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US-20260128369-A1 - SOLID ELECTROLYTE, METHOD FOR MANUFACTURING THE SAME, AND BATTERY

US20260128369A1US 20260128369 A1US20260128369 A1US 20260128369A1US-20260128369-A1

Abstract

A solid electrolyte, a method for manufacturing the solid electrolyte, and a battery are disclosed. The solid electrolyte includes a polymer, a silver salt, and an alkali metal salt. When the solid electrolyte provided in the present disclosure is matched with a metal such as lithium metal, a gradient SEI layer rich in inorganic components can be in-situ generated during electrochemical cycling. The gradient SEI layer includes an outer layer rich in silver-containing inorganic components and an inner layer rich in lithium-containing inorganic components. Thus, the battery possesses high ionic conductivity and stability against the lithium metal anode, and the in-situ constructed SEI layer can uniformize lithium ion deposition, inhibit lithium dendrite growth, realize stable cycling under high current, and exhibit excellent low-temperature electrochemical performance.

Inventors

  • YAN-BING HE
  • FEI-YU KANG
  • Jin-Shuo Mi
  • Ting-Zheng Hou
  • Ming Liu
  • Ke Yang
  • Jia-Bin Ma
  • Li-Kun Chen
  • Jie Biao
  • Cui-Cui Wang

Assignees

  • Tsinghua Shenzhen International Graduate School

Dates

Publication Date
20260507
Application Date
20251231
Priority Date
20230922

Claims (20)

  1. 1 . A solid electrolyte, comprising: a polymer, a silver salt, and an alkali metal salt.
  2. 2 . The solid electrolyte of claim 1 , wherein the silver salt comprises at least one of AgNO 3 , AgTFSI, and AgClO 3 .
  3. 3 . The solid electrolyte of claim 1 , wherein based on a mass of the solid electrolyte, a content of the silver salt is 1.5 wt. %˜10 wt. %.
  4. 4 . The solid electrolyte of claim 1 , wherein the alkali metal salt is a sulfur-containing alkali metal salt.
  5. 5 . The solid electrolyte of claim 4 , wherein the sulfur-containing alkali metal salt comprises at least one of lithium bis(fluorosulfonyl)imide and lithium bis(trifluoromethanesulfonyl)imide.
  6. 6 . The solid electrolyte of claim 1 , further comprising a plurality of ceramic particles, wherein the plurality of ceramic particles comprises at least one of Li 7 La 3 Zr 2 O 12 ceramic particles, Li 1.3 Al 0.3 Ti 1.7 (PO 4 ) 3 ceramic particles, SiO 2 ceramic particles, and Al 2 O 3 ceramic particles.
  7. 7 . The solid electrolyte of claim 1 , wherein the polymer comprises at least one of polyethylene oxide, polyvinylidene fluoride, and polyvinylidene fluoride-hexafluoropropylene.
  8. 8 . A battery, comprising: a metal electrode; and a solid electrolyte in physical contact with the metal electrode, wherein the solid electrolyte comprises a polymer, a silver salt, and an alkali metal salt, and a solid electrolyte interphase (SEI) layer formed on a surface of the solid electrolyte contacting the metal electrode.
  9. 9 . The battery of claim 8 , wherein the silver salt comprises at least one of AgNO 3 , AgTFSI, and AgClO 3 .
  10. 10 . The battery of claim 8 , wherein based on a mass of the solid electrolyte, a content of the silver salt is 1.5 wt. %˜10 wt. %.
  11. 11 . The battery of claim 8 , wherein the alkali metal salt is a sulfur-containing alkali metal salt, the sulfur-containing alkali metal salt comprises at least one of lithium bis(fluorosulfonyl)imide and lithium bis(trifluoromethanesulfonyl)imide.
  12. 12 . The battery of claim 8 , wherein the solid electrolyte further comprises a plurality of ceramic particles, the plurality of ceramic particles comprises at least one of Li 7 La 3 Zr 2 O 12 ceramic particles, Li 1.3 Al 0.3 Ti 1.7 (PO 4 ) 3 ceramic particles, SiO 2 ceramic particles, and Al 2 O 3 ceramic particles.
  13. 13 . The battery of claim 8 , wherein the polymer comprises at least one of polyethylene oxide, polyvinylidene fluoride, and polyvinylidene fluoride-hexafluoropropylene.
  14. 14 . The battery of claim 8 , wherein the SEI layer comprises alkali metal-containing inorganic salts and silver-containing inorganic salts.
  15. 15 . The battery of claim 14 , wherein a side of the SEI layer adjacent to the alkali metal is an inner layer, and a side away from the alkali metal is an outer layer; in the SEI layer, a content of the alkali metal-containing inorganic salts decreases from the inner layer to the outer layer, while a content of the silver-containing inorganic salts increases from the inner layer to the outer layer.
  16. 16 . The battery of claim 14 , wherein the alkali metal is metallic lithium, the alkali metal-containing inorganic salts comprise at least one of LiF, Li 3 N, and Li 2 S; the silver-containing inorganic salts comprise at least one of Ag 2 S and AgF.
  17. 17 . A method for manufacturing a solid electrolyte, comprising: mixing a polymer, a silver salt, and a lithium salt to obtain a mixed solution; and drying the mixed solution to obtain the solid electrolyte.
  18. 18 . The method of claim 17 , wherein the silver salt comprises at least one of AgNO 3 , AgTFSI, and AgClO 3 .
  19. 19 . The method of claim 18 , wherein the lithium salt comprises at least one of lithium bis(fluorosulfonyl)imide and lithium bis(trifluoromethanesulfonyl)imide.
  20. 20 . The method of claim 17 , wherein the mixed solution further comprises a plurality of ceramic particles, the plurality of ceramic particles comprises at least one of Li 7 La 3 Zr 2 O 12 ceramic particles, Li 1.3 Al 0.3 Ti 1.7 (PO 4 ) 3 ceramic particles, SiO 2 ceramic particles, and Al 2 O 3 ceramic particles.

Description

CROSS-REFERENCE TO RELATED APPLICATION(S) The present application claims the benefit and priority to Chinese Patent Application Serial No. 202311086352.9, filed on Sep. 22, 2023, in China National Intellectual Property Administration, and the content of which is hereby fully incorporated by reference into the present application. FIELD The subject matter herein generally relates to a solid electrolyte, a method for manufacturing the same, and a battery. BACKGROUND Lithium-ion batteries (LIBs) exhibit numerous advantages, including low self-discharge rate, absence of memory effect, high energy density, and long cycle life, thereby enabling their widespread adoption in consumer electronics, energy storage, new energy, and other fields. Currently, lithium metal is recognized as a highly promising anode material for high-energy lithium batteries. However, liquid lithium-ion batteries suffer from severe issues such as intense interfacial reactions and inadequate safety performance. Theoretically, solid lithium-ion batteries (SSLIBs) featuring high energy density and superior safety represent the most promising alternatives to liquid lithium-ion batteries. Nevertheless, during electrochemical cycling of a lithium metal battery assembled with a solid polymer electrolyte (SPE), a solid electrolyte interface (SEI) formed on a side close to the lithium metal undergoes repeated fracture and reconstruction, accompanied by severe lithium dendrite growth. In particular, short circuits are prone to occur under high current densities, posing a significant barrier to achieving high-flux operation. BRIEF DESCRIPTION OF THE DRAWINGS Implementations of the present disclosure will now be described, by way of example only, with reference to the attached figures. FIG. 1 is a flowchart of a method for manufacturing a solid electrolyte according to an embodiment of the present disclosure. FIG. 2 is a diagrammatic view of a battery according to an embodiment of the present disclosure. FIG. 3A is a cross-sectional scanning electron microscopy (SEM) image of a PVAL composite solid electrolyte prepared in Preparation Example 1 of the present disclosure. FIG. 3B is a cross-sectional SEM image of a PVL composite solid electrolyte prepared in Comparative Preparation Example 1 of the present disclosure. FIG. 3C is a morphological structure of a gradient SEI layer rich in inorganic components formed in a Li—Cu half-cell based on the PVAL composite solid electrolyte membrane (named as PVAL/Li—Cu half-cell) in Example 1 under a cryogenic transmission electron microscope. FIGS. 4A to 4F are enlarged views of Parts A to F in FIG. 3C, respectively. FIG. 5 is a morphological structure of the gradient SEI layer shown in FIG. 3C with silver-containing inorganic salts and lithium-containing inorganic salts labeled. FIG. 6 shows coulombic efficiency test curves of the PVAL/Li—Cu half-cell in Example 1 and a Li—Cu half-cell based on the PVL composite solid electrolyte membrane (named as PVL/Li—Cu half-cell) in Comparative Example 1. FIG. 7 shows nucleation potential test curves of the PVAL/Li—Cu half-cell in Example 1 and the PVL/Li—Cu half-cell in Comparative Example 1. FIG. 8 shows cross-sectional SEM images of nucleation of the PVL/Li—Cu half-cell in Comparative Example 1 and nucleation of the PVAL/Li—Cu half-cell in Example 1, respectively. FIG. 9 shows surface SEM images of nucleation of the PVL/Li—Cu half-cell in Comparative Example 1 and nucleation of the PVAL/Li—Cu half-cell in Example 1, respectively. FIG. 10 shows a surface SEM image of lithium metal deposition after depositing 1 mAh at 0.5 mA/cm2for a Li—Li symmetric cell based on the PVL composite solid electrolyte membrane (named as PVL/Li—Li symmetric cell) in Comparative Example 1, and surface SEM images of lithium metal deposition after depositing 1 mAh, 10 mAh, and 20 mAh at 0.5 mA/cm2 respectively for a Li—Li symmetric cell based on the PVAL composite solid electrolyte membrane (named as PVAL/Li—Li symmetric cell) in Example 1. FIG. 11 shows cross-sectional SEM images of lithium metal deposition after depositing 5 mAh at 0.5 mA/cm2 for the PVL/Li—Li symmetric cell in Comparative Example 1 and the PVAL/Li—Li symmetric cell in Example 1, respectively. FIG. 12 shows exchange current density test curves of the PVAL/Li—Li symmetric cell in Example 1 and the PVL/Li—Li symmetric cell in Comparative Example 1. FIG. 13 shows critical current density (CCD) test curves of the PVAL/Li—Li symmetric cell in Example 1 and the PVL/Li—Li symmetric cell in Comparative Example 1. FIG. 14 shows long-cycle test curves of the PVAL/Li—Li symmetric cell in Example 1 and the PVL/Li—Li symmetric cell in Comparative Example 1 under 10 mA/cm2and 10 mAh/cm2, respectively. FIG. 15 shows impedance test curves of the PVAL/Li—Li symmetric cell in Example 1 before and after cycling, respectively. FIG. 16 shows XPS test curves of S2p on the lithium metal surface after cycling for the PVAL/Li—Li symmetric cell in Examp