Oxide-Based Composite Electrolytes Using Na₃Zr₂Si₂PO₁₂/Na₃PS₄ Interfacial Ion Transfer

Abstract

All-solid-state sodium batteries using NaZrSiPO (NASICON) solid electrolytes are promising candidates for safe and low-cost advanced rechargeable battery systems. Although NASICON electrolytes have intrinsically high sodium-ion conductivities, their high sintering temperatures interfere with the immediate development of high-performance batteries. In this work, sintering-free NASICON-based composites with NaPS (NPS) glass ceramics were prepared to combine the high grain-bulk conductivity of NASICON and the interfacial formation ability of NPS. Before the composite preparation, the NASICON/NPS interfacial resistance was investigated by modeling the interface between the NASICON sintered ceramic and the NPS glass thin film. The interfacial ion-transfer resistance was very small above room temperature; the area-specific resistances at 25 and 100 °C were 15.8 and 0.40 Ω cm, respectively. On the basis of this smooth ion transfer, NASICON-rich (70-90 wt %) NASICON-NPS composite powders were prepared by ball-milling fine powders of each component. The composite powders were well-densified by pressing at room temperature. Scanning electron microscopy observation showed highly dispersed sub-micrometer NASICON grains in a dense NPS matrix to form closed interfaces between the oxide and sulfide solid electrolytes. The composite green (unfired) compacts with 70 and 80 wt % NASICON exhibited high total conductivities at 100 °C of 1.1 × 10 and 6.8 × 10 S cm, respectively. An all-solid-state NaSn/TiS cell was constructed using the 70 wt % NASICON composite electrolyte by the uniaxial pressing of the powder materials, and its discharge properties were evaluated at 100 °C. The cell showed the reversible capacities of about 120 mAh g under the current density of 640 μA cm. The prepared oxide-based composite electrolytes were thus successfully applied in all-solid-state sodium rechargeable batteries without sintering.

From Liquid- to Solid-State Batteries: Ion Transfer Kinetics of Heteroionic Interfaces

“…To the best of our knowledge, the only study directly determining the interfacial resistance between two solid alkali-ion conductors was conducted for the Na 3 Zr 2 Si 2 PO 12 ∕Na 3 PS 4 interface [88]. An interfacial resistance of 16 Ω cm 2 at 25 • C and activation energy of 0.47 eV were reported, confirming the assumptions drawn above from analyzing the internal resistance of SSBs.…”

“…An interfacial resistance of 16 Ω cm 2 at 25 • C and activation energy of 0.47 eV were reported, confirming the assumptions drawn above from analyzing the internal resistance of SSBs. The decreased values compared to the Na + transfer at the SE/ PE interface [41] were explained with a smaller difference in chemical potential of Na + in NASICON and in Na 3 PS 4 compared to that of Na + in NASICON and the PE [88].…”

Effective Approaches of Improving the Performance of Chalcogenide Solid Electrolytes for All-Solid-State Sodium-Ion Batteries

“…Ion doping and substitution are common methods of material modification (Bo et al, 2016;Kato et al, 2016;Richards et al, 2016;Krauskopf et al, 2017;Rao et al, 2017;Wang et al, 2017;Mahmoud et al, 2019;Wan et al, 2020;Zhang et al, 2020). Cation ion doping into the P site or halogen doping into the S site can introduce vacancies to improve the ionic conductivity of the CSEs (Zhang et al, 2015;Bo et al, 2016;Wang et al, 2016;Krauskopf et al, 2017Krauskopf et al, , 2018aYu et al, 2017).…”

“…Moreover, inorganic solid electrolytes include Na-β-Al 2 O 3 , NASICON (Na super ionic conductor), borohydride, and chalcogenide. At present, chalcogenide solid electrolytes (CSEs) are mainly divided into four categories: Na 3 MS 4 (M = P, Sb) series (Tanibata et al, 2017;Krauskopf et al, 2018a;Noi et al, 2018;Takeuchi et al, 2018;Zhao et al, 2018;Zhang et al, 2020), Na 3 MSe 4 (M = P, Sb) series (Bo et al, 2016;Mahmoud et al, 2019), Na m M x P y X 12 (M = Si, Ge, Sn; X = S, Se; 10 ≤ m ≤ 11; x/y = 1/2 or 2) series (Kato et al, 2016;Richards et al, 2016;Wan et al, 2020), and Na 7 P 3 X 11 (X = O, S, Se) series (Wang et al, 2017). The most common in the Na 3 MS 4 (M = P, Sb) series is Na 3 PS 4 , which has two crystal forms: tetragonal (P −4 21 c; a = b = 0.69520 nm, c = 0.70757 nm) and cubic (I −4 3 m; a = b = c = 0.70699 nm) (Tanibata et al, 2017;Krauskopf et al, 2018a;Takeuchi et al, 2018;Zhao et al, 2018).…”

Nonaqueous Sodium‐Ion Full Cells: Status, Strategies, and Prospects

“…The structural flexibility and small volume change of amorphous materials may play a role in mitigating interface stress during cycles, but amorphization is so difficult to achieve for most high‐voltage cathode materials . Furthermore, combining the excellent properties of various electrolytes to form a composite electrolyte is a classic approach; for instance, Na 3 Zr 2 Si 2 PO 12 –Na 3 PS 4 composite ceramic electrolyte combines the good interfacial ability of the sulfide electrolyte and the high grain conductivity of the inorganic ceramic electrolyte . In addition to all inorganic composites, organic–inorganic composites have also been explored.…”