The fossil fuel crisis and global warming are becoming more and more severe in this century, while the exploration of human survival on Mars is being pushed forward steadily. Hence, it is meaningful to effectively utilize CO2, the main greenhouse gas and a major component of the Martian atmosphere. Due to their high capacity and ability to capture CO2, Li–CO2 batteries have received much attention. However, there are problems that still need to be solved relating to Li–CO2 batteries, including the instability of the electrolyte and the non-negligible polarization caused by the formation and decomposition of Li2CO3. To address these issues, an all-solid-state Li–CO2 battery, which uses RuO2 nanoparticles combined with single-walled carbon nanotubes (SWCNTs) as the cathode material and a sodium super ionic conductor (NASICON)-type ceramic solid electrolyte, Li1.5Al0.5Ge1.5(PO4)3 (LAGP), has been developed and it operates over a broad temperature range. Under a pure CO2 atmosphere, this well-designed battery shows a discharge capacity of 2499 mA h g−1 and a charge capacity of 2137 mA h g−1 in the first cycle at 60 °C, and stable cycling performance over 30 cycles under a capacity limitation of 500 mA h g−1 at a current density of 50 mA g−1. This result enhances the possibility of the utilization of the Li–CO2 battery in the future.
Moxing Cheng,Haoyun Sheng,Yin’an Zhu,Ziqi Tian,Yichao Lin
The development of highly active and durable catalysts for the acidic oxygen evolution reaction (OER) is urgently needed to accelerate reaction kinetics and reduce energy barriers. Herein, we propose to tune the local electronic structure in RuO 2 via yttrium ion (Y 3+ ) doping to facilitate the OER process following oxide path mechanism (OPM). The electron-deficient of Y 3+ redistributes local charge density, strengthens metal–oxygen bonds to suppress lattice degradation. Moreover, the incorporation of larger Y 3+ radius reduce the Ru–Ru distance, and thereby benefits O–O coupling. The optimized Y 0.11 Ru 0.89 O 2−δ catalyst exhibits an exceptionally low overpotential of 195 mV at 10 mA cm −2 for acidic OER and operates stably for 250 h at 100 mA cm −2 in a PEM electrolyzer. Theoretical investigations reveal that Y–O–Ru structure effectively modifies the chemical environment and optimizes the atomic configuration of active sites. This study establishes electron-deficient, large-radius dopants as an effective strategy for designing efficient and durable acidic OER catalysts, enhancing RuO 2 performance.