One-step spray processing of high power all-solid-state supercapacitors.
Aqueous suspensions of multi-wall carbon nanotubes (MWNTs) in dilute H2SO4 were sprayed onto both sides of a Nafion membrane and dried to fabricate flexible solid-state supercapacitors. A single cell with MWNT-only electrodes had a capacitance of 57 F g(-1) per electrode at 2 mV s(-1) and 44 F g(-1) at 150 mV s(-1) but with low H(+) mobility. Cells with MWNT + ionomer hybrid electrodes showed higher H(+) mobility, and the electric double layer (EDL) capacitance increased to 145 F g(-1) at 2 mV s(-1) and 91 F g(-1) at 150 mV s(-1). The energy and power densities of one electrode charged to 1 V at 1 A g(-1) were 12.9 Wh kg(-1) and 3.3 kW kg(-1) respectively. Three solid-state supercapacitor cells connected in series charged to 3 V at 1 and 2 A g(-1) provided a device power density of 8.9 kW kg(-1) at 1 A g(-1) and 9.4 kW kg(-1) at 2 A g(-1), the highest for all-solid-state EDL supercapacitors.
Department of Materials, University of Oxford, Parks Road, Oxford, OX1 3PH, UK. ann.huang@materials.ox.ac.uk
Chun
C
Huang
Patrick S
PS
Grant
D025802:Electric Capacitance; D011211:Electric Power Supplies; D004867:Equipment Design; D019544:Equipment Failure Analysis; D008422:Materials Testing; D037742:Nanotubes, Carbon / Q000737:chemistry*; D013535:Suspensions
D037742:Nanotubes, Carbon; D013535:Suspensions