In this modern era, energy devices have become an important part of our daily life. Various types of energy conversion devices have been developed to meet the current energy demands. Semiconductor anode (CdZnO) has been synthesized by the sol-gel method and lattice constants and the band gap results have been compared experimentally and theoretically. XRD results show that Cddoped ZnO shifts the peaks toward the lower angles, increases the lattice parameters, and decreases the crystallite size (48 nm). Microstructure of Cd-doped ZnO shows the agglomerations of particles, found in the shape of cubes, hexagons, and dumbbell shapes with diameter in the range of 2-7 µm. The experimentally obtained conductivity of CdZnO is 0.142 S/cm at 550 • C. The electrochemical impedance spectroscopy shows the decreased resistance with an increase in temperature. The doped system shows a maximum open circuit voltage of 0.95 V and performance of 0.52 W/cm 2 at 550 • C.

The efficiency of direct carbon fuel cells is higher than that of solid oxide fuel cells. The direct carbon fuel cell transforms chemical energy into electrical energy. In this work, the La0.4Sr0.6Mn x Ti1–x O3−δ (x = 0.02, 0.04, 0.06, 0.08) anode material has been synthesized by the combustion method to examine the device performance. X-ray analysis confirmed the single-perovskite cubic structure with an average crystalline size of 80 nm. An electrical conductivity of 2.1 S cm–1 and fuel cell performance of 100 mW cm–2 at 600 °C are measured with sub-bituminous fuel. Theoretical results describe the minor contribution of manganese (Mn) in the valence band and the major one in the conduction band, and with minimum energy, the Mn electrons may jump in the conduction band. Moreover, density functional theory confirmed that with an increase in the Mn concentration, Mn and Ti energy states appear at the Fermi level, which reveals that the conductivity of the compound has improved, agreeing with the experimental results that the Mn concentration led to the enhancement of the conductivity.