More Like this

1. Organic–inorganic hybrid electrolytes from ionic liquid-functionalized octasilsesquioxane for lithium metal batteries

   https://doi.org/10.1039/C7TA04599A  

   Yang, Guang; Chanthad, Chalathorn; Oh, Hyukkeun; Ayhan, Ismail Alperen; Wang, Qing (January 2017, Journal of Materials Chemistry A)

   The use of highly conductive solid-state electrolytes to replace conventional liquid organic electrolytes enables radical improvements in the reliability, safety and performance of lithium batteries. Here, we report the synthesis and characterization of a new class of nonflammable solid electrolytes based on the grafting of ionic liquids onto octa-silsesquioxane. The electrolyte exhibits outstanding room-temperature ionic conductivity (∼4.8 × 10 −4 S cm −1 ), excellent electrochemical stability (up to 5 V relative to Li + /Li) and high thermal stability. All-solid-state Li metal batteries using the prepared electrolyte membrane are successfully cycled with high coulombic efficiencies at ambient temperature. The good cycling stability of the electrolyte against lithium has been demonstrated. This work provides a new platform for the development of solid polymer electrolytes for application in room-temperature lithium batteries. 

   more » « less
2. High-performance all-solid-state batteries enabled by salt bonding to perovskite in poly(ethylene oxide)

   https://doi.org/10.1073/pnas.1907507116  

   Xu, Henghui; Chien, Po-Hsiu; Shi, Jianjian; Li, Yutao; Wu, Nan; Liu, Yuanyue; Hu, Yan-Yan; Goodenough, John B. (September 2019, Proceedings of the National Academy of Sciences)

   Flexible and low-cost poly(ethylene oxide) (PEO)-based electrolytes are promising for all-solid-state Li-metal batteries because of their compatibility with a metallic lithium anode. However, the low room-temperature Li-ion conductivity of PEO solid electrolytes and severe lithium-dendrite growth limit their application in high-energy Li-metal batteries. Here we prepared a PEO/perovskite Li 3/8 Sr 7/16 Ta 3/4 Zr 1/4 O 3 composite electrolyte with a Li-ion conductivity of 5.4 × 10 −5 and 3.5 × 10 −4 S cm −1 at 25 and 45 °C, respectively; the strong interaction between the F − of TFSI − (bis-trifluoromethanesulfonimide) and the surface Ta 5+ of the perovskite improves the Li-ion transport at the PEO/perovskite interface. A symmetric Li/composite electrolyte/Li cell shows an excellent cyclability at a high current density up to 0.6 mA cm −2 . A solid electrolyte interphase layer formed in situ between the metallic lithium anode and the composite electrolyte suppresses lithium-dendrite formation and growth. All-solid-state Li|LiFePO 4 and high-voltage Li|LiNi 0.8 Mn 0.1 Co 0.1 O 2 batteries with the composite electrolyte have an impressive performance with high Coulombic efficiencies, small overpotentials, and good cycling stability. 

   more » « less
3. Ion Pair Integrated Organic‐Inorganic Hybrid Electrolyte Network for Solid‐State Lithium Ion Batteries

   https://doi.org/10.1002/ente.201800431  

   Yang, Guang; Fan, Baoyan; Liu, Feihua; Yao, Fangzhou; Wang, Qing (November 2018, Energy Technology)

   Abstract A class of organic‐inorganic hybrid electrolyte with ion pair integrated network (X‐POSS‐IL‐LiTFSI) has been prepared by crosslinking of oligomeric octasilsesquioxanes grafted with imidazolium‐based ionic liquids for solid state lithium ion battery applications. X‐POSS‐IL‐LiTFSI is thermally stable and highly amorphous, and shows high ionic conductivities and excellent electrochemical stability. With further immobilization of a small fraction of ionic liquid, the ionic conductivity of X‐POSS‐IL‐LiTFSI has been significantly improved, e. g. 1.4×10⁻⁴ S/cm at ambinet temperature, to the level required by the practical battery applications, while maintaining the demensional integity. The coin cells of lithium batteries with the plasticized X‐POSS‐IL‐LiTFSI electrolytes exhibit high specific capacities at both ambient and elevated temperatures. 

   more » « less
4. Non-solvating, side-chain polymer electrolytes as lithium single-ion conductors: synthesis and ion transport characterization

   https://doi.org/10.1039/c9py01035a  

   Liu, Jiacheng; Pickett, Phillip D.; Park, Bumjun; Upadhyay, Sunil P.; Orski, Sara V.; Schaefer, Jennifer L. (January 2020, Polymer Chemistry)

   Solid-state single-ion conducting polymer electrolytes have drawn considerable interest for secondary lithium batteries due to their potential for high electrochemical stability and safety, but applications are limited by their low ionic conductivities. Specifically, poly(ethylene oxide) (PEO) based electrolytes have the highest reported Li + conductivities for these materials; however, their potential is limited due to the ion transport mechanism being coupled to segmental relaxations of the cation solvating polymer chain. To investigate the potential of single-ion conducting polymer electrolytes lacking polar matrices, we synthesized three para -polyphenylene-based, side-chain polymer electrolytes with various pendent anion chemistries (–SO 3 − , –PSI − , and –TFSI − ) with differing binding affinities to Li + . Compared with the previously reported lithium poly(4-styrenesulfonyl(trifluoromethylsulfonyl)imide) (LiPSTFSI), the side-chain polymers showed at least 3 orders of magnitude higher conductivity with the same –TFSI − anion (6.7 × 10 −6 S cm −1 compared with 1.2 × 10 −10 S cm −1 at 150 °C). We found that the side-chain electrolyte showed a dielectric relaxation dominated transport mechanism through use of dielectric spectroscopy analysis. The conductivity is highly dependent on the charge delocalization and size of the pendent anion, which provides a pathway forward for the engineering of polymeric ion conductors for electrochemical applications. 

   more » « less
5. Segmented Phosphonium Ionenes As Solid Polymer Electrolytes for Lithium Ion Batteries

   https://doi.org/10.1149/MA2020-01522889mtgabs  

   Strong, Kayla; Abdulahad, Asem (May 2020, ECS Meeting Abstracts)

   All-solid-state lithium ion batteries replace the traditional liquid electrolyte with a conductive solid polymer electrolyte. Replacing the liquid electrolyte in batteries has the potential to improve safe use of batteries without the need for hermetic sealing, extending the operating temperature range, and extending the lifetime of the battery. However, solid polymer electrolytes often have non-competitive conductivity compared to liquid electrolytes. Improving the conductivity of solid polymer electrolytes based on an understanding of structure-property relationships is not yet well understood, but it is believed to depend heavily on the localized segmental motion of polymer chains. This work attempts to describe the role of polymer segmental motion on lithium ion transport through the synthesis and characterization of phosphonium ionenes that include poly(ethylene oxide) “soft” segments. Synthetically, these segmented polymers offer an opportunity to systematically control the segmental motion of polymer chains (i.e. glass transition temperature) through control of PEO incorporation. Prepared by step-growth polymerization, these segmented phosphonium ionenes achieve molecular weights up to 40,000 g/mol. Also, the degradation and glass transition temperatures are dependent on the percent incorporation of PEO as determined by thermogravimetric analysis and differential scanning calorimetry, respectively. The ability to influence the physical properties of this unique class of polyelectrolyte provides a unique opportunity to systematically probe the impact of glass transition temperature on the ion transport properties of solid polymer electrolytes in lithium ion batteries. Our initial results from electrochemical impedance as well as the charge/discharge performance of these novel solid polymer electrolytes in coin cell battery assemblies will also be presented. 

   more » « less