State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics , Chinese Academy of Sciences , 1295 Ding Xi Road , Shanghai 200050 , China.
School of Materials Science and Engineering , Xiangtan University , Xiangtan 411105 , China.
ACS Appl Mater Interfaces. 2019 Jan 30;11(4):3869-3879. doi: 10.1021/acsami.8b17924. Epub 2019 Jan 14.
Suppressing the extrusion of Li dendrites and alleviating the volume expansion of Li anode during long-term cycling are of great significance to achieve highly reversible Li metal batteries of high energy density potential. However, the exploration of facile and effective solutions to smoothen anode surface is still a big challenge. Here, we propose a solid additive strategy by blending tailored metal-organic framework (MOF) grains with typical carbonate electrolyte to enable an ultrastable plating/stripping cycling of Li anode for at least 1400 h with evident inhibition of anode roughening and voltage polarization. Zr-based MOF (UiO-66) additive enables the smallest nucleation and plateau overpotentials (∼80 mV) during Li plating especially under high current density (2 mA/cm) and large areal capacity (4 mAh/cm). The kinetic and cyclic advantages of Li anode modulated by UiO-66 not only benefit from its intrinsic features (high surface area/porosity and thermal/electrochemical stability) but also from the reinforced solid electrolyte interface with low resistance, which consists of concentrated LiF and robust Zr-O-C moieties. Li-LiTiO cell based on MOF additive can achieve a high reversibility for at least 900 cycles.
抑制锂枝晶的挤出和缓解锂阳极在长期循环中的体积膨胀对于实现高能量密度潜力的高可逆性锂金属电池具有重要意义。然而,探索简便有效的方法来平滑阳极表面仍然是一个巨大的挑战。在这里,我们提出了一种通过将定制的金属有机骨架(MOF)颗粒与典型的碳酸盐电解质混合来实现固体添加剂策略,使锂阳极能够进行超稳定的电镀/剥离循环,至少 1400 小时,明显抑制阳极粗糙化和电压极化。Zr 基 MOF(UiO-66)添加剂在 Li 电镀过程中表现出最小的成核和平台过电势(约 80 mV),尤其是在高电流密度(2 mA/cm)和大面积容量(4 mAh/cm)下。UiO-66 调制的 Li 阳极的动力学和循环优势不仅得益于其固有特性(高表面积/孔隙率和热/电化学稳定性),还得益于具有低电阻的增强型固体电解质界面,其由浓缩的 LiF 和坚固的 Zr-O-C 基团组成。基于 MOF 添加剂的 Li-LiTiO 电池至少可以实现 900 次循环的高可逆性。