Synthesis and assessment of novel Na2S dispersed high performance nanocomposite gel polymer electrolyte intended for sodium batteries and electric double layer capacitors

• Published in: Journal of energy storage 2024-05, Vol.86, p.111280, Article 111280
• Main Authors: Patel, Maitri, Giri, Ranjan Kr, Mishra, Kuldeep, Chaudhari, J.J., Kanchan, D.K., Singh, Pramod K., Kumar, Deepak
• Format: Article
• Language: English
• Subjects: Electric double layer capacitor; Electrochemical impedance spectroscopy; Na2S nanoparticles; Nanocomposite gel polymer electrolyte; Sodium battery
• ISSN: 2352-152X; 2352-1538
• DOI: 10.1016/j.est.2024.111280

Sodium sulphide (Na2S) nanoparticles are synthesized by hydrothermal method and utilized for electrochemical application for the first time. A series of sodium-ion conducting nanocomposite gel polymer electrolytes (NCGPEs) incorporating poly (methyl methacrylate) i.e., (PMMA) as the polymer backbone, sodium tetrafluoro-borate (NaBF4) as the salt, tetraethylene glycol dimethyl ether (TEGDME) as the plasticizer, and Na2S as the active fillers, are fabricated and studied. The optimized electrolyte having PMMA/NaBF4/TEGDME matrix incorporated with 2.5 wt% Na2S nanoparticles exhibits a high ionic conductivity of 3.0 × 10−4 S cm−1, low activation energy of 0.13 eV and operating voltage range of ~2.8 V at ambient temperature. Thermal studies reveal that the fabricated NCGPEs have the ability to retain the gel phase up to 473 K. The X-ray diffraction (XRD) and Fourier transform Infra-red (FTIR) spectroscopy indicate changes in structure and the ion–filler–polymer interactions inside the synthesized NCGPEs. A proto-type sodium cell with an optimized NCGPE has an open circuit voltage of 2.3 V and a first discharge capacity of 205 mAh g−1. The electric double layer capacitor (EDLC) designed with optimized electrolyte has a specific capacitance of 58 F g−1 and is stable up to 2000 charge-discharge cycles. [Display omitted] •Na2S nanoparticles are synthesized by hydrothermal method and utilized for electrochemical application for first time.•Effect of Na2S nanoparticles on PMMA based Na+ conducting gel polymer electrolyte has been investigated.•The optimized nanocomposite with 2.5 wt% has a high ionic conductivity of 3.0 × 10−4 S cm−1.•Prototype sodium battery shows OCV of ∼2.3 V and delivers discharge capacity ∼205 mAh g−1.•Prototype EDLC has specific capacitance of 58 F g−1 and stable up to 2000 cycles.