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JP-7857233-B2 - Electrolytes for target ion transport

JP7857233B2JP 7857233 B2JP7857233 B2JP 7857233B2JP-7857233-B2

Inventors

  • ジェニー プリングル
  • カロリーナ マッツゼック
  • ティム ニュービギン
  • ファゼ マクローギ アザド

Assignees

  • ディーキン ユニバーシティ
  • モナシュ ユニバーシティ

Dates

Publication Date
20260512
Application Date
20210513
Priority Date
20200513

Claims (16)

  1. Select from the following: Zwitterionic viscous crystal (ZIPC) compounds.
  2. Use of the compound according to claim 1 as a solid solvent.
  3. Use of the compound according to claim 1 as an electrolyte matrix.
  4. Use of the compound according to claim 1 as a solid-state electrolyte matrix.
  5. Use of the compound according to claim 1 as a conductivity-enhancing additive in an electrolyte.
  6. A zwitterionic viscous crystal composition in liquid or solid form, comprising the zwitterionic viscous crystal (ZIPC) compound described in claim 1 , and an ionic salt, acid, base, Li or Na functionalized polymer, or a combination thereof.
  7. The zwitterionic viscous crystalline composition according to claim 6 , wherein the ZIPC is present in a concentration of at least 5 mol%.
  8. The zwitterionic viscous crystalline composition according to claim 6 , wherein the ionic salt is one or more of alkali metal salts, alkaline earth metal salts, or transition metal salts.
  9. The zwitterionic viscous crystalline composition according to claim 6 , wherein the ionic salt is either a lithium salt or a sodium salt, or both.
  10. The zwitterionic flexible crystalline composition according to claim 6, wherein the ionic salt is an alkali metal salt selected from one or more of LiBF₄, LiFSI, LiNTf₂ , lithium bis(trifluoromethanesulfonyl)imide (Li[TFSI]), lithium (bis(fluorosulfonyl)imide (Li[FSI]), lithium triflate (Li[OTf]), lithium perchlorate (LiClO₄), lithium dicyanamide (LiDCA), lithium cyanate (LiOCN), lithium bis[(pentafluoroethyl)sulfonyl]imide, lithium 2,2,2-trifluoromethylsulfonyl-N-cyanoamide (TFSAM), lithium 2,2,2-trifluoro-N-(trifluoromethylsulfonyl)acetamide (TSAC), lithium nonafluorobutanesulfonate (NF), lithium carborane, and lithium difluoro ( oxolato)borate.
  11. The zwitterionic viscous crystalline composition according to claim 6 , wherein the acid is trifluic acid and the base is imidazole.
  12. A solid-state electrolyte comprising the zwitterionic viscous crystal (ZIPC) compound described in claim 1 .
  13. A solid-state electrolyte comprising the solid-state composition described in claim 6 .
  14. An energy storage device comprising an electrolyte containing the zwitterionic viscous crystal (ZIPC) compound described in claim 1 .
  15. The energy storage device according to claim 14 , wherein the electrolyte further comprises an ionic salt, an acid, a base, a Li or Na functionalized polymer, or a combination thereof.
  16. The energy storage device according to claim 15 , wherein the energy storage device is a Na battery or a Li battery.

Description

This invention relates to a flexible crystalline compound having excellent target ion conduction capabilities, and can be used, for example, as an electrolyte in various applications where high-speed target ion conduction is desired. Viscous crystals are solids that have a long-range ordered crystalline structure along with short-range disorder resulting from rotation or disorientation of individual molecules/ions within an ordered lattice. Short-range molecular rearrangement gives rise to the ability to deform under load (i.e., plasticity) and enhances the diffusivity of a second kind within the viscous crystal lattice. Viscous crystalline electrolytes can be classified as fast ion conductors in which primary/target ions (e.g., Li + for lithium batteries, or I- / I3- for dye-sensitized solar cells) move rapidly against a relatively static matrix background. In recent years, the applicability of organic ionic flexible crystals (OIPCs) as novel solid-state ion conductors in lithium batteries, dye-sensitized solar cells, fuel cells, and sodium batteries has been demonstrated. This is achieved by doping OIPCs with appropriate cations, for example, by adding Li salts for their application in lithium batteries, or acids or bases for fuel cells. Furthermore, aprotic OIPCs offer good thermal and electrochemical stability and, due to their negligible volatility, significantly improve safety compared to current molecular solvent-based electrolytes. OIPCs can be structurally disordered salts, exhibiting flexible and plastic mechanical properties and significant ionic conductivity. The structural disorder within OIPCs promotes fast target ion conduction when OIPCs are used as a matrix and a second component (e.g., acid/base for fuel cells or Li or Na salt for Li/Na batteries) is introduced into the OIPC matrix, enabling their use as solid electrolytes in electrochemical devices. However, their inherent structures (i.e., separated cations and anions) are thought to allow undesirable movement of matrix OIPC ions. In an ideal electrolyte material, only target ions (e.g., Li, Na, H) would move. However, target ion transport through OIPC is still insufficient and ultimately limits the power output achievable by the instrument. In fact, the transport rate (the proportion of charge possessed by the active species), for example, t Li+ for OIPC, is generally less than 0.2. This is because there are other charged transport species, including the cations and anions of OIPC as well as the counterions of lithium salts. For an ideal transport rate (t Li+ = 1), only Li ions would need to move through the electrolyte at a very high speed. [Overview of the prefecture] [Problems the invention aims to solve] While zwitterionic liquids and even zwitterionic liquid crystals are known, in rare cases, zwitterionic liquid crystals in combination with LiNTf2 and propylene carbonate can be used as a liquid electrolyte, but leakage from the apparatus and the vapor pressure and flammability of this combination pose problems. In the field of electrochemistry, organic ionic zwitterions utilize sulfonate structures because they can be synthesized relatively easily in one step via combinations of sulfones and methylpyrrolidines. However, these sulfonic acid zwitterions are crystalline solids that do not show evidence of plasticity and lack the flexible mechanical properties required for battery cells, making them unsuitable as standalone electrolyte matrix materials . Ohno et al. (Phys. Chem. Chem. Phys. 2018, 20, 10978) describe an alkyl-substituted imidazolium zwitterion with a solid-solid transition at 165°C, lower than its own Tm. However, in addition to the low entropy of the molten material, there is no evidence that this zwitterion exhibits plastic behavior, and viscous zwitterions need to show evidence of disorder, preferably determined by NMR studies . [Means for solving the problem] This disclosure provides an organic zwitterionic compound that exhibits plasticity evidenced by molecular disorder in the solid state, as defined in claim 1, and can be used as a solid-state electrolyte. In the first reference embodiment, the present invention relates to a zwitterionic viscous crystal (ZIPC) compound in the form of a nonpolymer molecule, At least one positively charged functional group having at least one positive charge, At least one negatively charged functional group having at least one negative charge, Includes, The positively charged functional group and the negatively charged functional group are covalently linked to each other within the molecule, the net charge of the zwitterionic compound is zero, the compound exhibits molecular disorder in the solid state, and the compound is as follows: Thermal phase behavior including one or more solid-to-solid phase transitions before melting, In the solid state, an NMR linewidth of 1 or more with a frequency of 20 kHz or less, The present invention provides a zwitterionic viscous crystal (ZIPC) co