Polymer Electrolytes for Lithium-Ion Batteries

Abstract

The motivation for lithium battery development and a discussion of ion conducting polymers as separators begin this review, which includes a short history of polymer electrolyte research, a summary of the major parameters that determine lithium ion transport in polymer matrices, and consequences for solid polymer electrolyte development. Two major strategies for the application of ion conducting polymers as separators in lithium batteries are identified: One is the development of highly conductive materials via the crosslinking of mobile chains to form networks, which are then swollen by lithium salt solutions ("gel electrolytes"). The other is the construction of solid polymer electrolytes (SPEs) with supramolecular architectures, which intrinsically give rise to much enhanced mechanical strength. These materials as yet exhibit relatively common conductivity levels but may be applied as very thin films. Molecular composites based on poly(p-phenylene)- (PPP)-reinforced SPEs are a striking example of this direction. Neither strategy has as yet led to a "breakthrough" with respect to technical application, at least not for electrically powered vehicles. Before being used as separators, the gel electrolytes must be strengthened, while the molecularly reinforced solid polymer electrolytes must demonstrate improved conductivity.

All‐Solid‐State Lithium‐Ion Microbatteries: A Review of Various Three‐Dimensional Concepts

“…Several extensive reviews give a more detailed description of the different types of polymer electrolytes and their development. [125][126][127] Polymer electrolyte fi lms can be produced using various methods. It was reported that electrolyte fi lms could, for example, be prepared by casting from a polymer solution, [ 128 ] evaporation methods, [ 129 ] or in situ plasma polymerization techniques.…”

Intrinsically Stretchable Supercapacitors Composed of Polypyrrole Electrodes and Highly Stretchable Gel Electrolyte

“…Compared to liquid electrolyte, polymer electrolytes have several advantages over liquid electrolytes including the ability to minimize percent leakage of electrolytes and ensure non-flammable reaction products at the surface of electrodes. [22][23][24] They have been widely used in energy conversion and storage devices. [25][26][27][28] Currently, there are only a few stretchable solid electrolytes reported such as graft copolymer poly[(oxyethylene) 9 Very recently, a stretchable H 2 SO 4 -PVA gel electrolyte has been used to prepare stretchable integrated supercapacitor which can sustain 120% strain.…”

A single-ion gel polymer electrolyte based on polymeric lithium tartaric acid borate and its superior battery performance

“…(iii) Improvement of safety, in addition to suppression of lithium dendrites, the quasi-solid-state construction of a polymer electrolyte is more tolerant to mechanical deformation. (iv) Better shape flexibility and manufacturing integrity [10][11][12][13][14][15][16][17]. Meanwhile, to be successfully used in practice, GPE must meet the following basic requirements: (i) ionic conductivity higher than~10 −4 S cm −1 at room temperature, (ii) lithium ion transference number close to unity, (iii) good thermal, chemical and electrochemical stability and (iv) a considerable mechanical strength [10,12,[18][19][20][21].…”