Author(s):
S S Gaur, Ravindra Singh, Abha Shukla

Abstract:
The global green energy demand has led to the development of the Hydroelectric cell (HEC). It is a device that generates electricity through water dissociation on oxygen deficient nanoporous metal oxide surfaces. The dissociation of water produces hydronium and hydroxide ions which undergo electrochemical reactions at the electrodes, generating emf and current. This study investigates the performance of pristine and lithium doped tantalum oxide based HEC. Experimental results demonstrate that doping Ta2O5 with lithium significantly enhances current and power output compared to the undoped sample. The pure Ta2O5 based HEC produced a short circuit current (Isc) of 0.3 mA and an open circuit voltage (Voc) of 1.23 V compared to the Li doped Ta2O5 HEC. It exhibited a substantially higher short circuit current of 2.4 mA and an open circuit voltage of 0.966 V. The doped sample based HEC delivered a power output of ~ 0.25 mW in comparison to the undoped sample which delivered a maximum power output of ~ 0.074 mW. Electrochemical impedance spectroscopy (EIS) revealed that lithium doping reduced the charge transfer resistance and promoted ionic conduction in the doped sample, as evidenced by the extended Warburg diffusion tail in the Nyquist plot. Lithium doping facilitated more efficient water dissociation and ion transport in the sample. The increase power output in the Li doped sample has been attributed to the increased oxygen vacancies, surface defects and nano porosity induced by lithium.

Pages: 1034-1040

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