Facile synthesis of Fe-doped Sn4P3 anode materials for high-performance lithium-ion batteries

Metal doping plays a momentous role in heightening the electronic conductivity of Sn4P3. This work proposes the facile synthesis of Fe-doped Sn4P3 via a solid-state reaction process. The resulting Fe-doped Sn4P3 is stacked by a great quantity of nanoparticles. As the ionic radius of Fe3+ (64.5 p.m.) is slightly smaller than that of Sn4+ (69 p. m.), Fe3+can easily dope into the structure of Sn4P3. The Sn4P3 anode with 5% Fe doping delivers a larger initial discharge capacity of 1105.1 mAh/g and coloumbic efficiency of 86.2%. After 200 cycles, a high discharge capacity of 972.4 mAh/g is reached, while the discharge capacity of un-doped Sn4P3 anode merely maintains at about 423.3 mAh/g. As an inactive matrix, Fe atoms can disperse among Sn atoms, thus inhibiting the aggre-gation of Sn atoms during cycling. The results display that Fe doping in Sn4P3 structure is extremely vital to heighten the architecture stability and electrochemical performance. This facile solid-state reaction process can be enlarged to the manufacture of other metal-doped Sn4P3 in the field of lithium-ion batteries.