Among diverse cathode materials, conversion reaction-based materials have a high theoretical capacity because of their large number of electrons per metal compound. However, due to the low electrical conductivity, the materials have low reversibility and large polarization. One of the strategies to solve these problems is to make nanocomposite with the active materials and conductive matrix. We develop the nanocomposite to increase the contact area between the nanosize active materials and conductive matrix which can achieve high ion/electron conductivity, high capacity as well as cycling stability.

The development of cathode materials with high energy-density and good rate performance are mainly dependent on precursors’ structure and composition. Many physical features such as density, size distribution, and microstructure of cathode precursors are affected by the synthetic methods. Among various methods, co-precipitation is one of the common reactions to synthesize micro-sized precursors with homogenous size and morphology. We develop various cathode materials by applying this technique to control compositions, particle sizes, and position of transition metals in the particles.

As the demand for electric transportation increases, the importance of lithium-ion batteries with high energy density is emerging. However, since graphite, a commonly used anode active material, has reached its reversible capacity limit, new strategies are needed to create high-capacity anode materials. The method that has been actively studied is using graphite composite anodes by mixing graphite and other materials with high theoretical capacity. The graphite composite anode can be used as a high-capacity anode with improved reversible capacity compared to the existing graphite while maintaining stable charge/discharge characteristics.

Prussian blue (PB) and its analogues (PBA) are a sort of metal-organic framework that consist of metal nodes and cyanide ligands. The basic formula is AxM[Fe(CN)6]y⋅zH2O (A : alkali metal ions, M : transition metals). As their formula shows, they can accommodate various cations with open-frame structure and various transition metals with different compositions can be constructed. By adjusting the type and constituent metals, high-capacity or high-stability materials can be freely synthesized. We investigate the effect of PB or PBAs on energy storage systems by controlling their morphologies.