Reducing Interfacial Resistance by Na-SiO₂ Composite Anode for NASICON-Based Solid-State Sodium Battery

Abstract

Room-temperature solid-state sodium batteries (SSBs) are viewed as one of the most promising candidates for next-generation energy storage devices because of their cost-effectiveness, safety performance, and high energy density. Na + ion superionic conductor (NASICON) type solid electrolyte (SE) shows great perspective due to its high ionic conductivity at room temperature. However, the high interfacial resistance between Na metal anode and NASICON SE is still thwarting the stable operation of SSBs. In this work, we successfully reduce the Na|NASICON interfacial resistance from 1658 to 101 Ω•cm 2 by lowering surface tension of Na metal via compositing Na metal with amorphous SiO 2 . Enabled by the enhanced interface contact, the solidstate Na-SiO 2 |NASICON|Na-SiO 2 symmetric cell can endure current density up to 500 μA/cm 2 and stably cycle for more than 135 h, while Na|NASICON|Na symmetric cell shorts in less than 10 h under 100 μA/cm 2 . This Letter provides an effective route to form close contact between Na metal anode and NASICON SE and fuels studies concerning Na|NASICON interface in the future.

Isotropous Sulfurized Polyacrylonitrile Interlayer with Homogeneous Na+ Flux Dynamics for Solid‐State Na Metal Batteries

“…Moreover, the total resistance starts to decrease until cycling at 1.0 mA cm −2 (Figure 3f and Figure S11c, Supporting Information) and ultimately shows a high CCD of 1.4 mA cm −2 , which to our best knowledge is the top‐level among reported NASICON‐based SSEs in published literatures up to now (Figure 3g). [ 37–41 ] It also shows excellent long‐term galvanostatic cycling stability at RT. As shown in Figure 3h, the Na/SPAN‐NASICON/Na cell delivers a stable cycling performance for up to 500 h at 0.1 and 0.25 mA cm −2 , further confirming the effective suppression of dendrites growth and highly improved cycling stability among anode–electrolyte interface.…”

Progress and Challenges for All‐Solid‐State Sodium Batteries

“…For example, a Na–SiO 2 composite electrode showed decreased surface tension and enhanced contact of the SE with Na metal. [ 179 ] As shown in Figure 17b, this composite electrode showed SE/Na metal charge‐transfer resistance that decreased to 101 − cm 2 , thereby achieving an excellent Na–SiO 2 /Na–SiO 2 symmetric cell. Besides oxides, MoS 2 also has been introduced for Na metal protection to enhance Na stripping.…”

“…Reproduced with permission. [ 179 ] Copyright 2020, American Chemical Society. c) Schematic illustration of Na x MoS 2 –C‐BASE triple interface and the electrochemical results for ASSBs.…”

NASICON‐Type Na3Zr2Si2PO12 Solid‐State Electrolytes for Sodium Batteries**

“…[65] Moreover, improving the wettability of sodium metal itself by forming alloys is also helpful for good sodium anode/SSE interface. Fu et al [66] fabricated a NaÀ SiO 2 composite anode by introducing amorphous SiO 2 into Na metal, which obtained reduced surface tension and got sufficient contact with NASICON SSEs compared with pristine Na metal (Figure 8d). The symmetric cell assembled by NASICON SSEs and NaÀ SiO 2 electrodes possessed dramatically reduced charge transfer resistance, which was mainly attributed to the improved physical contact between composite electrodes and SSEs.…”

“…Moreover, improving the wettability of sodium metal itself by forming alloys is also helpful for good sodium anode/SSE interface. Fu et al [66] . fabricated a Na−SiO 2 composite anode by introducing amorphous SiO 2 into Na metal, which obtained reduced surface tension and got sufficient contact with NASICON SSEs compared with pristine Na metal (Figure 8d).…”