Fig. 4: Morphology and cycling stability of a Li anode assisted by TESM in ether-based electrolytes.

a, d Optical photographs of (a) Li foil protected by TESM and (d) bare Li foil after 20 cycles at 2 mA cm⁻² for 1 mAh cm⁻². b, c, e, f SEM images and corresponding enlarged areas of (b, c) TESM-protected Li and (e, f) unprotected Li, respectively. Scale bars, (b, e) 50 μm and (c, f) 20 μm. g Comparison of CEs with bare Cu, ESM-modified Cu, and TESM-modified Cu at various current densities. The fixed cycling capacity in each cycle is 1 mAh cm⁻². h The voltage profiles for the electrodes at 3 mA cm⁻². i The corresponding voltage hysteresis of electrodes with a current density of 3 mA cm⁻².