Interfacial Regulation of Ni-Rich Cathode Materials with an Ion-Conductive and Pillaring Layer by Infusing Gradient Boron for Improved Cycle Stability
Interfacial Regulation of Ni-Rich Cathode Materials with an Ion-Conductive and Pillaring Layer by Infusing Gradient Boron for Improved Cycle Stability
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通过注入梯度硼来调节具有离子导电层和柱撑层的富镍正极材料的界面以提高循环稳定性
DOI：
10.1021/acsami.9b18542
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发表时间：
2020
影响因子：
9.5
通讯作者：
Guo Xiao-Dong
中科院分区：
文献类型：
--
作者：
Yang Wen;Xiang Wei;Chen Yan-Xiao;Wu Zhen-Guo;Hua Wei-Bo;Qiu Lang;He Feng-Rong;Zhang Jun;Zhong Ben-He;Guo Xiao-Dong
富镍正极材料LiNixCoyAl 1-x-yO 2（0.8 <x< 1）具有能量密度高、环境友好、成本低等优点，被认为是下一代锂电池最有前途的候选材料。不幸的是，在极端条件下由不稳定的表面性质和固有的结构不稳定性引起的容量衰减限制了大规模的商业利用。本文中，通过在煅烧过程中梯度引入硼和锂反应性包覆，构造了具有层（R3·m）芯、NiO盐状（Fm 3·m）相和非晶态离子导电LiBO 2（LBO）层的界面调节富Ni正极材料LiNi 0. 87 Co 0. 10 Al 0. 03 O 2。LiNbO 3 LBO层不仅耗尽了残余的锂物质，而且还充当了Li+传输和隔离有害反应的层。亚表层的NiO盐状相由于柱效应可以增强层芯的结构稳定性。在功能性杂化表面层和硼掺杂的积极作用下，改性阴极表现出增强的Li+电导率、结构稳定性、H2-H3相变的可逆性、抑制的副反应、改善的过渡金属溶解和优异的电化学性能。在0.2C、3.0- 4.3V的电位范围内，硼改性的阴极放电容量为211.99mAh g-1，循环寿命为89.43%。
Ni-rich cathodes LiNixCoyAl1–x–yO2(0.8 <x< 1) with high energy density, environmental benignity, and low cost are regarded as the most promising candidate materials for next-generation lithium batteries. Unfortunately, capacity fading derived from unstable surface properties and intrinsic structural instability under extreme conditions limits large-scale commercial utilization. Herein, an interface-regulated Ni-rich cathode material LiNi0.87Co0.10Al0.03O2with a layer (R3̅m) core, a NiO salt-like (Fm3̅m) phase, and an ultrathin amorphous ion-conductive LiBO2(LBO) layer is constructed by gradient boron incorporation and lithium-reactive coating during calcination. The ultrathin LBO layer not only exhausts residual lithium species but also acts as a layer for Li+transport and insulation of detrimental reaction. The NiO salt-like phase in the subsurface could enhance the structural stability of the layer core for the pillar effects. With the positive role provided by the functional hybrid surface layer and boron doping, the modified cathode exhibits enhanced Li+conductivity, structural stability, reversibility of the H2–H3 phase transition, suppressed side reactions, ameliorated transition-metal dissolution, and excellent electrochemical performance. Especially, a 1% wt boron-modified cathode delivers a discharge capacity of 211.99 mA h g–1in the potential range of 3.0–4.3 V at 0.2 C and excellent cycle life with a capacity retention of 89.43% after 200 cycles at 1 C.