A Simple and Fast Electrochemical CO₂ Sensor Based on Li₇La₃Zr₂O₁₂ for Environmental Monitoring

Abstract In the goal of a sustainable energy future, either the energy efficiency of renewable energy sources is increased, day‐to‐day energy consumption by smart electronic feedback loops is managed in a more efficient way, or contribution to atmospheric CO₂ is reduced. By defining a next generation of fast‐response electrochemical CO₂ sensors and materials, one can contribute to local monitoring of CO₂ flows from industrial plants and processes, for energy management and building control or to track climate alterations. Electrochemical Li⁺‐garnet‐based sensors with Li₇La₃Zr₂O₁₂ solid electrolytes can reach notable 1 min response time at lowered operation temperatures to track 400–4000 ppm levels of CO₂ when compared with state‐of‐the‐art NASICON‐based sensors. By using principles of redefining the electrode electrochemistry, it is demonstrated that Li_6.75La₃Zr_1.75Ta_0.25O₁₂ can be used to alter its classic use as energy‐storage function to gain additional functions such as CO₂ tracking.