Hyperbranched Poly(Glycidol)‐Grafted Silica Nanoparticles for Enhancing Li‐Ion Conductivity of Poly(Ethylene Oxide)

Abstract

Silica nanoparticles bearing hyperbranched polyglycidol (hbP) grafts are synthesized and blended with poly(ethylene oxide) (PEO) for the fabrication of composite solid polymer electrolytes (SPEs) for enhancing Li‐ion conductivity. Different batches of hbPs are prepared, namely, the 5th, 6th, and 7th with increasing molecular weights using cationic ring‐opening polymerization and grafted the hbPs onto the silica nanoparticles using quaternization reaction. The effect of end functionalization of hbP‐grafted silica nanoparticles with a nitrile functional group (CN–hbP–SiO2) on the ionic conductivity of the blends with PEO is further studied. High dipole moments indicate polar nature of nitriles and show high dielectric constants. Among all the hbPs, the 6th‐batch CN–hbP–SiO2 nanoparticles exhibit better ionic conductivity on blending with PEO showing ionic conductivity of 2.3 × 10−3 S cm−1 at 80 °C. The blends show electrochemical stability up to 4.5 V versus lithium metal.

Recent Development in Topological Polymer Electrolytes for Rechargeable Lithium Batteries

“…Reproduced with permission. [ 51 ] Copyright 2020, Wiley‐VCH GmbH. c) Chemical structure of PAMAM, illustration of lithium polysulfide adsorption and Li + transport through PAMAM, and schematic illustration of PAMAM grafting on CNTs via esterification.…”

“…Mallela et al used silica nanoparticles (SiO 2 ) grafted with hyperbranched polyglycidol to prepare the composite solid polymer electrolyte (Figure 4b), improving the ionic conductivity, electrochemical stability, and dimensional stability of the electrolyte due to the introduction of silica. [51] Besides silica, the carbon nanotubes are also effective additive. Li et al grafted hyperbranched poly(amidoamine) on hydroxylated carbon nanotubes (PAMAM-CNTs) as multifunctional interlayer for lithium batteries (Figure 4c).…”

“…b) Synthesis of hyperbranched polyglycidol capped silica nanoparticles. Reproduced with permission [51]. Copyright 2020, Wiley-VCH GmbH.…”

Designing Polymer Electrolytes via Ring‐Opening Polymerization for Advanced Lithium Batteries

“…By functional modification of SiO 2 surface and combination with hyperbranched poly(glycidol)-grafted SiO 2 nanoparticles prepared by cationic ROP, Mallela et al prepared hyperbranched poly(glycidol)-grafted silica nanoparticles, which were compounded with PEO electrolyte and significantly improved the ionic conductivity and electrochemical stability of the electrolyte. [112] Attempts have also been made to prepare organic-inorganic composite electrolytes by mixing inorganic electrolytes, such as LLZTO with diethylene gly-col diglycidyl ether and using LiPF 6 as an initiator to initiate monomer cationic ROP (Figure 9b). Compared with the pure SPE, the electrochemical performances were strongly improved.…”

Electrospun Polyethylene Oxide (PEO)-Based Composite polymeric nanofiber electrolyte for Li-Metal Battery

“…Therefore, the interaction between the two is beneficial to reduce the regularity of PEO macromolecular chains, thus promoting the lithium ion transport in the system [18]. (2) There is a dipole-dipole effect between the polymer matrix and ceramic additives, which also inhibits PEO crystallization with improved carrier mobility [19]. (3) The high porosity and three-dimensional (3D) network structure of the ASPNEs are beneficial to the rapid transmission of lithium ions, thus improving the ionic conductivity [20].…”