Scalable fabrication of high-power graphene micro-supercapacitors for flexible and on-chip energy storage

Abstract

The rapid development of miniaturized electronic devices has increased the demand for compact on-chip energy storage. Microscale supercapacitors have great potential to complement or replace batteries and electrolytic capacitors in a variety of applications. However, conventional micro-fabrication techniques have proven to be cumbersome in building cost-effective micro-devices, thus limiting their widespread application. Here we demonstrate a scalable fabrication of graphene micro-supercapacitors over large areas by direct laser writing on graphite oxide films using a standard LightScribe DVD burner. More than 100 micro-supercapacitors can be produced on a single disc in 30 min or less. The devices are built on flexible substrates for flexible electronics and on-chip uses that can be integrated with MEMS or CMOS in a single chip. Remarkably, miniaturizing the devices to the microscale results in enhanced charge-storage capacity and rate capability. These microsupercapacitors demonstrate a power density of B200 W cm À 3 , which is among the highest values achieved for any supercapacitor.

On‐Chip Micro‐Pseudocapacitors for Ultrahigh Energy and Power Delivery

“…The capacitance degradation in ionic liquids, as compared with in aqueous electrolytes, is a common issue, and mainly originates from the low ionic conductivity of the ionic liquid electrolytes (only a few milliSiemens per centimeter at room temperature, Table S2, Supporting Information) 14. However, the stack capacitance of the hierarchical NPG/MnO 2 MPCs is still one order of magnitude higher than that of the reported graphene‐based MSCs, 1.40–2.35 F cm −3 , with an ionogel electrolyte 9. In addition, because of the threefold increase in the operating voltage, the ionogel‐based MPCs possess a high energy density of 12.7 mW h cm −3 at 0.25 mA cm −2 , which is about three times higher than that of PVA‐LiCl based MPCs (4.4 mW h cm −3 at 0.25 mA cm −2 ).…”

“…In contrast to thin film batteries whose properties drop dramatically with the decrease of sizes, micro‐supercapacitors often have better performance in comparison with their bulk counterparts as the result of reduced transport length of charge and electrolytes 1, 2. Interdigital planar form micro‐supercapaciotors (MSCs) with active carbon,3 carbide‐derived carbon,4 carbon nanoparticles/nanotubes2, 5, 6, 7 and multilayer graphene7, 8, 9, 10, 11, 12, 13 as electrode materials have been developed and are capable of delivering high power density by electrochemical double layer charge storage. However, their energy densities, typically, 0.1–1.0 mW h cm −3 , are insufficient to meet the requirement of the reasonable operational time of microdevices.…”

Ultrafast‐Charging Supercapacitors Based on Corn‐Like Titanium Nitride Nanostructures

“…The very high power density of our TiN supercapacitors, 150 W cm −3 at an energy density of 0.30 mWh cm −3 , implies the capability of discharging within an extremely short time (14 ms). Detailed comparisons are listed in Table S1 (Supporting Information) 5, 6, 7, 8, 28, 29, 30, 31, 32. To our best knowledge, this is the first report of noncarbon supercapacitors without microconfiguration having such excellent performance in terms of ultrahigh power and energy densities.…”

All-solid-state supercapacitors on silicon using graphene from silicon carbide

“…[13][14][15] Graphene has been intensively investigated for various energy storage devices, [16][17][18] but the use of graphene in the all-solid-state supercapacitors has not been investigated sufficiently, [19][20][21][22][23][24] due to limitations in the availability of a large-scale high-quality graphene on the one hand, and to the difficulties related to the transfer of graphene powders to the substrate/device location, which results in cumbersome fabrication as well as poor reliability on the other hand. These challenges have urged the search for more reliable fabrication methods to obtain graphene on the substrate without further handling, e.g., transfer-free graphene on silicon substrates.…”

“…26 Finally, this approach could potentially be also extended to fabricate three-dimensional electrode structures, with a further enhancement in the energy density. 19 A 4-in. (100 mm in diameter) p-type Si(100) wafer with an epitaxial layer of cubic SiC ($500 nm in thickness) was purchased from NOVASIC (France) and used as received.…”