ABSTRACT
Numerous strategies to advance the performance of the Li ion batteries have been proposed during the past several decades. Recently, the use of nanotechnology has gained much attention to attain this goal, because nanotechnology can provide unexpected battery performance such as the increase of energy density, rate capability, and long-term reliability of the Li ion batteries. Among main components of the Li ion batteries, recent development in nanostructured Li-alloy-based materials as high-capacity anode materials is a good example to show how nanotechnology impacts the performance of the electrode material for next-generation Li ion batteries. Since Dey demonstrated that Li can be electrochemically alloyed with other metals at room temperature in an organic electrolyte (Dey 1971), Li-alloying reactions with metallic or semi-metallic elements and various compounds have been investigated during the past few decades. Most of them are elements from group III (B, Al, Ga, and In), group IV (Si, Ge, Sn, and Pb), and group V (P, As, Sb, and Bi) in the periodic table (Arico et al. 2005; Besenhard et al. 1997; Broussely et al. 1999; Bruce et al. 2008; Cho 2010; Idota et al. 1997; Julien 2003; Larcher et al. 2007; Lee and Cho 2011; Park et al. 2010; Tarascon and Armand 2001; Tirado 2003; Whittingham 2008; Winter and Besenhard 1999; Winter et al. 1998). Among these materials, Si and Sn have been intensively investigated as alternative high-capacity anode materials to replace carbonaceous anode materials for Li ion batteries because of their promising electrochemical properties, such as the large capacities and moderate operating potentials. However, their use for Li ion batteries has been still frustrated by a large irreversible capacity at the ¢rst cycle and poor cycle performance due to a large volume change during cycling. In order to alleviate the mechanical strain generated due to the volume change as the Li ions are inserted to and extracted from Li-alloy-based anode materials, various nanostructured electrode materials including nanosized particles, low-dimensional nanostructures, and nanocomposites have also been intensively explored, and some of them proved to signi¢cantly improve the electrochemical performance of Li-alloy-based anode materials such as excellent capacity retention and dimensional stability over prolonged cycles.
