Single‐Atom Cadmium‐N₄ Sites for Rechargeable Li–CO₂ Batteries with High Capacity and Ultra‐Long Lifetime

Abstract

The rechargeable Li–CO2 battery shows great potential in civil, military, and aerospace fields due to its high theoretical energy density and CO2 capture capability. To facilitate the practical application of Li–CO2 battery, the design of efficient, low‐cost, and robust non‐noble metal cathodes to boost CO2 reduction/evolution kinetics is highly desirable yet remains a challenge. Herein, single‐atom cadmium is reported with a Cd‐N4 coordination structure enable rapid kinetics of both the discharge and recharge process when employed as a cathode catalyst, and thus facilitates exceptional rate performance in a Li–CO2 battery, even up to 10 A g−1, and remains stable at a high current density (100 A g−1). An unprecedented discharge capacity of 160045 mAh g−1 is attained at 500 mA g−1. Excellent cycling stability is maintained for 1685 and 669 cycles at 1 A g−1 and capacities of 0.5 and 1 Ah g−1, respectively. Density functional theory calculations reveal low energy barriers for both Li2CO3 formation and decomposition reactions during the respective discharge and recharge process, evidencing the high catalytic activity of single Cd sites. This study provides a simple and effective avenue for developing highly active and stable single‐atom non‐precious metal cathode catalysts for advanced Li–CO2 batteries.

Recent Advances in Rechargeable Metal–CO2 Batteries with Nonaqueous Electrolytes

“…The plot also reveals that Li−CO 2 batteries have attracted the most research attention, and as a result, the development of Li−CO 2 batteries has been most prominent. The recent work by Zhu et al 187 on Li−CO 2 batteries with Cd SAs-NC catalyst has been able to achieve a humongous full-cell discharge capacity exceeding 160 000 mAh/g at 500 mA/g with an impressive cycle life of 1685 at a current density of 1000 mA/g with a limited capacity of 1000 mAh/g. Other elements like K, Mg, and Al have also been gaining gradual attention.…”

“…The Li− CO 2 cells (1 M LiTFSI/DMSO electrolyte) fabricated by Xu et al delivered a high discharge capacity of 18652.7 mAh/g at a current density of 100 mA/g, a stable cycles number of 160 close to 1630 h of operation at 200 mA/g current density and 1000 mAh/g cutoff capacity, and a fairly low overpotential of 1.64 V at higher current densities at 1 A/g. Zhu et al 187 fabricated a novel cathode catalyst for secondary Li−CO 2 batteries by designing and constructing Cd single atoms (Cd SAs) immobilized on nitrogen-doped carbon (NC) with a Cd−N 4 moiety (Cd SAs/NC). Cd SAs/NC was prepared through a facile and easily scalable process, which involved impregnating carbon black with cadmium nitrate and polyacrylonitrile (PAN) and then calcinating the mixture at temperatures 500 °C, 600 °C, and 700 °C, respectively, under N 2 gas flow.…”

“…Zhu et al fabricated a novel cathode catalyst for secondary Li–CO 2 batteries by designing and constructing Cd single atoms (Cd SAs) immobilized on nitrogen-doped carbon (NC) with a Cd–N 4 moiety (Cd SAs/NC). Cd SAs/NC was prepared through a facile and easily scalable process, which involved impregnating carbon black with cadmium nitrate and polyacrylonitrile (PAN) and then calcinating the mixture at temperatures 500 °C, 600 °C, and 700 °C, respectively, under N 2 gas flow.…”

“…(h) Cycling performance of Cd SAs/NC_600-based Li–CO 2 cell at 1 A/g under a cutoff specific capacity of 500 mAh/g. Reprinted from ref , Copyright (2023) Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.…”

“…Zhu et al 187 achieved exceptional performance with Cd SAs/ NC_600 cathode catalyst-based Li−CO 2 batteries (1.2 M LiTFSI + 0.3 M LiNO 3 /DMSO electrolyte). The Cd SAs/ NC_600-based Li−CO 2 cell demonstrated a colossal full-cell discharge capacity of 160 045 mAh/g at a current density of 500 mA/g and a cutoff voltage of 2 V (Figure 15(a)).…”