Designing and Demystifying the Lithium Metal Interface toward Highly Reversible Batteries
Rui Xu, Jun‐Fan Ding, Xia‐Xia Ma, Chong Yan, Yuxing Yao, Jia‐Qi Huang
Abstract
Abstract Reversible lithium (Li) plating/stripping is essential for building practical high‐energy‐density batteries based on Li metal chemistry, which unfortunately remains a severe challenge. In this contribution, it is demonstrated that through the rational regulation of strong Li + −anion coordination structures in a highly compatible low‐polarity solvent, 2‐methyl tetrahydrofuran, the Li plating/stripping assisted by a nucleation modulation procedure delivers a remarkably high average Coulombic efficiency under rather demanding conditions (99.7% and 99.5% under 1.0 mA cm −2 , 3.0 mAh cm −2 and 3.0 mA cm −2 , 3.0 mAh cm −2 , respectively). The exceedingly reversible cycling obtained herein is fundamentally correlated with the flattened Li deposition and minimized solid electrolyte interphase (SEI) generation/reconstruction in the customized condition, which notably restrains the growth rates of both dead Li 0 (0.0120 mAh per cycle) and SEI‐Li + (0.0191 mAh per cycle) during consecutive cycles. Benefiting from the efficient Li plating/stripping manner, the assembled anode‐free Cu|LiFePO 4 (2.7 mAh cm −2 ) coin and pouch cells exhibit impressive capacity retention of 43.8% and 41.6% after 150 cycles, respectively, albeit with no optimization on the test conditions. This work provides guidelines into the targeted interfacial design of high‐efficiency working Li anodes, aiming to pave the way for the practical deployment of high‐energy‐density Li metal batteries.