Authors: Yunfei Yang, Kun Wang, Xuehui Gao, Muxi Jiang, Chengkai Wu, Min Ling, Zhongwei Chen
Published: 2024-11-09
Source: Full article
AbstractLithium (Li) metal batteries (LMBs) have garnered widespread attention due to their high specific capacity. However, the growth of lithium dendrite severely limits their practical applications. Herein, a novel strategy is proposed to regulate the overall potential strength and lithium ions (Li+) concentration on the surface of the current collector by utilizing densely distributed tip effects. This concept is exemplified through the construction of lithiophilic Cu1.8Se/CuO heterojunction needle array on the Cu foil, ultimately achieving dendrite‐free lithium deposition. Based on the simulation in COMSOL multiphysics and experimental research, this design is demonstrated to enrich Li+ on the current collector surface, delay the formation of space charge regions, and mitigate the growth of lithium dendrites. Additionally, a built‐in electric field (BIEF) triggered by the heterointerface between Cu1.8Se and CuO further alleviates the Li+ concentration gradient on the electrode surface, achieving uniform bottom‐up deposition of Li within the array structure. Consequently, the symmetrical cell exhibits an ultra‐long cycle life of 2400 h (1 mA cm−2, 1 mAh cm−2) with an extremely low overpotential of 13 mV. Furthermore, full batteries using LiFePO4 as the cathode exhibit superior cycle stability and rate performance. This study presents a promising approach for designing dendrite‐free current collectors in LMBs.