Much work has been reported on ion conduction in solid solutions of sa
lts dissolved in linear and comb-branched poly(ethylene oxide) analogu
es. There appears to be a limit to the conductivity levels achieved in
such systems, and conductivity values rarely exceed sigma similar to
10(-4) Scm(-1) at room temperature. To overcome this there has been a
move towards more mobile plasticized systems and polymer gel electroly
tes are receiving some attention. Gels prepared from N-methyl-2-pyrrol
idinone/LiCl and polyglucosans such as cellulose and amylose have been
studied and show some promise with ambient sigma greater than or equa
l to 10(-4) Scm(-1). Macroporous polyethylene has also been used to su
pport fluid polyethylene glycol/salt systems, but these only reached s
igma greater than or equal to 10(-5) Scm(-1) at ambient temperature. C
omb-branch polymers with crown ethers provide systems with respectable
room temperature conductivities of between 10(-4) and 10(-5) Scm(-1),
but these might be improved if the crown ethers could be arranged in
regular channels. Ways to achieve this are briefly discussed.