Ph.D. Thesis, Postgraduate Institute of Science, University of Peradeniya (2000)

Supervisors: M. A. K. L Dissanayake (director@pgis.ac.lk), P. W. S. K. Bandaranayake (kumara@pdn.ac.lk), S. Skaarup (skaarup@kemi.dtu.dk) and K. West (kw@nano.ku.dk)

Solid polymer electrolytes based on polycrylontrile (Pan) and organically modified ceramics (Ormocers)
G. A. K. S. Perera (kumudu@wyb.ac.lk)

Pan based electrolytes were made by complexing EC and PC with different salts namely, CuCNS, CU (CF3SO3)2 Mg (CIO4)2 and LiCF3SO3 .Sample preparation was done using the hot pressed technique .All systems Yielded free standing electrolyte films.

System with 21 mol% PAN: 30 mol% EC: 45 mol% CuCNS has a room temperature conductivity of 3.3 x 10-5 S cm-1 while the system with 20 mol% PAN :41 mol% EC :34 molPC:5 mol% CU (CF3SO3)2 has a room temperature conductivity of 4.1x10-3 S cm-1Conductivity variation with temperature of the two system show Arrhenius and VTF behaviors  receptivity .Former system seems to be an anionic conductor and the latter system a mixed conductor with cationic and electronic contributions .Electrolytes made with    CU (CF3SO3)2 has been used in cells of the form ,Cu/PAN:EC:PC: CU (CF3SO3)2/PPy:DBS where DBS  for stands for polypyrrole polymerized in the presence of DBS .Open circuit voltage was approximately 180 mV.A Capacity 12μ Ah under a load resistor of KΩ was obtained .

When  Mg(CIO4)2 was incorporated with Pan : EC :PC,a room temperature conductivity of 3.2 x 10-3 S cm-1 can be obtained from the composition 18 mol% PAN :64 mol% EC:14 mol %PC :4mol%Mg (CIO4)2 /PPy :DBS .Open circuit voltage lies around 1.5 V. Estimated capacity values are around 0.18 mA h.

System based on LiCF3SO3 has a room temperature conductivity of 1.2 x 10 x 10-3 S cm-1Corresponding composition is 15 mol% PAN :42 mol EC :36 mol% PC :7mol%LiCF3 SO3 conductivity variation with temperature followed VTF behavior .Stability of the electrolyte with lithium is somewhat acceptable .Test cells in the configuration ,Li/PAN :EC :PC :LiCF3SO3/PPy :X(X:CF3SO3,DBS-,AS-) have open circuit voltage around 4 V It is possible to get more than 800 cycles with an efficiency of 99.95% Artificial muscles in the from. PPy: X/PAN: EC: PC:  LiCF3SO3/PPy: X(X: CF3SO3,DBS-) have been fabricated .Their movements were observed between two voltage .It is seen that the movements are faster when the assembly is thin

Ormocer electrolytes are having some what considerable conductivity values .But; those values should be enhanced further to make them proper candidates for applications. Concept of all solid cells may be feasible with ormocers.