A Simple and Fast Electrochemical CO2 Sensor Based on Li7 La3 Zr2 O12 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 Li₇ La₃ Zr₂ O₁₂ 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_6.75 La₃ Zr_1.75 Ta_0.25 O₁₂ can be used to alter its classic use as energy-storage function to gain additional functions such as CO₂ tracking.

Keywords: LLZO; Li-garnet; Li-ion conductors; carbon dioxide sensors; electrochemical sensors; environmental monitoring.