Sn-O dual-doped Li-argyrodite electrolytes with enhanced electrochemical performance

High Air Stability and Excellent Li Metal Compatibility of Argyrodite‐Based Electrolyte Enabling Superior All‐Solid‐State Li Metal Batteries

“…It may be relevant to the lattice tolerance of the argyrodite‐based crystal structure and excessive doping amount of Bi 2 O 3 may destroy the ion conduction network of electrolyte, which is also observed in other SSEs constructing based on the PS 4 3− tetrahedra. [ 32,41 ] The corresponding activation energies (Ea) of Li 6+2 x P 1− x Bi x S 5−1.5 x O 1.5 x Cl SSEs shown in Figure 2c present a converse tendency compared to that of the ionic conductivity evolution in Figure 2b. The calculated Ea of the Li 6.04 P 0.98 Bi 0.02 S 4.97 O 0.03 Cl SSEs is 0.261 eV, which is lower than that of Li 6 PS 5 Cl (0.289 eV).…”

“…The change of cell volume is the result of competition that the replacement of P 5+ ions by Bi 3+ with larger ionic radius (R (Bi 3+ ) :103 pm > R (P 5+ ) :38 pm) would contribute to increasing the expansion of the unit cell, whereas S 2− partially substituted by O 2− (R (O 2− ) :140 pm < R (S 2− ) :184 pm) would lead to the contraction of the lattice volume. [22,32] Obviously, the increased cell volume indicates that Bi 3+ doping has a greater effect on the lattice parameters than O 2− doping. In addition, the aliovalent replacement of P 5+ ions by Bi 3+ would increase the Li + ion concentration in the particular unit cell to maintain electric neutrality.…”

Recent progress of sulfide electrolytes for all-solid-state lithium batteries

“…This type of interphase plays a similar role as the SEI. For example, Li 6 PS 5 Cl and Li react to form Li 2 S, Li 3 P and LiCl [60,116] . The resistance of Li-Li symmetric cells incorporated with Li 6 PS 5 Cl does not continue to increase because the reaction products of Li and Li 6 PS 5 Cl are rather stable against Li.…”

“…Moreover, accompanied by the success of Li 3 N-rich SEI in LMBs using organic electrolytes, Liu et al [60] substituted partial Cl atoms in Li 6 PS 5 Cl with N atoms. On this basis, an in-situ formed Li 3 N-rich interphase was introduced.…”

The crucial role of oxygen substitution in argyrodite solid electrolytes from the bulk to the surface under atmospheric conditions

“…[40][41][42] Furthermore, partially O-doped Li 6 PO 0.3 S 4.7 Br was recently introduced to enhance stability, and this O substitution for S in Li 6 PO n S 5Àn X (X ¼ Cl À , Br À , I À ; 0 # n # 6) is considered one of the important factors enhancing stability. [43][44][45] Although experimental improvements and atomistic calculations for thermodynamic stability by O substitution have been reported depending on the substitution ratio of O to S, the mechanism underlying O introduction into sulde-based Li 6 PS 5 X (X ¼ Cl À , Br À , I À ) SEs remains unclear. For practical application of these methods to argyrodite SEs, the different chemical environments on the sites of S (e.g., 4d and 16e) in argyrodite SEs where O is substituted need to be systemically examined because the stabilities related to O introduction might differ depending on the electrochemical environment of the sites under atmospheric conditions from the surface region.…”