climate change. [2] Many countries established legislations to limit the CO 2 emissions, targeting at carbon neutrality. [3] Meanwhile, efficient and clean battery systems are being developed. The lithium-ion battery (LIB) is the most successful and widely used system. [4] However, the relatively low energy density severely hindered the applications of LIBs. Recently, metalair batteries have attracted much attention due to their ultrahigh energy density. [5] However, most of them need to work in a pure oxygen environment. [6] Therefore, an energy-storage system directly utilizing CO 2 gas as redox medium is highly favorable.In 2013, Archer and co-workers proposed the concept of Li-CO 2 battery for CO 2 capture and energy storage, in which Li metal and CO 2 gas are the active materials in the anode and cathode side, respectively. [7] During discharge, Li + reacts with CO 2 to generate Li 2 CO 3 and carbon as discharge products, which is a CO 2 reduction reaction (CO 2 RR) process described as 4Li + + 3CO 2 + 4e − → 2Li 2 CO 3 + C. [8] In the reverse charging process, a CO 2 evolution reaction (CO 2 ER) occurs by decomposing Li 2 CO 3 into Li + and CO 2 gas. Many merits are identified for the Li-CO 2 battery system like the direct employing greenhouse gas of CO 2 and the high theoretical energy density of 1876 Wh kg −1 . [9] However, issues including but not limited to the large overpotential, poor cycling performance, and inferior rate capability significantly hinder the application of Li-CO 2 batteries. One dominating reason for these issues is the intrinsically sluggish kinetics of the CO 2 RR and CO 2 ER processes.Therefore, the key task for the practical application of Li-CO 2 batteries is to develop highly efficient catalysts toward the CO 2 RR and CO 2 ER. Large varieties of catalysts, such as carbon-based catalysts, [6,8a,b,10] single-metal-atom catalysts, [11] adjacent metal atoms catalyst, [12] nanostructured metal/alloy catalysts, [13] and transition metal compound catalysts [14] were developed for Li-CO 2 batteries to facilitate the CO 2 reduction and promote the decomposition of Li 2 CO 3 . Metallic ruthenium (Ru) and Ru-based materials is an important catalyst family for the CO 2 RR and CO 2 ER. [15] Ru catalyst has intrinsic advantage in The Li-CO 2 battery is a novel strategy for CO 2 capture and energy-storage applications. However, the sluggish CO 2 reduction and evolution reactions cause large overpotential and poor cycling performance. Herein, a new catalyst containing well-defined ruthenium (Ru) atomic clusters (Ru AC ) and single-atom Ru-N 4 (Ru SA ) composite sites on carbon nanobox substrate (Ru AC+SA @NCB) (NCB = nitrogen-doped carbon nanobox) is fabricated by utilizing the different complexation effects between the Ru cation and the amine group (NH 2 ) on carbon quantum dots or nitrogen moieties on NCB. Systematic experimental and theoretical investigations demonstrate the vital role of electronic synergy between Ru AC and Ru-N 4 in improving the electrocatalytic activity toward the C...

Aqueous zinc-based batteries (AZBs) attract tremendous attention due to the abundant and rechargeable zinc anode. Nonetheless, the requirement of high energy and power densities raises great challenge for the cathode development. Herein we construct an aqueous zinc ion capacitor possessing an unrivaled combination of high energy and power characteristics by employing a unique dual-ion adsorption mechanism in the cathode side. Through a templating/activating co-assisted carbonization procedure, a routine protein-rich biomass transforms into defect-rich carbon with immense surface area of 3657.5 m2 g−1 and electrochemically active heteroatom content of 8.0 at%. Comprehensive characterization and DFT calculations reveal that the obtained carbon cathode exhibits capacitive charge adsorptions toward both the cations and anions, which regularly occur at the specific sites of heteroatom moieties and lattice defects upon different depths of discharge/charge. The dual-ion adsorption mechanism endows the assembled cells with maximum capacity of 257 mAh g−1 and retention of 72 mAh g−1 at ultrahigh current density of 100 A g−1 (400 C), corresponding to the outstanding energy and power of 168 Wh kg−1 and 61,700 W kg−1. Furthermore, practical battery configurations of solid-state pouch and cable-type cells display excellent reliability in electrochemistry as flexible and knittable power sources.

Main group metals are routinely considered as catalytically inactive hence never employed for optimizing the lithium-sulfur electrochemistry. Herein, density function theory calculations reveal that atomically dispersed tin on nitrogen doped...

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This topical review focuses on the distinct role of carbon support coordination environment of single atom catalysts (SACs) for electrocatalysis. The article begins with an overview of atomic coordination configurations in SACs, including a discussion of the advanced characterization techniques and simulation used for understanding the active sites. A summary of key electrocatalysis applications is then provided. These processes are oxygen reduction reaction (ORR), oxygen evolution reaction (OER), hydrogen evolution reaction (HER), nitrogen reduction reaction (NRR) and carbon dioxide reduction reaction (CO2RR). The review then shifts to modulation of the metal atom‐carbon coordination environments, focusing on nitrogen and other non‐metal coordination through modulation at the first coordination shell and modulation in the second and higher coordination shells. Representative case studies are provided, starting with the classic four‐nitrogen‐coordinated single metal atom (M‐N4) based SACs. Bimetallic coordination models including homo‐paired and hetero‐paired active sites are also discussed, being categorized as emerging approaches. The theme of the discussions is the correlation between synthesis methods for selective doping, the carbon structure – electron configuration changes associated with the doping, the analytical techniques used to ascertain these changes, and the resultant electrocatalysis performance. Critical unanswered questions as well as promising underexplored research directions are identified.This article is protected by copyright. All rights reserved