Lim Jin-Myoung, Oh Rye-Gyeong, Kim Duho, Cho Woosuk, Cho Kyeongjae, Cho Maenghyo, Park Min-Sik
Department of Mechanical and Aerospace Engineering, Seoul National University, Gwanak-ro 1, Gwanak-gu, Seoul, 08826, Republic of Korea.
Advanced Batteries Research Center, Korea Electronics Technology Institute, 68 Yatap-dong, Bundang-gu, Seongnam, 463-816, Republic of Korea.
ChemSusChem. 2016 Oct 20;9(20):2967-2973. doi: 10.1002/cssc.201600821. Epub 2016 Sep 21.
In lithium-ion batteries (LIBs) comprising spinel cathode materials, the dissolution of transition metals (TMs) in the cathodes causes severe cyclic degradation. We investigate the origin and mechanism of surface TM dissolution in high-voltage spinel oxide (LiNi Mn O ) nanoparticles to find a practical method for its mitigation. Atomic structures of the LiNi Mn O surfaces are developed, and the electronic structures are investigated by first-principles calculations. The results indicate that titanium is a promising dopant for forming a more stable surface structure by reinforcing metal-oxygen bonds in LiNi Mn O . Experimentally synthesized LiNi Mn O with titanium surface doping exhibits improved electrochemical performance by suppressing undesirable TM dissolution during cycles. The theoretical prediction and experimental validation presented here suggest a viable method to suppress TM dissolution in LiNi Mn O .
在包含尖晶石阴极材料的锂离子电池（LIBs）中，阴极中过渡金属（TMs）的溶解会导致严重的循环退化。我们研究了高压尖晶石氧化物（LiNiMn₂O₄）纳米颗粒表面TM溶解的起源和机制，以找到减轻其影响的实用方法。构建了LiNiMn₂O₄表面的原子结构，并通过第一性原理计算研究了电子结构。结果表明，钛是一种很有前景的掺杂剂，可通过加强LiNiMn₂O₄中的金属-氧键来形成更稳定的表面结构。通过实验合成的表面掺杂钛的LiNiMn₂O₄在循环过程中通过抑制不良的TM溶解而表现出改善的电化学性能。这里给出的理论预测和实验验证表明了一种抑制LiNiMn₂O₄中TM溶解的可行方法。
