Solid-state high-resolution 13C and 7Li-NMR studies of poly(ethylene oxide)/lithium perchlorate/water complexes

A series of poly(ethylene oxide)(PEO)/LiClO_4 complex samples with different molar ratios were studied systematically by solid-state high-resolution()~(13)C and()~7Li-NMR spectroscopy.It was found that with the presence of a small amount of water(9%～16% by weight),the initial increase of LiClO_4 gradually destroys crystals formed by PEO,while further increase of LiClO_4 brings about the crystals formed by PEO and Li~+.When the molar ratio of PEO to LiClO_4 is in the range of 6/1 to 8/1,the complex samples are completely amorphous.The()~7Li-NMR results indicate clearly that the existence of water hinders the formation of Li~+-PEO crystals.