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Solid oxide cell technologies play a pivotal role in the realm of renewable energy storage, guiding us through the journey toward decarbonization. Understanding how electrocatalytic materials behave under high‐temperature conditions is an absolute necessity to push these technologies forward. Operando spectroscopic investigations, such as near‐ambient pressure X‐ray photoelectron spectroscopy (NAP–XPS), offer insights into the chemical nature of active working electrodes, including the dynamic response of redox states and adsorbate chemistry to changing electrochemical conditions. Mixed ceramic–metallic electrodes exhibit a limited region with electrochemically active triple‐phase‐boundary (TPB) sites, which are located close to the electrolyte/electrode interface. To monitor this specific region spectroscopically, metallic (Ni) and bimetallic (NiCu) network‐like structures are synthesized on a yttria‐stabilized zirconia electrolyte and the electrochemical state and performance are studied by using operando NAP–XPS. In the experiments, the surface oxidation states under different polarizations are revealed, the gas composition dependent Nernst shift is confirmed, electrocatalytic activities are unraveled, and hydrogen evolution is correlated with the applied potential. The findings demonstrate, the effectiveness of thin‐film model cells with spectroscopically accessible TPB regions for probing interfacial states and electrochemical processes. The obtained fundamental knowledge can provide valuable insights for the advancement of renewable energy storage technologies. [ABSTRACT FROM AUTHOR]

NaTi2(PO4)3 (NTP) is known as a promising insertion‐type anode material for aqueous and non‐aqueous sodium‐ion batteries (SIBs), due to its NASICON‐type open 3D framework which makes a zero‐strain insertion mechanism possible. NTP is considered to be an environmentally friendly, low‐cost and high safety material. However, the electrochemical performance of NTP is limited due to its poor electrical conductivity. In this work a solvothermal synthesis method is used to synthesize NTP with a nanocube (NC) morphology. In a one‐step synthesis rutile titanium dioxide (TiO2) and carbon coating of NTP are achieved (NTP/C‐RT), simultaneously, which significantly improves the poor electrical conductivity of NTP. Additional rutile coating is used to further improve the electrochemical performance compared to simple carbon coating. Rate capabilities of 301 mAh/g are achieved for NTP/C‐RT compared to 248 mAh/g for NTP/C at 0.1 C. That is, to the best of our knowledge, the highest gravimetric capacity reported for SIBs using NTP as anode material up to now. The results prove that NTP, which is itself already a promising anode material for SIBs, can be further enhanced with a combined approach of NC morphology, carbon and rutile coating, leading to superior capacities, higher than anywhere else reported in literature. [ABSTRACT FROM AUTHOR]

A versatile multifunctional laboratory-based near ambient pressure x-ray photoelectron spectroscopy (XPS) instrument is presented. The entire device is highly customized regarding geometry, exchangeable manipulators and sample stages for liquid- and solid-state electrochemistry, cryochemistry, and heterogeneous catalysis. It therefore delivers novel and unique access to a variety of experimental approaches toward a broad choice of functional materials and their specific surface processes. The high-temperature (electro)catalysis manipulator is designed for probing solid state/gas phase interactions for heterogeneous catalysts including solid electrolyzer/fuel cell electrocatalysts at pressures up to 15 mbar and temperatures from room temperature to 1000 °C. The liquid electrochemistry manipulator is specifically designed for in situ spectroscopic investigations of polarized solid/liquid interfaces using aqueous electrolytes and the third one for experiments for ice and ice-like materials at cryogenic temperatures to approximately −190 °C. The flexible and modular combination of these setups provides the opportunity to address a broad spectrum of in situ and operando XPS experiments on a laboratory-based system, circumventing the limited accessibility of experiments at synchrotron facilities. [ABSTRACT FROM AUTHOR]