Fig. 6: Electrochemical properties of QSSEs.

a–b Electrochemical floating test of different polymers based QSSEs using NCM85 positive electrode at 25 ± 1 °C. c Charge-discharge profiles of the Li||Li cells with P(DOA) and P(AEEO)-based QSSEs at the current of 0.5 mA cm⁻², the areal capacity of 0.5 mAh cm⁻² in each Li plating/stripping and 25 ± 1 °C. d The 3D mapping of CH₂O⁻, CH₃O⁻, F⁻, and LiF⁻ in the ToF-SIMS sputtering volumes of the Li-foil surface after 20 times Li plating/stripping in the Li||Li cells using EC-DEC-FEC liquid electrolyte, P(DOA) and P(AEEO)-based QSSEs containing EC-DEC-FEC at the current of 0.5 mA cm⁻², the areal capacity of 0.5 mAh cm⁻², and 25 ± 1 °C. e Schematic of potential interfacial degradation pathways of LEs and QSSEs, and the DRT (Distribution of relaxation times) transition result of impedance curves recorded during different time (from 0 to 360 hours) Li plating/stripping in Li||Li cells at 0.5 mA cm⁻², 0.5 mAh cm⁻², and 25 ± 1 °C, R₀ as contact resistance (the τ is in the range of 10⁻⁶ to 10⁻⁴), R_SEI as the resistance of Li⁺ transport through the SEI (the τ is in the range of 10⁻² to 10⁻⁴) and R_ct as charge transfer resistance (the τ is in the range of 10¹ to 10⁻²).