Electrolyte-assisted low-voltage decomposition of Li2C2O4 for efficient cathode pre-lithiation in lithium-ion batteries Lithium oxalate (Li2C2O4) is an appealing cathode pre-lithiation additive for lithium-ion batteries (LIBs) but is hindered by high decomposition potential (>4.7 V). Under the liquid-solid synergistic effect of NaNO2 additive and LiNi0.83Co0.07Mn0.1O2 (NCM) cathode material, the decomposition efficiency of the miro-Li2C2O4 reaches 100% at the low charge cutoff voltage 4.3 V.