Every battery we know has an anode, a cathode, some electrolyte, and a case enclosing it. The anode and cathode work together to produce energy from the battery cell. The anode begins the process by releasing its electrons to the external circuit. While the cathode receives these at the other end of that loop. However, the efficiency of the process depends on how well the two electrodes team up.
Considerations for the Anode and Cathode
The Best Material for the Anode
The anode oxidizes during the electrochemical reaction we described above. Therefore it follows it should be an efficient reducing agent, with good conductivity, and well able to release its electrons. Materials such as zinc and lithium meet these criteria. Ideally they should also be stable and easy to work with.
The Best Material for the Cathode
The cathode, on the other hand reduces during the chemical reaction. It follows it should be an efficient oxidizing agent, with a useful working voltage, and stable when in contact with the electrolyte. Metallic oxides are common cathode materials. They should also be stable and easy to work with.
The Most Desirable Cathode and Anode Combinations
Department.Washington.Edu confirms the ideal anode and cathode combinations produce lightweight cells, with high voltage and capacity. However, the best in theory may prove impractical on account of real issues, and reactivity with other components. Cost too, may prove prohibitive.
Brief Considerations for the Electrolyte
Electrolyte provide safe passage for the ions to travel between the electrodes inside the battery. They were originally liquid solutions, although solid versions are proving effective alternatives.
It follows that electrolytes need to have strong ionic conductivity, with zero reactivity to electrode materials. They should also be able to tolerate temperature fluctuations. Effective aqueous solutions include dissolved salts, acids, and alkalis. Although this again is a dynamic situation.
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