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Title: Nanoscale Solid State Batteries Enabled by Thermal Atomic Layer Deposition of a Lithium Polyphosphazene Solid State Electrolyte

Several active areas of research in novel energy storage technologies, including three-dimensional solid state batteries and passivation coatings for reactive battery electrode components, require conformal solid state electrolytes. We describe an atomic layer deposition (ALD) process for a member of the lithium phosphorus oxynitride (LiPON) family, which is employed as a thin film lithium-conducting solid electrolyte. The reaction between lithium tert-butoxide (LiO tBu) and diethyl phosphoramidate (DEPA) produces conformal, ionically conductive thin films with a stoichiometry close to Li 2PO 2N between 250 and 300°C. The P/N ratio of the films is always 1, indicative of a particular polymorph of LiPON which closely resembles a polyphosphazene. Films grown at 300°C have an ionic conductivity of (6.51 ± 0.36)×10 -7 S/cm at 35°C, and are functionally electrochemically stable in the window from 0 to 5.3V vs. Li/Li +. We demonstrate the viability of the ALD-grown electrolyte by integrating it into full solid state batteries, including thin film devices using LiCoO 2 as the cathode and Si as the anode operating at up to 1 mA/cm 2. The high quality of the ALD growth process allows pinhole-free deposition even on rough crystalline surfaces, and we demonstrate the fabrication and operation of thinmore » film batteries with the thinnest (<40nm) solid state electrolytes yet reported. Finally, we show an additional application of the moderate-temperature ALD process by demonstrating a flexible solid state battery fabricated on a polymer substrate.« less
ORCiD logo [1] ;  [1] ;  [2] ;  [2] ;  [1] ;  [3] ;  [4] ; ORCiD logo [2] ;  [1] ;  [1]
  1. Univ. of Maryland, College Park, MD (United States). Dept. of Materials Science and Engineering
  2. Sandia National Lab. (SNL-CA), Livermore, CA (United States)
  3. Johns Hopkins Univ., Laurel, MD (United States). Applied Physics Lab., Dept. of Research and Exploratory Development
  4. American Society for Engineering Education, Washington, DC (United States)
Publication Date:
Report Number(s):
Journal ID: ISSN 0897-4756; 651195
Grant/Contract Number:
AC04-94AL85000; SC0001160
Accepted Manuscript
Journal Name:
Chemistry of Materials
Additional Journal Information:
Journal Volume: 29; Journal Issue: 8; Journal ID: ISSN 0897-4756
American Chemical Society (ACS)
Research Org:
Sandia National Lab. (SNL-CA), Livermore, CA (United States)
Sponsoring Org:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22); USDOE National Nuclear Security Administration (NNSA)
Country of Publication:
United States
25 ENERGY STORAGE; Atomic layer deposition; solid state battery; solid state electrolyte; LiPON; thin film; energy storage; flexible
OSTI Identifier: