Copper foil after hydrothermal treatment in acidified tungstate solution as conductor- and binder-Free anode electrodes for high performance lithium-ion batteries

Copper foil is commonly used as anode current collector in the battery industry due to its high conductivity, good elasticity and relative abundance. Herein, copper foil was hydrothermally treated in acidified tungstate solution, resulting in the formation of Cu2O and WO3 agglomerated clusters on the copper foil substrate with sufficient open space between neighboring clusters. The copper foil after hydrothermal treatment was directly used as the conductor- and binder-free anode electrode for lithium-ion batteries. Cyclic voltammetry and charge-discharge measurements were performed to investigate the reversible areal capacity, cycling stability and rate capability of the as-prepared electrode. A reversible areal capacity of 357 μAh cm−2 was obtained after 50 cycles at a current density of 60 μA cm−2. Even cycled at a current density of 600 μA cm−2, a reversible capacity of 8 μAh cm−2 remained. When the current density returns to 60 μA cm−2, the conductor- and binder-free electrode exhibits an areal discharge capacity of 430 μAh cm−2.