A Novel Laser Patterned Flexible Graphene Nanoplatelet Electrode for Fast Charging Lithium-Ion Battery Applications

A flexible anode was developed with graphene nanoplatelet (xGnP) as the anode material for fabricating fast charging lithium-ion battery. The ink consists of xGnP as active material along with C-45 carbon black as conductive additive and polyvinylidene fluoride (PVDF) as binder. The ink was bar coated on to a flexible copper film to form anode. Then the anode was laser patterned to introduce secondary pore network (SPN) consisting of pores with diameter of ~75 µm with an edge-to-edge distance of ~70 µm between the pores. Half-cell lithiumion batteries was assembled with laser patterned anode and lithium metal foil as counter electrode. Ethylene carbonate and dimethyl carbonate (EC: EDC) in 50/50 (v/v) mixed with 1M lithium hexafluorophosphate (LiPF6) was used as electrolyte in assembled coin-cells. Rate performance was tested for laser patterned electrodes at different current rates. Resultant laser-patterned xGnP electrode delivered enhanced specific capacity of 333 mAh/g when compared to bar-coated electrode without SPN (243 mAh/g) at 6A/g current rate.