Continuance is a rechargable battery concept by Haimo Bao, Hailong Piao, Yuancheng Liu & Xiameng Hu. It redesigns the traditional AA battery by putting a USB port on it. This way, the battery can be charged via a USB connection or the device can be used to charge mobile and other devices via USB.
It doesn’t seem very practical. You would lose some of the battery capacity just by putting the USB port in the battery. But it is still neat. Maybe in the future this could work very well.