Extended Data Fig. 9: Long-term cycling performance of ASSLSBs.

a,b, Discharge–charge voltage profiles of the cell fitted with Li_5.5PS_4.5Cl_1.5 electrolyte (a) and LBPSI electrolyte (b) at a discharging/charging rate of 0.2C over different numbers of cycles (sulfur loading: 1.5 mg cm⁻²). c, Discharge–charge voltage profiles of the cell fitted with LBPSI electrolyte at a discharging/charging rate of 2C over 5,000 cycles (sulfur loading: 1.1 mg cm⁻²). d, Discharge–charge voltage profiles of the cell fitted with LBPSI electrolyte at a discharging/charging rate of 5C over 25,000 cycles (sulfur loading: 1.1 mg cm⁻²). e, Discharge–charge voltage profiles of the cell fitted with Li_5.5PS_4.5Cl_1.5 electrolyte at a discharging/charging rate of 5C over 10,000 cycles (sulfur loading: 1.1 mg cm⁻²) as a comparison. f, The evolution of stack pressure of ASSLSBs during discharge–charge cycles at 30 °C with LBPSI and Li_5.5PS_4.5Cl_1.5 electrolyte, respectively. Δp represents the change of stack pressure within one full discharge–charge cycle and \(\overline{\Delta p}\) is the average over five cycles. Both cells show apparent stack-pressure variations during cycling, indicating volume expansion and contraction of the electrodes; however, the average amplitude of pressure variation within one cycle for the cell using LBPSI is much lower than that with Li_5.5PS_4.5Cl_1.5 (\({\overline{\Delta p}}_{{\rm{LBPSI}}}=0.45\,{\rm{MPa}}\); \({\overline{\Delta p}}_{{\rm{LiPSCI}}}=1.08\,{\rm{MPa}}\)), which is indicative of a more profound buffering of the microscopic volume change in the case of LBPSI. g,h, Long-term cycling of the cell fitted with LBPSI at a discharging/charging rate of 8C (sulfur loading: 1.0 mg cm⁻²) (g) and corresponding discharge–charge voltage profiles at 25 °C (h). The cell was subjected to an activation process by cycling at 0.05–7C for several cycles. The cell exhibits a high capacity of 744 mAh g⁻¹ at 8C, with 78% capacity retention over 10,000 cycles.