Protective sulfide coatings on silver electrodes for electrochemical devices
US20250244134A1
Abstract
Disclosed herein is a porous substrate having silver and optionally silver oxide and a silver sulfide coating. Also disclosed herein is a battery having a cathode, an anode, and a separator between the cathode and the anode. The cathode includes a substrate having silver and optionally silver oxide and a silver sulfide coating. Also disclosed herein is a method of submerging a substrate having silver and optionally silver oxide in a solution of elemental sulfur in dimethyl sulfoxide to form silver sulfide on the surface of the substrate.
Description (excerpt)
REFERENCE TO RELATED APPLICATIONS This application is a continuation application of U.S. application Ser. No. 18/752,152, filed on Jun. 27, 2024, which claims the benefit of U.S. Provisional Application No. 63/511,402, filed on Jun. 30, 2023. The provisional application and all other publications and patent documents referred to throughout this nonprovisional application are incorporated herein by reference. TECHNICAL FIELD The present disclosure is generally related to silver cathodes. DESCRIPTION OF THE RELATED ART Silver-oxide batteries are renowned for high power and high energy density, but cyclability and shelf life are poor due to the instability of the silver-oxide cathode (Parker et al., Journal of DoD Research & Engineering 2022, 5, AD1185991). Spontaneous and electrochemical degradation of the silver oxide generates mobile silver species that react with the battery separator. In traditional silver-oxide batteries (e.g., silver-zinc), the separator comprises three distinct layers serving different functions: (i.) a nylon separator contacting the silver oxide cathode for electrolyte retention, (ii.) a middle layer of cellophane to react with any labile silver species, and (iii.) a polypropylene separator contacting the zinc to mitigate dendrite growth. This separator system functions adequately for a primary battery, but the ultimate degradation of the cellophane layer limits the long-term cycle life of rechargeable silver-oxide batteries. Additionally, the supply chain for battery-grade cellophane is becoming tenuous, endangering the long-term prospects to manufacture high-performance silver-oxide batteries that power important DoD applications (Beard, Linden's Handbook of Batteries, McGraw-Hill Education, 2019; Fleischer et al., Zinc-Silver Oxide Batteries, John Wiley and Sons, Inc., 1971). These challenges necessitate new strategies for stabilizing the silver oxide within the cathode itself. SUMMARY OF THE INVENTION Disclosed herein is an article comprising a porous substrate comprising silver and optionally silver oxide and a silver sulfide coating on at least a portion of the porous substrate. Also disclosed herein is a battery comprising a cathode, an anode, and a separator between the cathode and the anode. The cathode comprises a substrate comprising silver and optionally silver oxide and a silver sulfide coating on at least a portion of the substrate. Also disclosed herein is a method comprising providing a solution of elemental sulfur in dimethyl sulfoxide and submerging a substrate comprising silver and optionally silver oxide in the solution to form silver sulfide on the surface of the substrate. BRIEF DESCRIPTION OF DRAWINGS A more complete appreciation will be readily obtained by reference to the following Description of the Example Embodiments and the accompanying drawings. FIG. 1 shows a photograph of silver-foil electrodes before (Ag, Ag 2 O) and after sulfidization (S@Ag, S@Ag 2 O). Electrodes finished cycling in the reduced state and active area was limited to the grey circle in the center of each substrate. FIGS. 2 A-B show cyclic voltammetric response of unmodified and sulfidized silver foil electrodes over the potential window for Ag 0/+ redox ( FIG. 2 A ) and a restricted potential window that encompasses the region where silver dissolution occurs ( FIG. 2 B ). A three-electrode beaker cell equipped with platinum-wire counter electrode and Hg/HgO reference electrode was used. FIGS. 3 A-B show X-ray photoelectron spectroscopy (XPS) of uncycled silver-foil electrodes in the Ag 3d 5/2 region ( FIG. 3 A ) and the S 2p region ( FIG. 3 B ). FIGS. 4 A-B show post-cycling X-ray photoelectron spectroscopy (XPS) of silver foil electrodes in the Ag 3d 5/2 region ( FIG. 4 A ) and the S 2p region ( FIG. 4 B ). FIG. 5 shows scanning electron micrographs of silver foil electrodes with (S@Ag, S@Ag 2 O) and without sulfidization (Ag, Ag 2</sub
Filing details
- Inventors
- Ryan H. DeBlock
- Assignee
- The Government Of The United States Of America, As Represented By The Secretary …
- Filed
- Mar 14, 2025
- Granted
- Application pending
Bibliographic data and excerpted text sourced from Google Patents (public record) as part of IP TechMatch's current-filings monitor. This filing is not part of the 2019 historical archive. For the authoritative full text, drawings, and legal status, see the source links above or consult USPTO records directly.