A lithium polymer battery able to act as a super capacitor for rapid power delivery could be fielded within four years to enhance the performance of micro air vehicles.

The mass and volume of power sources are a limiting factor for micro air vehicles' endurance and payload capability, so the US Air Force Research Laboratory is funding battery research. It has awarded Denver-based ADA Technologies $100,000 to develop the lithium polymer battery that can also act as a capacitor. It would be used by micro air vehicles up to 1.36kg (3lb) in mass.

While a battery provides a consistent level of energy, capacitors are designed to deliver higher levels of power when needed - for take-off, for example - and for some payload functions and landing. A single power source that could act as battery and a capacitor would provide a mass saving.

In ADA Technologies' lithium polymer battery the electrode is "nanostructured," meaning it has features at the atomic scale that enable it to provide these multiple functions. "It has a large surface area at the electrode in relation to the electrolyte and more surface area means more power," says ADA Technologies' research and development programme manager Doug Campbell.

Batteries work through electron loss from the cathode to the anode via the electrolyte resulting in oxidation of the anode, but also in electron transfer to the circuit to which the battery is connected, providing electricity to its device.

Source: Flight International