Solid electrolytes polyether-based polymers

Fauvarque was granted a patent on aqueous alkaline solid electrolyte based around polyether polymer matrices [92]. 

Some vinyl fluoride-based polymers with side chains of perfluorosulfonic acid (the Nation family) are important ion-exchange membrane materials used in practice for electrolysis of NaCl and in certain fuel cells. They show a proton conductivity of 0.01 S cm- at room temperature. However, such fast ionic transport occurs only when they are swollen with water. It is therefore not appropriate to call them solid electrolytes in the tme sense of the word. It was in 1970 that anionic conductivity, though not high, was reported for crown ether complexes such as dibenzo-18-crown-6 KSCN, in which cations are trapped by the ligand. " A few years later much higher cationic (instead of anionic) conduction was found in complexes of a chain-like polyether such as PEO or PPO with alkaline salts here, PEO stands for poly(ethyleneoxide), (CHjCHj-O), and PPO for poly(propyleneoxide)."2>"3 These were the flrst examples of tme polymer solid electrolytes and were followed by a great number of studies. Polymeric electrolytes are advantageous in practice because they are easily processed and formed into flexible Aims. 

MURATA K (1995), An overview of the research and development of solid polymer electrolyte batteries , Electrochim Acta, 40 2177-2184 NiSHiMOTO A, WATANABE M, iKEDA Y and KOHJiYA s (1998), High ionic conductivity of new polymer electrolytes based on high molecular weight polyether comb polymers , Electrochim Acta, 43(10-11) 1177-1184 OH B and KIM Y R (1999), Evaluation and characteristics of a blend polymer for a solid polymer electrolyte . Solid State Ionics, 124 83-89 OMATA T and MAKOTO K (1998), Lithium ion-conductive polymer electrolyte and lithium ion battery , European Patent No.0854527 OWENS B B and Osaka t (1997), Panel discussion future prospects of lithium batteries , J Power Sources, 68 173-186... 

Chin Han Chan, PhD, is an associate professor at the Faculty of Applied Sciences, Universiti Teknologi MARA [MARA University of Technology) in Selangor, Malaysia. She has received many research grants, has published many articles in professional journals, has published chapters in books, and has presented at many professional conferences. Her field of interest includes epoxidized natural rubber-based nanostructured blends, thermoplastic elastomer, biodegradable polyester/polyether blends, and solid polymer electrolytes. 

She has pnbhshed more than 45 papers in intematiorral and national refereed journals, more than 60 publications in conference proceedings, and more than 20 invited lectures for international conferences. She has been one of the editors of Malaysian Journal of Chemistry, Berita IKM- Chemistry in Malaysia, and books pnbhshed by Royal Society of Chemistry entitled Natural Rubber Materials, Volume 1 Blends and IPNs and Volume 2 Composites and Nanocomposites. She peer-reviews a few international journals on polymer science. Her research interest is devoted to modified natural rabber-based thermoplastic elastomers, biodegradable polyester/polyether blends, and solid polymer electrolytes... 

Here, the polymeric species are designed to interact with Li salts, leading to the necessary ionic separation for electrolyte systems, and therefore, the presence of hquid solvents can be avoided. In order to obtain dissolution of Li salts, the polymers have to contain ethers, ester or other polar groups. Indeed, the most important polymeric electrol) es of this kind are based on polyethylene oxide and its derivatives [36 ]. These polymers have the reactivity of ethers towards Li and Uthiated carbon surfaces, which is much lower as compared with that of alkyl carbonates. However, since battery systems with solid-state electrolyte matrices are usually operated at elevated temperatures (>60 °C), it is obvious that there are surface reactions between the polyethers and the Uthiated carbons which form of surface films. We should also mention problems of hmited electrochemical windows when using solvent-free polymeric electrolytes, since the oxidation potentials of polyethers are similar to those of ethers which are usually in the 4-5 V range (v5. 

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