In Situ Study of Lithium Electroplating in Anode-Free Solid-State Batteries by RBS Method

The Rutherford Backscattering Spectroscopy (RBS) method was employed for the in situ characterization of lithium galvanic deposition in an anode-free solid-state thin-film battery with a Ti|LiPON|LiCoO2|Ti structure. The RBS spectra were obtained from the battery in a charged and discharged state. Following the initial charge, the phosphorus and cobalt edges in the RBS spectra exhibited significant sloping. These changes were caused by irreversible and nonuniform deposition of lithium at the LiPON|Ti interface. Following the second charge-discharge cycle, reversible lithium deposition and stripping were observed within the areas established during the initial charge. RBS shows potential as a diagnostic tool for minimizing nonuniform lithium deposition in anode-free solid-state batteries.