Nickel—cobalt supercapacitors and methods of making same
AssigneeBattelle Memorial Institute
InventorsSteven M. Risser, Vincent D. McGinniss, Bing Tan, Kevin B. Spahr, Homero Casteneda-Lopez
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Abstract
Improved capacitors containing novel electrodes are described. One electrode composition comprises mixed metal oxides of the transition metals nickel and cobalt in a molar ratio of 0.5:1 or greater, and optionally containing a binder and carbon nanotubes. The resulting capacitors can be characterized by superior properties including higher specific capacitance values at higher voltage scan rates than the prior art. Methods of forming the electrodes that produce superior results are also described.
Claims24
A capacitor comprising:
- an electrode, and wherein the electrode comprises:
- Ni and Co in a molar ratio of greater than 0.5:1;
- wherein the electrode comprises no more than 5 mass % TiO2;
- and further possessing one or more of the following characteristics:
- (a) the electrode comprises a specific capacitance of at least 450 F/g·cm2 if measured at a voltage scan rate of 20 mV/s in 1M KOH aqueous electrolyte;
- or
- (b) absorbance in the IR spectrum of an OH stretch that is at least as intense as other absorptions in the region from 1000 to 4000 cm−1.
A method of making an electrode, comprising:
- forming a composition comprising Ni and Co in a molar ratio of 0.5:1 to 6:1;
- reacting the composition to form a gel comprising Ni and Co in a molar ratio of 0.5:1 to 6:1;
- drying the gel to obtain a powder comprising Ni and Co in a molar ratio of 0.5:1 to 6:1;
- and
- compacting the powder to form an electrode.
Dependencies are inferred from the claim text.