Design, Synthesis, and Characterization of Polymer Precursors to Li_xPON and Li_xSiPON Glasses: Materials That Enable All-Solid-State Batteries (ASBs)

Abstract

LiPON-like glasses that form lithium dendrite impenetrable interfaces between lithium battery components are enabling materials that may replace liquid electrolytes permitting production of all-solid-state batteries (ASBs). Unfortunately, to date, such materials are introduced only via gas-phase deposition. Here, we demonstrate the design and synthesis of easily scaled, low-temperature, low-cost, solution-processable inorganic polymers containing LiPON/LiSiPON elements. OPCl3 and hexachlorophosphazene [Cl2PN]3 provide starting points for elaboration using MNH2 (M = Li/Na) or (Me3Si)­NH followed by reaction with controlled amounts of LiNH2 to produce oligomers/polymers with molecular weights (MWs) ≈1–2 kDa characterized by multinuclear NMR, gel permeation chromatography (GPC), thermogravimetric analysis (TGA), Fourier-transform infrared (FTIR), X-ray powder diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and matrix-assisted laser desorption/ionization (MALDI)-time-of-flight (ToF) offering stabilities to 150–200 °C and ceramic yields (800 °C) of 50–60%. 7Li NMR suggests that precursor-bound Li+ dissociates easily, beneficial for electrochemical applications. XPS shows higher N/P ratios (1–3) than via gas-phase methods (<1) correlating N/P ratios, 7Li shifts, and Li+ conductivities. Li2SiPHN offers the highest ambient conductivity of 3 × 10–1 mS cm–1 at 400 °C/2 h/N2.

Reactions of metal chlorides with hexamethyldisilazane: Novel precursors to aluminum nitride and beyond

“…Similar MALDI analyses were done previously on Li x PONlike and Li x SiON precursors for lithium-ion battery applications. 37,38,48 Figure 1A,B shows negative-and positive-ion MALDIs of the Al-HMDS precursor, respectively. Both exhibit oligomeric peaks in the range of 300-500 m/z.…”

“…However, commodity scale production is challenging given the required specialized and expensive apparatus and low production rates (generally < 100 nm/min). [37][38][39] Here, we report a simple reaction of AlCl 3 with hexamethyldisilazane [HMDS, (Me 3 Si) 2 NH] in tetrahydrofuran (THF) or acetonitrile (ACN) at 60 • C/N 2 to produce an AlN precursor, Al(NHSiMe 3 ) 3 (denoted as Al-HMDS for convenience), as suggested by reaction (3). The byproduct Me 3 SiCl (boiling point = 57 • C) can be removed easily along with THF/ACN and excess HMDS by drying at 80 • C/1 h/vacuum (vac).…”

Electrochemical Performance of LixSiON Polymer Electrolytes Derived from an Agriculture Waste Product, Rice Hull Ash

“…17,20,21,23 Recently, we demonstrated that the introduction of Si into Li polymer electrolyte (Li x SiPON) by shortening the distance between Li + binding sites. 21,24 With this background, here we investigate the effect of N introduction into amorphous Li 4 SiO 4 -like polymer analogs. Exploration of Li + -containing oxynitrides as electrolytes has been limited to thin-film batteries because of their low ionic conductivities (10 −6 S cm −1 ) at ambient temperature.…”

“…Thus, controlling the nitrogen content is key to achieving a higher ionic conductivity. , Both computational and experimental studies have demonstrated that amorphous rather than crystalline LiPON is a better Li conductor attributed to increases in diffusion/conduction due to reduction of overall electrostatic interactions and higher disorder within the material. ,,, Recently, we demonstrated that the introduction of Si into Li x PON polymer electrolytes enhances ionic conductivity and lowers the activation energy of the polymer electrolyte (Li x SiPON) by shortening the distance between Li + binding sites. , With this background, here we investigate the effect of N introduction into amorphous Li 4 SiO 4 -like polymer analogs.…”

LiAlO2/LiAl5O8 Membranes Derived from Flame-Synthesized Nanopowders as a Potential Electrolyte and Coating Material for All-Solid-State Batteries

“…The fabrication of these extremely thin films requires gas-phase deposition techniques. However, the exploration of Li + conductive thin-film electrolytes by gas-phase deposition techniques, such as ALD, ion beam-assisted deposition, and pulse laser deposition, is still at an early stage as such methods are energy and equipment intensive, require high-cost process steps, and offer low deposition rates . Thus, there remains a considerable need to develop alternate methods of processing membranes with optimal conductivity as potential candidates for next generation ASSBs.…”