Free-Standing PEO/LiTFSI/LAGP Composite Electrolyte Membranes for Applications to Flexible Solid-State Lithium-Based Batteries

Abstract

Battery research has recently diverged into solid-state chemistry and flexible features to address the increasing demands in electric vehicles and novel electronics. In this study, we successfully fabricate 4-inch sized thin freestanding lithium-ion conducting composite electrolyte membrane. The solid electrolytes are made up of polyethylene oxide (PEO) lithiated with lithium bis(trifluoromethylsulphonyl)imide (LiTFSI) in which submicrometer sized crystalline Li 1.4 Al 0.4 Ge 1.6 (PO 4 ) 3 (LAGP) particles are homogeneously distributed. The impacts of the LAGP loading (20-60 wt%) on the thermal, electrical, and mechanical properties of the composite electrolytes are systematically assessed. The composite membranes exhibit similar conducting behavior of dry polymer electrolytes with two distinct ionic conduction mechanisms transitioned around the melting temperature. The conductivities of the composites are marginally lower than the polymer electrolyte with no LAGP. Addition of LAGP, compared with PEO/LiTFSI, has slightly increased thermal transition temperatures (both glass transition temperature and melting temperature) as well as the crystallinity of PEO. Increasing the amount of LAGP ceramic fillers increased the elastic modulus, reduced the strain to failure point, but has less impacts on the yielding strength. The freestanding ceramic/polymer composite electrolytes with optimal LAGP loading can result appropriate electrical, thermal and mechanical properties and hence, have potential applications to flexible all solid-state lithium-based batteries.

Solid‐State Lithium–Sulfur Battery Enabled by Thio‐LiSICON/Polymer Composite Electrolyte and Sulfurized Polyacrylonitrile Cathode

“…The result provides direct‐viewing of the high content of LGPS in LCE and their dense packing. In contrast to the majority of the composite electrolytes reported in the literature,33–35 the ceramic powders were uniformly distributed throughout the polymer matrix. The PEO polymer electrolyte in this work was embedded in continuously tightly packed LGPS electrolyte particles, and the ceramic particles no longer just function as “filler” for suppressing the crystallinity of the polymer matrix.…”

Sulfide and Oxide Inorganic Solid Electrolytes for All-Solid-State Li Batteries: A Review

“…For example, the use of phosphorous source (H 3 PO 4 ) as precursor provides the best LAGP phase purity and the highest ionic conductivity of ~5 × 10 −4 S cm −1 at 25 °C. In addition, few studies on the synthesis, conductivity (~4 × 10 −4 S cm −1 , see Table 3 [ 365 ]) and interface mechanisms, and physical and electrochemical properties of LAGP have been published since 2019 [ 49 , 342 , 394 , 395 , 396 , 397 , 398 , 399 , 400 , 401 , 402 , 403 , 404 , 405 , 406 , 407 , 408 , 409 , 410 , 411 , 412 , 413 , 414 , 415 , 416 , 417 , 418 , 419 , 420 , 421 , 422 , 423 , 424 , 425 , 426 , 427 , 428 , 429 , 430 , 431 , 432 , 433 , 434 ...…”

The synergistic effect of the PEO–PVA–PESf composite polymer electrolyte for all-solid-state lithium-ion batteries

“…All-solid-state lithium-ion batteries have aroused researchers' attention in recent years due to the impending demands of high safety and energy density. [1][2][3][4] One of the arduous challenges is developing an adequate solid electrolyte with high Li + conductivity, wide electrochemical windows and low interfacial resistance to afford outstanding electrochemical performances. The composite polymer electrolyte (CPE) based on PEO is a promising candidate owing to the low glass transition temperature (À60 C), high Li + solvation ability and admirable interfacial stability with lithium.…”

“…[5][6][7][8][9] However, the low room temperature conductivity (10 À7 to 10 À6 S cm À1 ), narrow electrochemical windows and inferior mechanical properties of PEO are the main obstacles for further development. 4,7,9 Blending is one of the valid approaches to ameliorate the properties of PEO, such as with PVP, 10 PVDF, 11 and PMMA; 12 this can decrease crystallization and enhance the fractional movement of polymer chains and the migration amount of Li + . 13 Similar to PEO, polyvinyl alcohol (PVA) is another semicrystalline polymer with the fascinating properties of nontoxic, water solubility and biocompatibility; it has been under the spotlight and applied as an electrolyte in supercapacitors on a large scale.…”