<i>d</i> ‐Electrons of Platinum Alloy Steering CO Pathway for Low‐Charge Potential Li‐CO ₂ Batteries

Abstract

Abstract Aprotic Li‐CO 2 batteries suffer from sluggish solid‐solid co‐oxidation kinetics of C and Li 2 CO 3 , requiring extremely high charging potentials and leading to serious side reactions and poor energy efficiency. Herein, we introduce a novel approach to address these challenges by modulating the reaction pathway with tailored Pt d ‐electrons and develop an aprotic Li‐CO 2 battery with CO and Li 2 CO 3 as the main discharge products. Note that the gas‐solid co‐oxidation reaction between CO and Li 2 CO 3 is both kinetically and thermodynamically more favorable. Consequently, the Li‐CO 2 batteries with CoPt alloy‐supported on nitrogen‐doped carbon nanofiber (CoPt@NCNF) cathode exhibit a charging potential of 2.89 V at 50 μA cm −2 , which is the lowest charging potential to date. Moreover, the CoPt@NCNF cathode also shows exceptional cycling stability (218 cycles at 50 μA cm −2 ) and high energy efficiency up to 74.6 %. Comprehensive experiments and theoretical calculations reveal that the lowered d ‐band center of CoPt alloy effectively promotes CO desorption and inhibits further CO reduction to C. This work provides promising insights into developing efficient and CO‐selective Li‐CO 2 batteries.