Direct mask-free fabrication of patterned hierarchical graphene electrode for on-chip micro-supercapacitors

摘要

Graphene-based electrodes with rational structural design have shown extraordinary prospect for en-hanced electrical double-layer capacitance of micro-supercapacitors(MSCs).Herein,a facile fabrication method for flexible planar MSCs based on hierarchical graphene was demonstrated by using a laser-treated membrane for electrode patterning,complemented with hierarchical electrode configuration tak-ing full advantages of size-determined functional graphene.The in-plane interdigital shape of MSCs was defined through vacuum filtration with the assistance of the functionalized polypropylene(PP)mem-brane.The hierarchical graphene films were built by macroscopic assembly based on size effect of differ-ent lateral sized graphene sheets(rGO-LSL).The sample of MSCs based on rGO-L SL(MSCs-LSL)exhibited excellent volumetric capacitance of 6.7 F cm^(−3) and high energy density of 0.37 mWh cm−3.The MSCs-LSL presented superb flexibility and cycling stability with no capacitance deteroriated after 2000 cycles.This newly developed fabrication strategy is of good scalability and designability to manufacture flexible elec-trode for MSCs with customized shapes,while the construction of hierarchical graphene can enlighten the structural design of analogous two-dimensional materials for potential advanced electronics.