摘要：锂金属负极(LMA)具有前所未有的理论比容量和超低的氧化还原电位,因此锂金属电池(LMBs)得到了广泛的研究.然而,不可控的锂枝晶生长和易碎的固体电解质界面相(SEI)严重阻碍了LMBs的实际商业应用.本文制备了二维sp^(2)碳连接的共价有机框架sp^(2)c-COF,并在LMA表面构建了人工SEI膜,以抑制锂枝晶的形成,并调节界面稳定性.sp^(2)c-COF被设计成沿x和y方向全π共轭的高导电性的结构,从而起到降低界面阻抗、促进Li^(+)通量均匀分布的作用.因此,sp^(2)c-COF改性的对称电池Li^(+)迁移数高达0.85,并且在5mA cm^(-2)电流密度下具有较长的循环寿命(4000 h)和极低的过电位(10 mV).此外还利用原位光学显微镜研究了锂沉积行为,结果表明sp^(2)c-COF能显著提高LMA的界面稳定性.该策略对抑制锂枝晶的形成具有重要的应用价值,可促进COF人工SEI膜的发展.

摘要：To address the issues of reduced graphene oxide(RGO) dispersion in copper(Cu) matrix and interface bonding between RGO and Cu, an electrostatic adsorption method with interface transition phase design was employed to prepare the RGO/Cu based composites. Cu-Ti alloy powder was employed to improve the combination by forming carbides at the RGO-Cu interface. It was noted that the mechanical property of 0.3 wt.%RGO/Cu-Ti composite was increased by 60% compared with that of the matrix. Strengthening mechanism analysis suggested that the enhancement of the mechanical property was ascribed to the load transfer and second phase strengthening which were from the improved dispersion of RGO and the in-situ formed titanium carbide phase.