Rational catalyst structural design to facilitate reversible Li-CO2 batteries with boosted CO2 conversion kinetics

Lithium-CO2 batteries (LCBs) are regarded as a promising energy system for CO2 drawdown and energy storage capability which has attracted widespread interest in carbon neutrality and sustainable societal development. However, their practical application has been limited by slow kinetics in catalytic reactions and poor reversibility of Li2CO3 products which leads to the issue of a large overpotential, low energy efficiency and poor reversibility. Herein, an efficient catalyst design and synthesis strategy is proposed to overcome the abovementioned bottleneck. Through an electrical joule heating procedure, Pt with random crystal orientations is converted into a 3D porous Pt catalyst with preferred (111) crystal orientation within seconds, exhibiting enhanced CO2 conversion kinetics with superior electrochemical performance. This includes ultralow overpotential (0.45 V), fast rate charging (up to 160 mu A cm-2) and high stability (over 200 cycles under 40 mu A cm-2). A proof-of-concept stacked Li-CO2 pouch cell, with stable operation under practical current density is demonstrated, indicating significant potential for large-scale operations. This bottom-up design of efficient catalysts and synthesis strategy offers a rapid and cost-effective approach to maximizing catalytic sites for CO2 conversion under restricted catalyst loading, showcasing its versatility across a broad spectrum of catalyst-based energy conversion and storage systems.

Automated summary

This study proposes an efficient catalyst design and synthesis strategy for lithium-CO2 batteries, which converts Pt into 3D porous Pt catalyst with preferred crystal orientation. The catalyst exhibits enhanced CO2 conversion kinetics and superior electrochemical performance. The demonstration of a proof-of-concept stack Li-CO2 pouch cell showcases the potential for large-scale operations.