Lithium Perchlorate Additive for Dendritic-Free and Long-Life Li Metal Batteries

Nowadays, lithium (Li) metal is regarded as the most prospective electrode for the next generation of rechargeable batteries. Regrettably, poor coulombic efficiency (CE) and dendritic lithium development after repeated lithium electroplating/exfoliation treatments significantly restrict Li metal battery applications. To prevent dendrite growth of the Li metal during the reaction, an adequate amount of lithium perchlorate (LiClO4) is added to the ether-based electrolyte as an additive. When this additive is combined with lithium metal, a homogeneous and dense solid electrolyte interphase (SEI) layer rich in lithium chloride and lithium oxide can be created in situ. As a result of the general synergistic protection of LiCl and Li2O, the produced SEI has high ionic conductivity, allowing Li+ mobility, resulting in a more homogeneous distribution of electric field strength, helping to uniform Li deposition, and preventing the development of Li dendrites. As a result, the superior electrochemical performances are demonstrated by an ultralong cycling lifetime (>1500 h) in Li||Li symmetrical cells, coupled with a relatively low hysteresis voltage of 60 mV at 1 mA cm–2, a sufficiently high-quality CE (approximately 96% for 200 cycles at the current density of 0.5 mA cm–2 in Li||Cu cells), and an improved cycling stability in the Li||LiFePO4 complete cell.