Regulating Na‐ion Solvation in Quasi‐Solid Electrolyte to Stabilize Na Metal Anode

Abstract

Sodium metal batteries are promising for cost‐effective energy storage, however, the sluggish ion transport in electrolytes and detrimental sodium‐dendrite growth stall their practical applications. Herein, a cross‐linking quasi‐solid electrolyte with a high ionic conductivity of 1.4 mS cm−1 at 25 °C is developed by in‐situ polymerizing poly (ethylene glycol) diacrylate‐based monomer. Benefiting from the refined solvation structure of Na+ with a much lower desolvation barrier, random Na+ diffusion on the Na surface is restrained, so that the Na dendrite formation is suppressed. Consequently, symmetrical Na||Na cells employing the electrolyte can be cycled >2000 h at 0.1 mA cm−2. Na3V2(PO4)3||Na batteries reveal a high discharge specific capacity of 66.1 mAh g−1 at 15 C and demonstrate stable cycling over 1000 cycles with a capacity retention of 83% at a fast rate of 5 C.

Li, Na, K, Mg, Zn, Al, and Ca Anode Interface Chemistries Developed by Solid‐State Electrolytes

“…Table 1 provides the state‐of‐the‐art multivalent SEs and their properties. [ 10–12,32,39,102,112–232 ]…”

“…Zhou et al. [ 197 ] presents in situ polymerized poly (ethylene glycol) diacrylate‐based electrolytes with σ Na + ≈1.4 mS cm −1 at 25 °C. The refined solvation structure of Na + restrains the random diffusion of Na + ‐ions due to lower desolvation energy barriers with suppression of dendritic growth over >2000 h Na//Na cells.…”

“…[195,196] Various complexes of PEO with Li, Na, K, Zn, Mg, and Al (i.e., NaSCN, NaTFSi, NaPF 6 , NaYF 6 , KYF 6 , LiSO 3 SF 3 , LiTFSI, LiFSi, ZnTFSI 2 , MgTFSI, AlCl 3 ) have been explored for SPEs. [32,102,[179][180][181][182][183][184][185][186][187][188][189][190][191][192][193][194][195][196] Zhou et al [197] presents in situ polymerized poly (ethylene glycol) diacrylate-based electrolytes with 𝜎 Na + ≈1.4 mS cm −1 at 25 °C. The refined solvation structure of Na + restrains the random diffusion of Na + -ions due to lower desolvation energy barriers with suppression of dendritic growth over >2000 h Na//Na cells.…”

Polymer-based electrolytes for solid-state lithium batteries with a wide operating temperature range

“…Numerous interactions exist in these systems, including iondipole interactions and dipole-dipole interactions, and it is difficult to describe this process with a simple model. [40][41][42][43] Therefore, unraveling the transport processes of Li + at different temperatures and developing novel models to decoupled superionic systems is another potential direction for advancement of solid-state lithium batteries with a wide operating temperature range.…”

Regulating Micro‐phase Structure in Plastic Crystal Gel Polymer Electrolyte for Quasi‐Solid‐State Lithium Metal Batteries

“…This strong interaction can confine and guide the migration of Li + , and inhibit the random diffusion of Li + on the surface of Li anode and the undesirable accumulation on the tips effectively. [34,48] Based on this knowledge, the Li anode cycled with PCGPE10-1 is expected to deliver enhanced interfacial kinetics and uniform plating and stripping behavior.…”