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Highly efficient mixed H + /e − /O 2− triple conducting air electrodes are indispensable for improving the electrochemical performance of protonic ceramic fuel cells and electrolysis cells (PCFC/ECs) operating at intermediate temperatures. This study demonstrates that single perovskite-type La 0.8 Sr 0.2 Co 1-x Ni x O 3-δ families (LSCN, x = 0−0.3) are efficient H + /e − /O 2− triple conductors due to a pronounced hydration ability at elevated temperatures with a related enthalpy of −107 kJ mol −1 . Thermogravimetry confirmed that the oxides were capable of a 0.01 mole fraction proton uptake at 600 °C and p H2O of 0.023 atm. Reversible protonic ceramic cells were fabricated using these oxides as an air electrode and exhibited promising performance with a peak power density of 0.88 W cm −2 in fuel cell mode and an electrolysis current of 1.09 A cm −2 at a thermal neutral voltage in electrolysis cell mode at 600 °C. Impedance analysis confirmed that the polarization resistance of the La 0.8 Sr 0.2 Co 0.7 Ni 0.3 O 3-δ cell was 0.09 Ω cm 2 under an open circuit potential at 600 °C, which is much smaller than the polarization resistances reported for cells with a single or double perovskite-type triple conductor. The current results indicate that mixed H + /e − / O 2− triple phase conducting LSCN oxides are promising air electrodes for protonic ceramic cells operating in the intermediate temperature region at approximately 600 °C.

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The density functional theory is used to study the effect of the external biaxial strain on the adsorption and diffusion of Li on the graphyne as an anode material in the Li-ion battery (LIB). The increasing adsorption energy of Li on graphyne appears with the larger external biaxial strain. The Li capacity of the Li6C6 configuration for graphyne reaches 2233 mA h/g under the 12% strain, which is six times that of graphite (372 mA h/g) and two times that of graphyne without strain (1117 mA h/g). The average open-circuit voltage is 0.50 V, which is about 0.14 eV lowered by the 12% strain and is ideal for LIBs. Li on the graphyne can diffuse easier under the 12% strain than that without strain. Furthermore, the diffusion coefficient for Li on the multilayer graphyne under the 12% strain at 300 K is fivefold of the value without strain. Excellent performances of Li capacity and Li diffusion make graphyne under the 12% strain a promising anode material for LIBs.

Protonic solid oxide steam electrolysis cells (P-SOECs) based on BaZrxCe0.8-xYb0.1Y0.1O3 proton conductors are promising to produce “green” hydrogen from renewable energy at intermediate temperatures. Herein, we demonstrate that the electrolysis...