Laser fabrication of all-solid-state microsupercapacitors with ultrahigh energy and power based on hierarchical pore carbon

Abstract

Microsupercapacitors (MSCs) are used as power sources or energy storage units in microelectronic devices. This study fabricates all-solid-state MSCs using a laser for the micromachining of substrates coated with activated mesophase pitch (aMP) to produce in-plane interdigitated microelectrodes for use in conjunction with gel-state electrolytes. Due to the inclusion of hierarchically-connected micropores and mesopores, aMP carbon has considerable capability for charge storage and the delivery of energy at high rates. Through reduction in the finger width, the proposed laser-patterned design substantially reduces the resistance to ion drift in the electrolyte bulk and ion diffusion across the carbon-film network. The use of an ionogel enables the MSC to reach stack capacitance of 12Fcm−3, stack energy of 16mWhcm−3, and stack power of 160Wcm−3. These energy and power values approach those obtained from thin-film lithium ion batteries and aluminum electrolytic capacitors, respectively; this synergy between high energy and power is unprecedented for MSCs. The proposed MSCs exhibit outstanding cycling stability and those using ionogel present high thermal stability. The proposed fabrication methods enable the on-chip integration of microelectronic devices and therefore provide an opportunity for the development of a variety of micro/nano-sized energy devices.