Amorphous GeSnSe nanoparticles as a Li-Ion battery anode with High-Capacity and long cycle performance.

ABSTRACT

A new ternary amorphous GeSnSe (GSS) nanopowder was effectively synthesized by using ball milling under inert atmosphere. Its topographical, microstructural and elemental characterizations revealed the formation of nanoparticles with undefined shape, short-range order and the tailored stoichiometry. Remarkably, this novel amorphous material demonstrates its competences as a promising Li-ion host anode, exhibiting a high cycle performance with a specific charge capacity of 963 mAh g-1 at an applied C-rate of 0.2C with a coulombic efficiency > 99.4 % after 300 cycles. Its high specific capacity, large rate capability, acceptable capacity retention and long cycle life could be attributed to a dual Li-ion storage mechanism that consists mostly of multiple reversible electrochemical processes as conversion and alloying reactions and capacitive processes. Moreover, its stable volume expansion (34 %), moderate electrode polarization (248.9 mV), reasonable charge transfer resistance (83 Ω) and apparent Li-ion diffusion coefficients between 10-9 - 10-14 cm2 s-1 could be promoted by a synergistic effect between Ge (capacity), Sn (conductivity) and Se (stability), which plays an important role on the stability and high cycle performance of the promising GSS-based anode.