Electrochemical performance of SnSb and Sn/SnSb nanosize powders as anode materials in Li-ion cells

Nanosized pure SnSb and SnSb with excess ductile Sn (referred to as Sn/SnSb) powders have been synthesised by careful reductive co-precipitation in NaBH4. Crystallite sizes for both powders measure in the 50-100 nm range with particles agglomerating up to a few micrometers in pure SnSb powder and several tens of micrometers in the Sn/SnSb composite. Pristine powders were mixed separately with carbon black in order to improve dispersion and electronic conduction. Electrodes were constructed using the powders and tested as Li-ion half cell in order to measure the electrochemical performance. The energy storage capacity of electrodes improved in excess of 50% by increasing quantity of carbon black from 20 wt.% to 50 wt.%. Capacity fade over repeated charge and discharge cycles still remains a challenge to practical application of SnSb and Sn/SnSb alloy electrodes.