Based on a systematic investigation on aprotic Li-CO 2 electrochemistry, we design a flexible strategy for either CO 2 fixation or energy storage. Typically, CO 2 can be fixed into carbon species through a rechargeable/irreversible electrochemical process. Moreover, using a specific catalyst, the aprotic Li-CO 2 battery system can be realized via a reversible cycle. The proof of concept revealed in this study provides strong theoretical support for the practical design of both CO 2 fixation techniques and renewable energy storage devices.

The application of Ru nanoparticles as a cathode catalyst significantly promotes the reversibility of Li–CO2 batteries.

Conventional cathodes of Li-ion batteries mainly operate through an insertion-extraction process involving transition metal redox. These cathodes will not be able to meet the increasing requirements until lithium-rich layered oxides emerge with beyond-capacity performance. Nevertheless, in-depth understanding of the evolution of crystal and excess capacity delivered by Li-rich layered oxides is insufficient. Herein, various in situ technologies such as X-ray diffraction and Raman spectroscopy are employed for a typical material Li Ni Mn O , directly visualizing O O (peroxo oxygen dimers) bonding mostly along the c-axis and demonstrating the reversible O /O redox process. Additionally, the formation of the peroxo OO bond is calculated via density functional theory, and the corresponding OO bond length of ≈1.3 Å matches well with the in situ Raman results. These findings enrich the oxygen chemistry in layered oxides and open opportunities to design high-performance positive electrodes for lithium-ion batteries.

No abstract