of the Li+–V3+–Nb5+–O2−–F− system, we experimentally confirm Li1.3V0.4Nb0.3O2 and Li1.25V0.55Nb0.2O1.9F0.1 as nearly zero-strain cathodes. Our study establishes a fundamental understanding of the important physical descriptors that determine the dimensional change of materials during cycling and provides general guidelines for designing low- or zero-strain cathodes.
中文翻译:
零应变锂离子正极的设计原则
锂离子电池正极材料的循环往往伴随着体积的变化,这对固态电池中正极颗粒和电解质/正极界面的完整性提出了挑战。因此,为了提高容量保持率,设计在电化学循环过程中保持结构不变的材料至关重要。在这里,我们使用经过良好校准的第一性原理计算来系统地研究过渡金属化学、阳离子排序、Li 位点占据、氧化还原惰性物质、阴离子取代和阳离子迁移对与正极脱锂相关的体积变化的影响。具有 FCC 阴离子骨架的材料。由 Li + –V 3+ –Nb 5+的深入第一性原理 Monte Carlo 模拟建议-O 2- -F -体系,我们通过实验证实 Li 1.3 V 0.4 Nb 0.3 O 2和 Li 1.25 V 0.55 Nb 0.2 O 1.9 F 0.1几乎是零应变正极。我们的研究建立了对决定材料在循环过程中尺寸变化的重要物理描述符的基本理解,并为设计低应变或零应变阴极提供了一般指导。