An integrated cathode-electrolyte architecture with Cu dual active-sites for all-solid-state Li–CO2 batteries

All-solid-state Li–CO2 batteries are limited by sluggish interfacial CO2 redox kinetics and the incomplete decomposition of insulating Li2CO3 at rigid solid-solid-gas interfaces. Here, we report an integrated cathode-electrolyte architecture in which copper atomic clusters and single atoms are co-anchored on freestanding N-doped carbon nanotubes and coupled with a succinonitrile/Li1+xAlyGe2-y(PO4)3-based solid-state electrolyte. The conformal ion-conducting phase and conductive nanotube scaffold provide coupled pathways for Li+, electrons and CO2 at the cathode interface. Electronic coupling between the copper atomic clusters and single atoms induces charge transfer from the former to the latter (~0.457 e−), rendering the Cu cluster sites partially cationic and facilitating the activation of carbonate intermediates. This dual-site configuration changes the discharge pathway and lowers the reaction energy of the rate-determining step to 2.412 eV. The assembled battery delivers a discharge capacity of 21356 mAh g−1 at 200 mA g−1 and operates for 260 cycles (>1000 h) at 500 mA g−1 with an energy efficiency of 78%. This work provides an interfacial design strategy for solid-state Li–CO2 batteries by coupling continuous transport pathways with electronically regulated dual Cu active sites. Stimuli responsive assemblies can offer precise control over behaviour, but use of gases for this control is rare. Here, the authors report the use of carbon dioxide for tuneable nanoparticle response, directed by changes in peptide structure.