Spent ternary lithium-ion batteries-derived NiCo/MnO@CC interfacial catalyst Modulates Li2CO3 Deposition in Li-CO2 Batteries

Abstract

Herein, spent ternary lithium-ion batteries (NCM) are upcycled into NiCo/MnO interfacial catalyst for Li-CO2 batteries. Integrated theoretical calculations and experimental analyses reveal that the interfacial affinity facilitates CO2 adsorption and induces smallsized and uniform Li2CO3 deposition, endowing the catalyst with reduced polarization and 1200 h cycling stability.Contemporary energy storage has been reshaped by lithium-ion batteries. Yet their insufficient energy density increasingly restricts their application in future energy systems. 1 Considerable interest has turned to metal-gas rechargeable batteries, which features an energy density 5-10 times higher than traditional lithium-ion batteries. 2,3 Among them, Li-CO2 batteries, based on the mainstream reaction of 4Li + 3CO2 ↔ 2Li2CO3 + C, stand out as a potential candidate owing to their large theoretical energy density (1876 Wh kg -1 ) as well as their distinctive ability to couple energy storage with CO2 capture and fixation, thereby storing electricity derived from clean energy sources and contributing to sustainability and carbon neutrality. 4,5 Nonetheless, sluggish CO2 redox kinetics at cathodes, primarily from the intrinsic inertness of CO2, poses a severe obstacle to practical application. 6 More importantly, the thermodynamically stable and electronically insulated discharge product Li2CO3 tends to accumulate uncontrollably on the catalyst surface, passivating the electrode, blocking active sites and hindering CO2 transport. This undesirable deposition behavior inevitably leads to low energy efficiency, high overpotential, and a short cycle life. 7,8 Recent studies demonstrate that these problems can be modulated through altering gas atmosphere, the catalyst surface chemistry and the size of active species.