Cl-Doped Li₁₀SnP₂S₁₂ with Enhanced Ionic Conductivity and Lower Li-Ion Migration Barrier

Abstract

All-solid-state lithium batteries based on sulfide solid electrolytes have attracted much attention because of their high ionic conductivity. Li10SnP2S12 (LSPS) has the same structure as Li10GeP2S12, and there is little difference in ionic conductivity between them, but the preparation cost of LSPS is lower. Here, Cl doping is used to improve the electrochemical stability of the LSPS to the anode and the Li-ion transport performance. Among them, Li9.9SnP2S11.9Cl0.1 had a high ion conductivity of 2.62 mS cm–1 after cold pressure. On the crystal structure, X-ray diffraction Rietveld refinement indicated that the Cl-substituted portion S is successfully incorporated into the lattice of the LSPS, increasing Li-ion vacancies and reducing the distance between adjacent Li-ion distributed along the c-axis, these are conducive to Li-ion transmission. The temperature-dependent AC impedance experiment and density functional theory calculation show that doping with Cl makes Li9.9SnP2S11.9Cl0.1 have a lower activation energy. The assembled lithium symmetric batteries show that the doping of Cl promotes the stability of the interface between LSPS and the lithium metal anode. The charge–discharge tests of all-solid-state batteries using Li9.9SnP2S11.9Cl0.1 as electrolyte have confirmed that Cl doping can improve the electrochemical performance of LSPS, which have a higher specific capacity and cycle life.

An ultrahigh energy density Mg–air battery with organic acid–solid anolyte biphasic electrolytes

“…S6a and b †), thus the Mg in the matrix was able to react and the formed Mg 2+ ions could be easily conducted instead of accumulating on the AZ61 Mg alloy anode surface. [38][39][40] So, the inhibition of surface passivation greatly reduced the anode polarization. Satisfactorily, the prepared SA/ NaCl solid electrolyte possesses good compatibility with the AZ61 Mg alloy anode 41,42 with a low self-corrosion rate 6.59 × 10 −4 mg cm −2 h, which is only 1/40 of the one in 10 wt% NaCl aqueous solution electrolyte (Fig.…”

Solid‐State Electrolytes and Electrode/Electrolyte Interfaces in Rechargeable Batteries

“…reported a solid lithium superionic conductor Li 11 AlP 2 S 12 with a 3D framework structure showing an excellent wide electrochemical voltage window of higher than 5.0 V (vs. Li + /Li) and ionic conductivity of 0.802 mS cm −1 at RT. The reported Li 10 SnP 2 S 12 is isostructural to Li 10 GeP 2 S 12 but the Li + ions are slightly disordered, resulting in a lower grain boundary resistance and higher ionic conductivity of 1.58 mS cm −1 than Li 11 AlP 2 S 12 at RT [127] . The substitution of Si and S sites with Sn and Cl can also greatly reduce grain boundary resistance and improve the ionic conductivity of electrolytes.…”

“…The reported Li 10 SnP 2 S 12 is isostructural to Li 10 GeP 2 S 12 but the Li + ions are slightly disordered, resulting in a lower grain boundary resistance and higher ionic conductivity of 1.58 mS cm À 1 than Li 11 AlP 2 S 12 at RT. [127] The substitution of Si and S sites with Sn and Cl can also greatly reduce grain boundary resistance and improve the ionic conductivity of electrolytes. The Li 10 Sn 0.7 Si 0.3 P 2 S 12 [128] and Li 9.9 SnP 2 S 11.9 Cl 0.1 [127] electrolytes achieved the ionic conductivities of 8 mS cm À 1 and 2.62 mS cm À 1 at RT.…”

“…[127] The substitution of Si and S sites with Sn and Cl can also greatly reduce grain boundary resistance and improve the ionic conductivity of electrolytes. The Li 10 Sn 0.7 Si 0.3 P 2 S 12 [128] and Li 9.9 SnP 2 S 11.9 Cl 0.1 [127] electrolytes achieved the ionic conductivities of 8 mS cm À 1 and 2.62 mS cm À 1 at RT. In addition, the Li 9.54 Si 1.74 P 1.44 S 11.7 Cl 0.3 exhibited the highest ionic conductivity of 25 mS cm À 1 and a wider electrochemical window at RT in Li 11-x M 2-x P 1 + x S 12 family.…”

Recent Developments in the Field of Sulfide Ceramic Solid‐State Electrolytes

“…Regarding tin substitution for germanium, σ RT of 7 [ 40 ] and 4 mS cm −1 [ 41 ] were reported for Li 10 SnP 2 S 12 (LSnPS) SSE, σ RT of 2.1 mS cm −1 was reported for tin‐based glass‐ceramic thio‐LISICON (2.5·Li 3 PS 4 −0.5·Li 4 SnS 4 ), [ 42 ] and σ RT of 2.62 mS cm −1 was reported for the chlorine‐doped Li 9.9 SnP 2 S 11.9 Cl 0.1 (LSnPS–Cl). [ 43 ] Apropos of silicon substitution for germanium, σ RT of 4.28 mS cm −1 was reported for Li 10.35 Si 1.35 P 1.65 S 12 (LSiPS), σ RT of 6.91 mS cm −1 was reported for 1% Co 4+ ‐doped Li 10.35 Si 1.35 P 1.65 S 12 SSE, [ 44 ] Li 10 Si 0.3 Sn 0.7 P 2 S 12 exhibits σ RT ≈ 8 mS cm −1 , [ 45 ] and the outstandingly high σ RT of 25 mS cm −1 was reported for Li 9.54 Si 1.74 P 1.44 S 11.7 Cl 0.3 (LSiPS–Cl). [ 46 ] Partially aluminum‐substituted Li 10.3 Al 0.3 Sn 0.7 P 2 S 12 demonstrated σ RT = 2 mS cm −1 , [ 45 ] while fully aluminum substituted Li 11 AlP 2 S 12 had the smaller σ RT = 0.8 mS cm −1 .…”