Surface Coupling between Mechanical and Electric Fields Empowering Ni-Rich Cathodes with Superior Cyclabilities for Lithium-Ion Batteries,Advanced Science

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Surface Coupling between Mechanical and Electric Fields Empowering Ni-Rich Cathodes with Superior Cyclabilities for Lithium-Ion Batteries
Advanced Science ( IF 14.3 ) Pub Date : 2022-04-27 , DOI: 10.1002/advs.202200622
Zhongsheng Dai ₁ , Jianhang Wang ₁ , Huiling Zhao _{1,

2} , Ying Bai _{1,

2}

Affiliation

Ni-rich cathodes with high energy densities are considered as promising candidates for advanced lithium-ion batteries, whereas their commercial application is in dilemma due to dramatic capacity decay and poor structure stability stemmed from interfacial instability, structural degradation, and stress–strain accumulation, as well as intergranular cracks. Herein, a piezoelectric LiTaO₃ (LTO) layer is facilely deposited onto Li[Ni_xCo_yMn₁₋_x₋_y]O₂ (x = 0.6, 0.8) cathodes to induce surface polarized electric fields via the intrinsic stress–strain of Ni-rich active materials, thus modulating interfacial Li⁺ kinetics upon cycling. Various characterizations indicate that the electrochemical performances of LTO-modified cathodes are obviously enhanced even under large current density and elevated temperature. Intensive explorations from in situ X-ray diffraction technique, finite element analysis, and first-principle calculation manifest that the improvement mechanism of LTO decoration can be attributed to the enhanced structural stability of bulk material, suppressed stress accumulation, and regulated ion transportation. These findings provide deep insight into surface coupling strategy between mechanical and electric fields to regulate the interfacial Li⁺ kinetics behavior and enhance structure stability for Ni-rich cathodes, which will also arouse great interest from scientists and engineers in multifunctional surface engineering for electrochemical systems.

中文翻译：

机械场和电场之间的表面耦合使富镍正极具有优异的锂离子电池循环能力

具有高能量密度的富镍正极被认为是先进锂离子电池的有希望的候选者，但由于界面不稳定、结构退化和应力应变累积导致容量急剧衰减和结构稳定性差，其商业应用陷入困境。以及晶间裂纹。在此，压电LiTaO ₃ (LTO)层很容易沉积在Li[Ni _x Co _y Mn ₁₋ _x ₋ _y ]O ₂ ( x = 0.6, 0.8)阴极上，通过固有应力应变感应表面极化电场。富含镍的活性材料，从而调节循环时的界面Li ⁺动力学。各种表征表明，即使在大电流密度和高温下，LTO修饰的正极的电化学性能也明显增强。原位X射线衍射技术、有限元分析和第一性原理计算的深入探索表明，LTO修饰的改进机制可归因于增强块体材料的结构稳定性、抑制应力积累和调节离子传输。这些发现为机械场和电场之间的表面耦合策略提供了深入的见解，以调节界面Li ⁺动力学行为并增强富镍正极的结构稳定性，这也将引起科学家和工程师对电化学系统多功能表面工程的极大兴趣。

更新日期：2022-04-27

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