Facile synthesis and application of CuS nanospheres in aqueous and organic lithium ion batteries.

Monodispersed CuS nanospheres with a diameter of about 200 nm consisted of nanoplates have been hydrothermally synthesized via a facile process without any surfactant at 120 degrees C. The morphologies of the hierarchical CuS nanospheres were explored by X-ray diffraction, field emission scanning and transmission electron microscopy. In addition, CuS nanospheres cathode material for lithium-ion batteries were studied both in Organic and Aqueous phase. In organic electrolyte, the discharge capacity at first cycle with a cutoff voltage of 3-1.5 V is up to 628 mAh/g. When the voltage range is fixed from 1.8 to 2.6 V, the first discharge capacity reaches 225 mAh/g. After 30 cycles the discharge capacity has still kept at 90 mAh/g. On the other hand, it is well worth noting that here we first report the electrochemical behavior of CuS in aqueous lithium-ion batteries. In aqueous phase, different from other materials which have a drastic decay, it still keeps its initiative capacity 45 mAh/g after 100 cycles.