Inorganic perovskites exhibit many important physical properties such as ferroelectricity, magnetoresistance and superconductivity as well their importance as energy materials. Many of the most important energy materials are inorganic perovskites and find application in batteries, fuel cells, photocatalysts, catalysis, thermoelectrics and solar thermal. In all these applications, perovskite oxides, or their derivatives offer highly competitive performance, often state of the art and so tend to dominate research into energy material. In the following sections, we review these functionalities in turn seeking to facilitate the interchange of ideas between domains. The potential for improvement is explored and we highlight the importance of both detailed modelling and in situ and operando studies in taking these materials forward.

Recently hybrid direct carbon fuel cells (HDCFC) has attracted great attention, combining the advantages of solid oxide fuel cells and molten carbonate fuel cells, to convert energy of carbon to electricity directly without chemical combustion. In this work, three processed carbon fuels including activated carbon, carbon black and graphite have been employed to investigate influence of the chemical and physical properties of carbon on the HDCFC performance in different anode atmospheres at 650-800 °C. The results reveal that the electrochemical activity is strongly dependent on crystalline structure, thermal stability and textural properties of carbon fuels. The activated carbon samples demonstrate a better performance with a peak power density of 326 mW cm-2 in CO2 at 750 °C, compared to 147 and 59 mW cm-2 with carbon black and graphite samples, respectively. The impedance spectra indicates the polarization resistance plays a more dominated role in the cell performance. When replacing N2 by CO2 purge gas, the power density is the strongly temperature dependent due to the Boudouard reaction.

Iron-based electrode materials are widely investigated for robust and high-performance SOCs because of their low-cost and the appropriate valence stability of Fe–O bond to exhibit excellent redox activity across a wide range of electrode functions.

Biomass is expected to play a significant role in power generation in the near future. With the uprising of carbon fuel cells, hybrid direct carbon fuel cells (HDCFCs) show its intrinsic and incomparable advantages in the generation of clean energy with higher efficiency. In this study, two types of biomass treated by physical sieve and pyrolysis from raw sawdust are investigated on an anode-supported HDCFC. The structure and thermal analysis indicate that raw sawdust has well-formed cellulose I phase with very low ash. Electrochemical performance behaviors for sieved and pyrolyzed sawdust combined with various weight ratios of carbonate are compared in N2 and CO2 purge gas. The results show that the power output of sieved sawdust with 789 mWcm-2 is superior to that of pyrolyzed sawdust in CO2 flowing, as well as in N2 flowing. The anode reaction mechanism for the discrepancy of two fuels is explained and the emphasis is also placed on the modified oxygen-reduction cycle mechanism of catalytic effects of Li2CO3 and K2CO3 salts in promoting cell performance.