Electrode materials for lithium secondary batteries prepared by sol-gel methods

Since the commercialization of lithium secondary batteries in the early of 1990s, their development has been rapid. Nowadays, improving the preparation technology and electrochemical performance of their electrode materials is a major focus in research and development of the materials, power sources and chemistry. Sol-gel methods are a promising way to prepare electrode materials due to their evident advantages over traditional methods, for example, homogeneous mixing at the atomic or molecular level, lower synthesis temperature, shorter heating time, better crystallinity, uniform particle distribution and smaller particle size at nanometer level. In this paper, latest progress in the preparation of electrode materials by sol-gel methods is reviewed, including cathodic ones, e.g., lithium cobalt oxides, lithium nickel oxides, spinel and layered lithium manganese oxides, vanadium oxides and ferrous phosphates, and anodic ones, e.g., tin oxides and titanium oxides. Compared with those prepared by traditional solid-state reaction, the structure stability of the prepared electrode materials and the behavior of lithium intercalation and de-intercalation are much improved. As a result, the prepared products provide better electrochemical performance including reversible capacity, cycling behavior and rate capability. In addition, sol-gel methods can be used to prepare new kinds of electrode materials such as nanowires of LiCoO₂ and nanotubes of V₂O₅, which cannot be easily created by the traditional methods. Further development and application of sol-gel methods will bring about new and better electrode materials, meaning a great promotion to lithium secondary batteries.