A successive “conversion-deposition” mechanism achieved by micro-crystalline Cu2O modified current collector for composite lithium anode

• Published in: Journal of industrial and engineering chemistry (Seoul, Korea) 2023, 120(0), , pp.285-292
• Main Authors: Cai, Yifei, Qin, Bin, Li, Chun, Si, Xiaoqing, Cao, Jian, Zheng, Xiaohang, Qiao, Liang, Qi, Junlei
• Format: Article
• Language: English
• Subjects: Composite Li anode; Conversion-deposition mechanism; Coulombic efficiency; Current collector; Li metal anode; 화학공학
• ISSN: 1226-086X; 1876-794X
• DOI: 10.1016/j.jiec.2022.12.035

•Defective and defect-free micro-crystalline Cu2O modified Cu current collectors were prepared via low pressure thermal oxidation method.•The defect-free micro-crystalline Cu2O can generates lithiophilic LiCuO through conversion reaction, which provides conversion-type capacity and affinity to metal Li.•Ultra-high average coulombic efficiency (99.3 % at 1 mA cm−2 for 800 cycles) is achieved in the composite Li anode based on a successive “conversion-deposition’’ mechanism. Lithium (Li) metal is a promising material for high-energy–density batteries, but it is still plagued by obvious capacity degradation and low average Coulombic efficiency resulting from dendrite Li propagation. One main reason is the electro-mechanic coupled failure of plated Li on the current collector, which contributes to non-dense Li deposition on the anode. Transition metal oxides (TMOs) with a conversion-type mechanism have been used directly as the anode materials for lithium ion batteries, which demonstrated better electro-mechanical stability than metal Li. Herein, a successive''conversion-deposition'' mechanism is ingeniously developed to restrain the generation of dendritic Li. Specifically, a micro-crystalline Cu2O modified current collector was prepared, in which Li+ are sequentially inserted into Cu2O and deposited in the form of Li metal at successive low potential. A Li-Cu half-cell based on the hybrid mechanism sustains a high Coulombic efficiency of over 99.3 % in up to 800 cycles. This work ingeniously inhibits the generation of dendrite Li by incorporating conversion-type materials with deposition-dissolution type metal Li, which contributes to a novel concept for the design of functional current collectors for composite Li anodes.