Electroactive polymers rechargeable batteries

Technically important electrochemical reactions of pyrrole and thiophene involve oxidation in non-nucleophilic solvents when the radical-cation intermediates react with the neutral molecule causing polymer growth [169, 191], Under controlled conditions polymer films can be grown on the anode surface from acetonitrile. Tliese films exhibit redox properties and in the oxidised, or cation doped state, are electrically conducting. They can form the positive pole of a rechargeable battery system. Pyrroles with N-substituents are also polymerizable to form coherent films [192], Films have been constructed to support electroactive transition metal centres adjacent to the electrode surface fomiing a modified electrode,... 

The capability of polypyrrole to be reversibly doped and dedoped by electrochemical methods makes this electroactive material adequate for the construction of rechargeable batteries [181-185]. The electroactive polymer can be either the anode or the cathode of the cell, although construction of anodes is most common, due to difficulties in inserting negative charges into polyheterocycles. Technical factors such as cyclability, energy density, and stability have to be optimized in the future, before commercial application of polypyrrole-based batteries. 

Battery designs using electroactive polymers feature the EAP as the cathode, which is separated from an anode (such as Li, Na, Mg, and Zn) by an electrolyte. Normally, high specific energies of up to 3.5 V can be obtained (409). EAPs that have been used in rechargeable batteries include polyacetylene-, PANI-, PPy-, PT-, and PPP-based materials (410). The current drawback to full utilization of EAPs for rechargeable batteries is the rate limitations associated with low ionic mobilities of the polymers as well as the electrolytes (14). 

These electroactive polymers are being investigated intensively in some industrial companies as electrode materials in rechargeable batteries. The following polymers and their derivatives are interesting PAn >, pp 80.232-234) ... 

The capability of polypyrrole to be reversibly doped and dedoped by electrochemical methods makes this electroactive material a candidate for the construction of rechargeable batteries. A number of battery designs using conducting polymers have been described... 

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