Fig. 1

Schematic of Li-CO2 battery structure"

Fig. 2

SEM images of CNTs cathodes in different states： pristine (a)；after discharge at different current densities: 50 (b), 100 (c), and 150 mA/g (d) with a cut-off capacity of 1000 mAh/g[15]；(e) Adsorption energies of graphene, graphitic-N, pyrrolic-N, and pyridinic-N for CO2, Li, and Li2CO3[16]；(f) Schematic for the preparation of B-NCNT cathode by floating catalyst chemical vapor deposition[13]；(g), (h) SEM and (i) TEM images of 3D NCNT/G[17]; (j) The charge-discharge overpotential as a function of the adsorption energy of *CO intermediate[20]"

Fig. 3

(a) Schematic of the reaction mechanism of Li-CO2 batteries and (b), (c) in-situ SERS spectra with and without Ru catalysts[11]；(d) Finite difference time domain simulations and schematics of the charge carrier migration of TNAs and TNAs@AgNPs. E0 and E represent the intensities of the incident and localized electric field, respectively；(e) Mechanism of the dual-field assisted Li-CO2 battery[26]；HRTEM images of Ru NPs (f) and Ni/Ru HNPs (g) in Ru(10-10) and Ru(0002)；(h) The Projected Density of State of Ru 4d orbital on Ni/Ru (0002) and pristine Ru (0002) (Dashed lines indicate the d-band centers)[29]"

Fig. 4

(a) The planar-averaged charge density difference (Δρz) for the Fe2O3/Cu2O sample; (b) Schematic diagram of the catalytic mechanism of Fe2O3/Cu2O/Cu[36]；Mo 3d XPS spectra after 1st discharge (c) and 1st recharge (d) of Mo2N@HsGDY[37]；SEM image (e) and illustration (f) of V-MoS2/Co9S8@CP with MoS2 vertically grows on Co9S8 with an interface along the edge；(g) Gibbs free energy changes at the rate-determining step of MoS2 basal plane, MoS2 edge and Co9S8[38]"

Fig. 5

(a) Atomic-resolution STEM image, (b) Fe K-edge XANES and (c) EXAFS of Fe-ISA/N,S-HG[40]；(d) Schematic illustrations of Fe-N-C catalysts[42]；Work function profiles of (e) Co4N (111) and (f) Cu-Co4N (111) surface[44]；(g), (h) SEM images of Runp-NC@rGO (Nanoparticle) and Ruh-NC@rGO (Single-Atom) discharged cathode[43]；(i) Li2C2O4 adsorption configurations on oxygen group-doped Mn-N4 sites and on N,O-doped graphene[45]"

Fig. 6

(a) CV curves of Li-CO2 batteries with LiBr and (b) schematic diagram of the charging mechanism of Li-CO2 battery；(c) Charge-discharge polarization curves of Li-CO2 batteries with addition of LiBr as RMs[46]；(d) Mechanism of Cu(I)-RMs-mediated CO2RR[48]；(e) Mechanism diagram of RM(II)-BTC-mediated Li2C2O4 product generation[49]"

Fig. 7

Comparison of the electrochemical performance of Li-CO2 battery based on partial cathode catalysts"