Mitigating Voltage Decay of Li-Rich Cathode Material via Increasing Ni Content for Lithium-Ion Batteries
Mitigating Voltage Decay of Li-Rich Cathode Material via Increasing Ni Content for Lithium-Ion Batteries
复制标题
通过增加锂离子电池的镍含量来缓解富锂正极材料的电压衰减
DOI：
10.1021/acsami.6b06733
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发表时间：
2016-08-10
影响因子：
9.5
通讯作者：
Wan, Li-Jun
中科院分区：
文献类型：
--
作者：
Shi, Ji-Lei;Zhang, Jie-Nan;Wan, Li-Jun
富锂层状材料被认为是未来高能量密度锂离子电池最有前途的正极材料。然而，它们在循环时会遭受严重的电压衰减，这阻碍了它们的进一步商业化。在这里，我们报道了一种高镍含量的富锂层状材料0.5Li(2)MnO(3)中心点0.5LiNi(0.8)-Co0.1Mn0.1O2，与传统的富锂材料相比，其在长期循环过程中表现出更慢的电压衰减。 200 个循环后电压衰减为 201 mV。结合原位X射线衍射（XRD）、异位X射线衍射、异位X射线光电子能谱和扫描透射电子显微镜，我们证明镍离子作为稳定离子抑制活性Mn3+离子的Jahnn-Teller效应，改善d-p杂化并支撑层状结构作为支柱。此外，镍离子可以在过渡金属层和中间层之间迁移，从而避免形成尖晶石状结构，从而减轻电压衰减。我们的研究结果为开发具有减轻电压衰减和长寿命的富锂层状材料提供了一种简单有效的途径，从而促进其在高能量密度锂离子电池中的进一步应用。
Li-rich layered materials have been considered as the most promising cathode materials for future high-energy-density lithium-ion batteries. However, they suffer from severe voltage decay upon cycling, which hinders their further commercialization. Here, we report a Li-rich layered material 0.5Li(2)MnO(3)center dot 0.5LiNi(0.8)-Co0.1Mn0.1O2 with high nickel content, which exhibits much slower voltage decay during long-term cycling compared to conventional Li-rich materials. The voltage decay after 200 cycles is 201 mV. Combining in situ X-ray diffraction (XRD), ex situ XRD, ex situ Xray photoelectron spectroscopy, and scanning transmission electron microscopy, we demonstrate that nickel ions act as stabilizing ions to inhibit the Jahnn-Teller effect of active Mn3+ ions, improving d-p hybridization and supporting the layered structure as a pillar. In addition, nickel ions can migrate between the transition-metal layer and the interlayer, thus avoiding the formation of spinel-like structures and consequently mitigating the voltage decay. Our results provide a simple and effective avenue for developing Li-rich layered materials with mitigated voltage decay and a long lifespan, thereby promoting their further application in lithium-ion batteries with high energy density.