Self-Healing Single-Ion Conducting Triblock Copolymer Electrolytes for Sodium Batteries via RAFT Polymerization
Yuxuan Zhang1, Mokun Chen2, Théophile Pelras2, Katja Loos2, Giuseppe Portale1
1.Physical Chemistry of Polymeric and Nanostructured Materials, Zernike Institute for Advanced Materials, University ofGroningen
2.Macromolecular Chemistry and New Polymeric Materials, Zernike Institute for Advanced Materials, University of Groningen
Sodium metal batteries (SMBs) offer a promising alternative to lithium-ion batteries due to sodium’s abundance and cost-effectiveness [1]. However, the formation of sodium dendrites and limited ion transport efficiency in polymer electrolytes hinder their commercial viability.
To address these, we design a self-healing single-ion conducting polymer electrolyte via reversible addition–fragmentation chain transfer (RAFT) polymerization. The electrolyte is based on a A–B–C triblock copolymer architecture comprising three distinct functional blocks: Block A poly(sulphopropyl acrylate-sodium), which anchors immobilized sulfonate groups for single-ion conduction and mechanical rigidity; Block B poly(oligo ethylene glycol acrylate), which enhances ion mobility via flexible ethylene glycol chains[2]; and Block C poly(ureido pyrimidinone acrylate), which enables autonomous self-healing through quadruple hydrogen bonds[3].
The self-assembly of the triblock copolymer leads to microphase separation, forming continuous, high-speed ion conduction channels, achieving high ion conductivity [4]. The single-ion conduction eliminates anion polarization, homogenizing Na⁺ flux to suppress dendrite nucleation [5]. This design effectively mitigates sodium dendrite growth while ensuring mechanical stability and extended cycle life for SMBs.
This work pioneers a multifunctional electrolyte platform that simultaneously addresses SMBs’ key bottlenecks—dendrite growth, interfacial instability, and electrolyte degradation—while capitalizing on sodium’s inherent sustainability and scalability.