a, XRD pattern and SEM image (scale bar, 1 μm) of the crystal seeds used in the synthesis of LiXZM. Crystal seeds display a particle size of about 800 nm. b, XRD patterns of LiXZM before and after keeping for 1 year. c, SEM image of LiXZP (scale bar, 5 μm). d, XPS spectrum and Ag 3d spectra of LiXZP after the EIS experiment. After EIS, the XPS spectrum of LiXZP was conducted after scraping off the Ag current collectors from the LiXZP. No Ag could be detected in the Ag 3d spectrum, demonstrating that Ag could not participate in ion conduction as a mobile ion. The ionic conductivities of LiXZM and LiXZP were calculated using the formula σ = d/(R × S), in which the values of R (5.9 × 106 Ω for LiXZP, 11,720 Ω for LiXZM) were obtained from the fitted Nyquist plots, the values of d (1.5 × 10−2 cm for LiXZP, 5.0 × 10−4 cm for LiXZM) were from the SEM images in Fig. 1e, f, and the values of S (7.9 × 10−1 cm2 for LiXZP, 1.6 × 10−4 cm2 for LiXZM) corresponded to the adhesion area of silver electrodes for LiXZP (circle) and LiXZM (rectangle, stripped from the smooth stainless-steel substrate). Thus, the ionic conductivities were calculated to be 3.3 × 10−9 S cm−1 for LiXZP and 2.7 × 10−4 S cm−1 for LiXZM. e, f, EIS spectra (e) and the corresponding Arrhenius conductivity plots (f) of LiXZM at 25–200 °C in the frequency range of 1 MHz–10 Hz. According to the Arrhenius equation (σ = σ0exp(−Ea/kBT))34, the activation energy of conduction (Ea) is calculated to be 6.54 kJ mol−1. g, h, Current–time curves (g) and the corresponding electronic conductivity (h) of LiXZM at 25–500 °C. i, Results of scratch and Vickers hardness tests on LiXZM and LiXZP.