From Spent Lithium-Ion Batteries to Low-Cost Li4SiO4 Sorbent for CO2 Capture

The huge consumption of fossil fuels leads to excessive CO2emissions,and its reduction has become an urgent worldwide concern. The combination ofrenewable energies with battery energy storage, and carbon capture, utilization, andstorage are well acknowledged as two major paths in achieving carbon neutrality.However, the former route faces the discard problem of a large amount of lithium-ionbatteries (LIBs) due to their limited lifespan, while it is costly to obtain effective CO2-capturing materials to put the latter into implementation. Herein, for thefirst time, wepropose a route to synthesize low-cost Li4SiO4as CO2sorbents from spent LIBs,verify the technical feasibility, and evaluate the CO2adsorption/desorptionperformance. The results show that Li4SiO4synthesized from the cathode withself-reduction by the anode graphite of LIBs has a superior CO2capacity and cyclicstability, which is constant at around 0.19 g/g under 15 vol % CO2after 80 cycles.Moreover, the cost of fabricating sorbents from LIBs is only 1/20-1/3 of theconventional methods. We think this work can not only promote the recycling of spent LIBs but also greatly reduce the cost ofpreparing Li4SiO4sorbents, and thus could be of great significance for the development of CO2 adsorption