Lithium Insertion in Polymer‐Derived Silicon Oxycarbide Ceramics
Lithium Insertion in Polymer‐Derived Silicon Oxycarbide Ceramics
复制标题
DOI：
10.1111/j.1551-2916.2009.03539.x
复制
发表时间：
2010-04
影响因子：
3.9
通讯作者：
P. E. Sánchez-Jiménez;R. Raj
中科院分区：
文献类型：
--
作者：
P. E. Sánchez-Jiménez;R. Raj
聚合物衍生的碳氧化硅陶瓷的电解插入锂的数据进行了分析，这些陶瓷的纳米畴模型。该模型由三个分子构建块构建：石墨烯，二氧化硅四面体和混合键四面体。在混合键中，硅原子由氧和碳共享。被认为是由C，SiO2和SiC形成的三角形的组成制度接壤。大多数情况下，考虑含有“游离"碳的非化学计量组成。数据符合现象学描述，其中硅基混合键四面体螯合B50 000 mAh/g-原子的当量，而“游离碳”可以螯合B5000 mAh/g-原子，用于锂插入的可逆部分。然而，靠近SiC-C和SiC-SiO2连接线的组合物可测量地偏离这一总体情况。
Data for the electrolytic insertion of lithium into polymerderived silicon oxycarbide ceramics are analyzed in terms of a nanodomain model for these ceramics. The model is constructed from three molecular building blocks: graphene, silicon dioxide tetrahedra, and mixed bond tetrahedra. In mixed bonds, the silicon atom is shared by both oxygen and carbon. The composition regime being considered is bordered by a triangle formed by C, SiO2, and SiC. Mostly, the nonstoichiometric compositions containing ‘‘free’’ carbon are considered. The data fit a phenomenological description where silicon-based mixed bond tetrahedra sequester an equivalent of B50 000 mAh/g-atom, while ‘‘free carbon’’ can sequester B5000 mAh/g-atom, for the reversible portion of the lithium insertion. The compositions lying close to the SiC–C, and SiC–SiO2 tie lines, however, deviate measurably from this general picture.