Surficial Structure Retention Mechanism for LiNi0.8Co0.15Al0.05O2 in a Full Gradient Cathode
Surficial Structure Retention Mechanism for LiNi0.8Co0.15Al0.05O2 in a Full Gradient Cathode
复制标题
全梯度阴极中LiNi0.8Co0.15Al0.05O2的表面结构保持机制
DOI：
10.1021/acsami.9b10160
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发表时间：
2019
影响因子：
9.5
通讯作者：
Shao Guosheng
中科院分区：
文献类型：
--
作者：
Liu Chaodeng;Cao Guoqin;Wu Zhihao;Hu Junhua;Wang Haoyang;Shao Guosheng
采用聚偏氟乙烯(PVDF)/Li6.75La3Z1.75Ta0.25O12（LLZTO）复合聚合物电解质和锂阳极耦合NCA阴极，组装了LiNi0.8Co0.15Al0.05O2（NCA）固体电池。类似nio的相变被认为是界面阻抗的原因，它导致循环过程中急剧的容量衰落。在阴极/电解质界面处制备了过量添加li6.75 la3 zr1.75 ta0.25 o12的梯度阴极，以克服增加的阻抗。利用高分辨率透射电镜和电子能量损失谱，证实了NCA表面形成了一个独特的局域阳离子迁移（LCM）区。LCM区域的形成阻碍了尖晶石晶格的进一步变形，并增强了其容量保留。
A LiNi0.8Co0.15Al0.05O2(NCA) solid battery was assembled by coupling an NCA cathode with a polyvinylidene fluoride (PVDF)/Li6.75La3Z1.75Ta0.25O12(LLZTO) composite polymer electrolyte and a Li anode. A NiO-like phase transition is regarded as the reason for interface impedance, which leads to drastic capacity fading during cycling. A gradient cathode with excessive addition of Li6.75La3Zr1.75Ta0.25O12was fabricated at the cathode/electrolyte interface to overcome the increased impedance. Using high-resolution transmission electron microscopy and electron energy loss spectra, the formation of a unique localized cation migration (LCM) region was confirmed on the NCA surface. The formation of an LCM region hindered further distortion and enhanced the capacity retention of the spinel lattice.