The device 9, wherein the medium is selected to facilitate diffusion of {HEAD ~ intercalating ions} between {TAIL ~ the first and second electrodes} 
between
The device 9 , wherein the medium is selected to facilitate diffusion of { HEAD ~ intercalating ions } between { TAIL ~ the first and second electrodes }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL