Graphene Flake-Based Electrodes for High-Energy and Power Lithium-Ion Semi-flexible Rechargeable Batteries

摘要

Developing devices and related materials for storing and producing electricity is a key issue to meet the global energy demand. Low-cost and high-performance energy-storage devices are important for sustainable energy utilization. Recently, lithium-ion battery (LIB) is emerging as a promising power source for high-performance electronics. However, their technological drawbacks have hindered the development of LIB with improved specific capacity, stable cyclic and coulombic efficiency for portable electronics application, due to the lack of availability of reliable electrode materials that provided superior electrochemical properties. As a solution to this problem, we herein demonstrated two types of few-layered graphene produced by Fenton reaction (FG) and Hummers method (HG) used for the fabrication of electrodes on flexi copper and aluminum foils in two different ways. Lithium iron phosphate (LiFePO_4 or LFP) mixed with super-P carbon black (SP) and fabricated cathode, FG and HG, respectively, blended with SP and fabricated two anodes, by carefully balancing the cell composition of the anode and cathode. An optimal cell performance in terms of specific capacity and stable cyclability depends on the fabrication method of electrodes and their chemical composition. The FG electrodes showed a specific capacity of 186 mAh g~(-1) at 150 mA g~(-1) charge/discharge (C/D) current rate while HG showed a specific capacity of 195mAh g~(-1) at same C/D rate without capacity decay during 30 cycles and an excellent cycling stability was also observed when HG was used in cathode with SP in the same ratio at 150, 300 and 450 mA g~(-1) C/D rate in full LIB.