A selenium@polypyrrole hollow sphere cathode for rechargeable lithium batteries

A selenium@polypyrrole hollow sphere composite cathode delivers a reversible specific discharge capacity of 400 mA h g(-1) after 80 cycles and a 60% reduction in impedance of the cycled cells is obtained. The soluble polyselenide species are demonstrated to be confined by PPy hollow spheres, thus inhibiting the shuttle effect to a large extent.