Thin lithium metal anodes for high energy rechargeable batteries via synergistic effects between surface treatments and electrolyte solution additives

A promising approach to increasing the energy density of rechargeable lithium batteries is to reduce their volume and weight while maintaining capacitance and operating voltage. A key requirement for significant volume reduction is decreasing anode thickness through ultrathin lithium metal films. Developing batteries with minimal active material at the anode is attractive; however, further advances are still required to overcome existing challenges. Current research focuses on optimizing thin lithium deposition layers by modifying current collector surfaces and incorporating electrolyte additives. These strategies aim to create lithiophilic collectors and stable protective layers that suppress dendritic lithium growth and minimize parasitic reactions. Here, these approaches are integrated by oxidizing copper foil substrates to increase surface roughness and applying electrochemical treatment to enhance lithium adhesion. LiNO 3 is used as an electrolyte additive to promote formation of passivating films on lithium surfaces, reducing side reactions. This combined strategy improves coulombic efficiency, capacity, and long-term cycling stability of thin lithium anodes at high current densities across electrolyte systems. The work described herein, namely lean lithium anodes using lithiophilic Cu current collectors and reactive electrolyte additives that enhance Li passivation via SEI-type surface layers, aims to promote development of practical high-energy-density rechargeable Li batteries.