Enhanced reaction kinetics and structure integrity of Ni/SnO2 nanocluster toward high-performance lithium storage
SnO2 is regarded as one of the most promising anodes via conversion-alloying mechanism for advanced lithium ion batteries. However, the sluggish conversion reaction severely degrades the reversible capacity, Coulombic efficiency and rate capability. In this paper, through constructing porous Ni/SnO2 composite electrode composed of homogeneously distributed SnO2 and Ni nanoparticles, the reaction kinetics of SnO2 is greatly enhanced, leading to full conversion reaction, superior cycling stability and improved rate capability. The uniformly distributed Ni nanoparticles provide a fast charge transport pathway for electrochemical reactions, and restrict the direct contact and aggregation of SnO2 nanoparticles during cycling. In the meantime, the void space among the nanoclusters increases the contact area between the electrolyte and active materials, and accommodates the huge volume change during cycling as well. The Ni/SnO2 composite electrode possesses a high reversible capacity of 820.5 mAh g-1 at 1 A g-1 up to 100 cycles. More impressively, large capacity of 841.9, 806.6, and 770.7 mAh g-1 can still be maintained at high current densities of 2, 5, and 10 A g-1 respectively. The results demonstrate that Ni/SnO2 is a high-performance anode for advanced lithium-ion batteries with high specific capacity, excellent rate capability, and cycling stability.