Electrodeposited multiphase Sb, SbSn, Cu2Sb composite with superior chemical buffering as negative electrode for lithium-ion batteries: Effect of composition on lithiation behavior of Sb-Sn-Cu alloys

Antimony-tin ternary alloys outperform graphite as negative electrodes for lithium-ion batteries, offering significantly higher gravimetric and volumetric capacities. These alloys, conductive without additives, can be electrodeposited without binders, enhancing cell design and capacity. Based on bath composition, Sn-rich or Sb-rich SbSnCu ternary alloys can be synthesized which undergoes active-active-inactive chemical buffering during lithiation. The Sb-rich alloys show better stress buffering due to more lithiation/delithiation peaks and better use of lithium-inactive copper. This study finds Sb-rich alloys exhibit superior structural stability and electrochemical performance, delivering 374 mAh g(-1) at 200 mA g(-1) after 100 cycles, while Sn-rich alloys show substantial capacity fading, retaining only 113 mAh g(-1). The Sb-rich alloy maintains structural integrity, losing only 20 % capacity over the last 80 cycles, compared to 48 % loss in capacity during the 50-80th cycles in Sn-rich alloys.