| AVS 60th International Symposium and Exhibition | |
| Thin Film | Monday Sessions |
| Session TF+EN-MoM |
| Session: | ALD for Energy |
| Presenter: | M.J. Young, University of Colorado, Boulder |
| Authors: | M.J. Young, University of Colorado, Boulder C.B. Musgrave, University of Colorado, Boulder S.M. George, University of Colorado, Boulder |
| Correspondent: | Click to Email |
Pseudocapacitive supercapacitors are a class of electrochemical storage device based on Faradaic charge transfer at the electrode/electrolyte interface. These supercapacitors exhibit higher energy density than electric double-layer capacitors and higher power density than Li ion batteries. Manganese oxide is a well-known pseudocapacitance material. In this work, MnO atomic layer deposition (ALD) was used to study manganese oxide as a pseudocapacitive supercapacitor. MnO ALD films were grown using sequential exposures of Mn(EtCp)2 and H2O on conducting stainless steel substrates . The MnO ALD films were then oxidized electrochemically to produce oxidized MnO1+x films. The electrochemical capacities of these films were measured using cyclic voltammetry. Capacities were found to increase from capacities of ~80 F/g for the as-deposited MnO ALD films to capacities of ~200 F/g after oxidation. These capacities after oxidation are comparable with the reported capacities of 150-250 F/g for α-MnO2 which is the crystalline phase of manganese oxide with the highest reported pseudocapacitance. The electrochemical capacity of manganese oxide is not purely a surface effect in contradiction with previous reports in the literature. The results suggest an optimal manganese oxide thickness for the highest specific capacity.