Nanoscale Surface Modification of Lithium-Rich Layered-Oxide Composite Cathodes for Suppressing Voltage Fade
Nanoscale Surface Modification of Lithium-Rich Layered-Oxide Composite Cathodes for Suppressing Voltage Fade
复制标题
用于抑制电压衰减的富锂层状氧化物复合阴极的纳米级表面改性。
DOI：
10.1002/anie.201506408
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发表时间：
2015-10-26
影响因子：
16.6
通讯作者：
Liu, Meilin
中科院分区：
文献类型：
--
作者：
Zheng, Fenghua;Yang, Chenghao;Liu, Meilin
富锂层状氧化物是锂离子电池的有前途的阴极材料，并且表现出超过250 mAh g−1的高可逆容量。然而，电压衰减是在它们能够找到实际应用之前需要克服的主要问题。在此，对Li1.2Mn0.54Ni0.13Co0.13O2（LLMO）氧化物进行纳米级LiFePO 4（LFP）表面改性。所得材料联合收割机结合了本体掺杂和表面涂覆的优点，因为LLMO晶体结构通过阳离子掺杂而稳定，并且LLMO阴极材料被保护免受有机电解质引起的腐蚀。用5重量% LFP改性的LLMO阴极（LLMO-LFP 5）显示出抑制的电压衰减和在0.1C下282.8 mAh g-1的放电容量，在120次循环后容量保持率为98.1%。此外，结合到LLMO表面中的纳米级LFP层可以有效地保持锂离子和电荷传输通道，并且LLMO-LFP 5阴极表现出优异的倍率容量。
Lithium‐rich layered oxides are promising cathode materials for lithium‐ion batteries and exhibit a high reversible capacity exceeding 250 mAh g−1. However, voltage fade is the major problem that needs to be overcome before they can find practical applications. Here, Li1.2Mn0.54Ni0.13Co0.13O2 (LLMO) oxides are subjected to nanoscale LiFePO4 (LFP) surface modification. The resulting materials combine the advantages of both bulk doping and surface coating as the LLMO crystal structure is stabilized through cationic doping, and the LLMO cathode materials are protected from corrosion induced by organic electrolytes. An LLMO cathode modified with 5 wt % LFP (LLMO–LFP5) demonstrated suppressed voltage fade and a discharge capacity of 282.8 mAh g−1 at 0.1 C with a capacity retention of 98.1 % after 120 cycles. Moreover, the nanoscale LFP layers incorporated into the LLMO surfaces can effectively maintain the lithium‐ion and charge transport channels, and the LLMO–LFP5 cathode demonstrated an excellent rate capacity.