Gel Polymer Electrolyte with High Li⁺ Transference Number Enhancing the Cycling Stability of Lithium Anodes

Abstract

Lithium anodes suffer from severe safety problems in liquid electrolyte systems that result from an unstable Li plating/ stripping process and Li dendrite growth, leading to rapid degradation of Li metal batteries. A polyethylene (PE)-supported gel polymer electrolyte (GPE) with excellent electrolyte uptake/retention capability was simply prepared in this paper by the construction of cross-linked polymer networks (PNs) on the surface of a poly-(ethylenimine)-primed PE separator to stabilize the lithium anode. The highly delocalized negative charge of p-styrene sulfonate groups on PNs plays a role in regulating the Li + and anion transport, giving rise to a high Li + transference number. This GPE extended the electrochemical stability to 4.8 V and improved the stability of interface between the electrolyte and lithium metal anode (reduced overpotential and suppressed lithium dendrites) during storage and repeated lithium plating/stripping cycling. The Li metal anode-based battery employing this GPE exhibits excellent cycling stability and C-rate capability.

Organoboron‐Containing Polymer Electrolytes for High‐Performance Lithium Batteries

“…[54,55] The inevitable process of ex situ methods is that the obtained dry polymer membranes are soaked in LEs to get GPEs. [56] In a representative in situ process, a stoichiometric ratio of the monomers and initiator is dissolved in a LE to form a precursor solution. Then, polymerization of monomers is initiated to generate PEs under certain situations, where the LE is homogeneously immobilized within the polymer structures to obtain the GPEs.…”

Transference Number Determination in Poor-Dissociated Low Dielectric Constant Lithium and Protonic Electrolytes

“…Copolymer electrolytes [161][162][163][164][165], a crosslinked system based on methoxy compounds [155,[166][167][168], plasticized electrolytes or polymers enhanced by mesoporous ceramic fillers [45,61] were successfully analyzed by Bruce-Vincent method. Reasonable values of transference number were obtained as well for quasi liquid systems like ionic liquids [169][170][171] or much more complex systems with porous polymeric membrane enhancing cationic conductivity [172][173][174]. Bruce-Vincent method is as well successfully applied in single ion-conducting polymer electrolytes [175][176][177][178][179] The simplicity of the method makes it most widely used amongst all.…”

Porous Polymer Gel Electrolytes Influence Lithium Transference Number and Cycling in Lithium-Ion Batteries

“…There are a few recent studies that show that utilizing a liquid electrolyte in conjunction with a porous polymer structure can provide desirable transport properties and cycling performance in different lithium battery configurations [10][11][12][13][14]. Helms and colleagues reported a cation transference number of 0.72 for a nanoconfined polymer electrolyte based on a polymer of intrinsic microporosity (PIM) coated on lithium metal in 1 M LiTFSI and 0.2 M LiNO 3 (DOL-DME 1:1 v%) electrolyte [10].…”

“…The porous polymer electrolyte was used in the Li/S configuration, and the cell displayed over 98% Coulombic efficiency over 100 cycles. Wang and colleagues used a similar crosslinked polymer as a coating on a polyethylene separator, in the presence of 1 M LiPF 6 (EC-EMC-DEC) [13]. The transference number was 0.72 along with 10 −4 S cm −1 ionic conductivity at room temperature.…”