Monodisperse and Inorganically Capped Sn and Sn/SnO₂ Nanocrystals for High-Performance Li-Ion Battery Anodes

Abstract

We report a facile synthesis of highly monodisperse colloidal Sn and Sn/SnO2 nanocrystals with mean sizes tunable over the range 9-23 nm and size distributions below 10%. For testing the utility of Sn/SnO2 nanocrystals as an active anode material in Li-ion batteries, a simple ligand-exchange procedure using inorganic capping ligands was applied to facilitate electronic connectivity within the components of the nanocrystalline electrode. Electrochemical measurements demonstrated that 10 nm Sn/SnO2 nanocrystals enable high Li insertion/removal cycling stability, in striking contrast to commercial 100-150 nm powders of Sn and SnO2. In particular, reversible Li-storage capacities above 700 mA h g(-1) were obtained after 100 cycles of deep charging (0.005-2 V) at a relatively high current of 1000 mA h g(-1).

Metallic Sn‐Based Anode Materials: Application in High‐Performance Lithium‐Ion and Sodium‐Ion Batteries

“…h) Cycling performance comparison of Sn/SnO 2 NCs and commercial samples. Reproduced with permission 33. Copyright 2013, American Chemical Society.…”

“…Further control of the Sn particle size is pursued by researchers. Kravchyk et al33 synthesized monodisperse Sn and Sn/SnO 2 nanocrystals with main sizes tunable from 9 to 23 nm. The performance comparison result showed that the 10 nm Sn/SnO 2 NCs displayed better cycling ability than that of the 20 nm sample and the commercial Sn and SnO 2 nanopowders (Figure 2h).…”

“…Xu et al24 found that significant mechanical damage still occurred even in 10 nm Sn crystals, revealing that size control alone was not sufficient to eradicate the pulverization problem. Moreover, some negative factors of nanocrystallization are considerable issues, such as the high‐cost and complex preparation methods of nano‐Sn,24, 33 large interface contact resistance among nanocrystals,27 low coulombic efficiency caused by the high surface areas and side reactions,32 low compaction density of nanomaterials and the inflammable and explosive characteristics of nanometallic materials. Thereby, size reduction of bare Sn may not be a feasible approach to the practical utilization of Sn anodes.…”

Oxygen-doped carbon host with enhanced bonding and electron attraction abilities for efficient and stable SnO2/carbon composite battery anode

“…. In the first cathodic cycle, a cascade of reduction wave is observed, corresponding to (from higher to lower potential) the reduction of SnO 2 to Sn, the formation of SEI film, and alloying reaction of Sn with Li to form Li x Sn alloy [32]. In the first anodic cycle, the peak at 0.5 V responds to the dealloying process to form Sn, and the peaks at 1.3 and 2.5 V could be assigned to the partial conversion reaction of Sn to SnO 2 accompanied with the decomposition of Li 2 O [25].…”

Surface Chemistry of Colloidal Semiconductor Nanocrystals: Organic, Inorganic, and Hybrid

“…Efficient electronic transport is also required for the use of monodisperse NCs as a medium for storing lithium in rechargeable Li-ion batteries. For example, Kravchyk et al demonstrated that monodisperse Sn NCs exhibit high charge storage capacities of up to 1000 mAh g −1 only after insulating oleylamine/OA capping has been replaced with HS − ions [123], hence enabling fast and reversible reaction Sn + 4.4Li + + 4.4e = SnLi 4.4 .…”