A comprehensive overview of the electrochemical mechanisms in emerging alkali metal–carbon dioxide batteries

Abstract

Alkali metal–carbon dioxide (Li/Na/K‐CO2) batteries are emerging electrochemical energy storage technologies in the context of the energy crisis and the urgent demand for carbon neutrality. Alkali metal–CO2 batteries offer a new strategy for CO2 fixation and utilization, and thus has been receiving considerable attention in recent years. Considerable progress has been achieved since alkali metal–CO2 batteries were invented, especially in terms of development of new electrode materials, and yet, research is lacking on the underlying mechanisms of the systems. This is the first typical review focusing on the electrochemical mechanisms of metal–CO2 batteries that summarizes the current understanding of and provides insights into the thermodynamic reaction pathways, the kinetic characteristics, and the crucial factors determining the reaction mechanisms in alkali metal–CO2 batteries. The review starts with the fundamental concepts of alkali metal–CO2 batteries, followed by a comprehensive discussion of the working mechanisms on cathodes and anodes. Moreover, the operation mechanisms of state‐of‐the‐art electrolytes, including liquid and (quasi‐)solid‐state electrolytes, are also described. Finally, we identify the unsolved problems in current alkali metal–CO2 batteries and propose potential topics for future research.

Review on CO2 Management: From CO2 Sources, Capture, and Conversion to Future Perspectives of Gas-Phase Electrochemical Conversion and Utilization

“…From an encouraging perspective, looking at CO 2 as an environmental problem can be transformed into an economic opportunity through current progress in CO 2 utilization. More recently, galvanic cells based on CO 2 reduction in the cathode, instead of O 2 , in rechargeable Li/CO 2 batteries, − CO 2 /H 2 fuel cells, − or even CH 4 /CO 2 –O 2 fuel cells , have been developed. These ideas fascinatingly provide dual beneficial effects: decreasing CO 2 in the atmosphere while at the same time generating electricity.…”

A rechargeable liquid metal–CO2 battery for energy storage and CO2 reduction to carbon

“…6,7 Moreover, the existing MCBs discharge resistive solids such as carbonates, oxides, and carbon at the gas (CO 2 )/electrolyte/electrode triplephase boundaries (TPBs) to hinder the mass and electric charge transfer in charging and discharging processes. 8,9 Thus, discovering innovative heterogeneous electrochemical catalysts and catalyst architectures for enhancing the cathodic CO 2 R reaction kinetics and transport efficiency has been the primary focus of MCB research. Various catalysts made of Ptgroup metals (PGMs) and Au, functionalized composite nanomaterials, and nanostructured transition metals/alloys have been reported to reduce the reaction overpotentials.…”

“…6,7 Moreover, the existing MCBs discharge resistive solids such as carbonates, oxides, and carbon at the gas (CO 2 )/electrolyte/electrode triple-phase boundaries (TPBs) to hinder the mass and electric charge transfer in charging and discharging processes. 8,9…”

Synergistic Effect of CO2 in Accelerating the Galvanic Corrosion of Lithium/Sodium Anodes in Alkali Metal–Carbon Dioxide Batteries

“…This direct electrochemical recycling of CO 2 in alkali metal–CO 2 batteries could not only deliver high theoretical specific energy density but also possess the distinctive merits of high efficiency and environmental friendliness in CO 2 recyclability. , Although the alkali metal–CO 2 battery technology has received increasing attention, its further practical application is still impeded by the inferior reversibility, limited cycle life, and low energy efficiency during battery operation. Tremendous efforts have been devoted recently to address these issues by investigating intensively the fundamental electrochemical redox processes and the governing degradation factors of the alkali metal–CO 2 batteries. − Fortunately, with a profound understanding of the underlying reaction mechanisms, the past few years have witnessed considerable progress on the development of highly efficient catalysts and optimized electrolytes in improving the overall alkali metal–CO 2 battery performance. , Nevertheless, the uncontrolled and serious alkali anode corrosion/pulverization behaviors still pose significant challenges for their further development …”