Single and multilayer composite electrolytes for enhanced Li-ion conductivity with restricted polysulfide diffusion for lithium–sulfur battery

• Published in: Materials today energy Vol. 33; p. 101274
• Main Authors: Park, Haeryung, Le Mong, Anh, Kim, Dukjoon
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.04.2023
• Subjects: Composite electrolyte; Ionic conductivity; Lithium–sulfur battery; Multilayer; Polysulfide; Polysulfide; Composite electrolyte; Multilayer; Lithium–sulfur battery; Ionic conductivity
• ISSN: 2468-6069; 2468-6069
• DOI: 10.1016/j.mtener.2023.101274

Lithium–sulfur battery is a promising energy source to achieve high energy density at low cost, but its commercialization has been being impeded by a few huddles associated with Li dendrite growth, polysulfide shuttle, and flammability, due to the utilization of liquid electrolytes. In this study, the single- and multi layered flexible composite electrolytes comprising organic poly(arylene ether sulfone)-g-poly(ethylene glycol) and inorganic Li6PS5Br nanoparticles are designed. Both composite electrolyte membranes exhibit excellent mechanical flexibility and thermal stability up to 200 °C. The single-layer composite electrolyte illustrates high ionic conductivity of 2.4 ⅹ 10−3 S/cm because of the self-assembled poly(ethylene glycol) domains accommodating large amount of free charge carriers. Even though the multilayer electrolyte membrane shows slightly lower conductivity of 8.7 ⅹ 10−4 S/cm, it provides quite high lithium-ion transference number of 0.81 with self-extinguishing ability and effective suppression of Li dendrite growth and polysulfide diffusion because of the highly selective Li6PS5Br layer. Accordingly, the Li/S cell assembled with multilayer composite electrolyte shows outstanding cyclic stability retaining 99.2% after 100 cycles at 0.1 C-rate. Those results demonstrate the application possibility of the prepared solid electrolytes for high safety and high performance lithium–sulfur battery. [Display omitted] •High lithium-ion conductivity (σ = 8.7 × 10−3 S/cm, tLi+ = 0.81) of solid electrolyte.•Excellent electrochemical stability (5.0 V vs. Li+/Li) and self-extinguishment.•Excellent suppression of Li dendrite growth and polysulfide diffusion.•Lithium–sulfur battery performance of 960 mAh/g with cyclic stability (99.2% after 100 cycles).