Reversible planar gliding and microcracking in a single-crystalline Ni-rich cathode
Reversible planar gliding and microcracking in a single-crystalline Ni-rich cathode
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DOI：
10.1126/science.abc3167
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发表时间：
2020-12-11
期刊：
影响因子：
56.9
通讯作者：
Xiao, Jie
中科院分区：
文献类型：
--
作者：
Bi, Yujing;Tao, Jinhui;Xiao, Jie
高能量富镍正极将在先进锂离子电池中发挥关键作用，但其存在对湿度敏感、副反应以及产气等问题。单晶富镍正极通过减少相界和材料表面，在应对其多晶对应物所面临的挑战方面具有巨大潜力。然而，高性能单晶富镍正极的合成极具挑战性，尽管在单晶富镍正极中过电位、微观结构和电化学行为之间存在基本联系。我们在单晶富镍正极中观察到沿(003)面的可逆平面滑移和微裂纹。微观结构缺陷的可逆形成与晶格中U原子浓度梯度引起的局部应力相关，这为通过合成改进减轻颗粒破裂提供了线索。
High-energy nickel (Ni)-rich cathode will play a key role in advanced lithium (Li)-ion batteries, but it suffers from moisture sensitivity, side reactions, and gas generation. Single-crystalline Ni-rich cathode has a great potential to address the challenges present in its polycrystalline counterpart by reducing phase boundaries and materials surfaces. However, synthesis of high-performance single-crystalline Ni-rich cathode is very challenging, notwithstanding a fundamental linkage between overpotential, microstructure, and electrochemical behaviors in single-crystalline Ni-rich cathodes. We observe reversible planar gliding and microcracking along the (003) plane in a single-crystalline Ni-rich cathode. The reversible formation of microstructure defects is correlated with the localized stresses induced by a concentration gradient of U atoms in the lattice, providing clues to mitigate particle fracture from synthesis modifications.