Guo Yuguo

SnO 2 hollow spheres: Polymer bead-templated hydrothermal synthesis and their electrochemical properties for lithium storage

SnO2 hollow spheres have been synthesized via a facile hydrothermal method using sulfonated polystyrene beads as a template followed by a calcination process in air. X-ray diffraction, scanning electron microscopy, and transmission electron microscopy show that the as-obtained SnO2 hollow spheres have a wall thickness of about 50 nm, and consist of nanosized SnO2 particles with a mean diameter of about 15 nm. Electrochemical measurements indicate that the SnO2 hollow spheres exhibit improved electrochemical performance in terms of specific capacity and rate capability in comparison with commercial SnO2 when used as anode materials for lithium-ion batteries. The enhanced performance may be attributed to the spherical and hollow structure, as well as the building blocks of SnO2 nanoparticles.

Electrode materials for lithium secondary batteries with high energy densities

Lithium-ion battery is a widely-used secondary battery with high energy density. However, with a fast development in its field of application, an urgent requirement is raised in the further improving its energy density. This article summarizes the recent research progressions in the cathode and anode materials of lithium-ion batteries with high energy densities as well as some novel lithium secondary batteries based on lithium metal, highlights the selections of cathode and anode materials with high capacities, the designs of micro-nano structures of them, and the strategies toward surface coating and synthesis of these materials with some recent works made in this field by our group. This review also gives a discussion on the future development directions of several lithium metal secondary batteries with high energy densities such as lithium-sulfur battery and lithium-air battery.

3D graphene-based electrode materials foradvanced electrochemical energy storage

Designing specific structured electrode materials is essential for efficient electrochemical energy storage. Graphene owns unique 2D structure and possesses excellent electrical conductivity, ultrahigh specific surface areas, as well as colloidal self-assembling behavior, which make it an ideal candidate for constructing hybrid electrode materials with remarkably enhanced electrochemical performances. This article reviews the recent research progress made on various 3D graphene-based electrode materials and their applications in electrochemical energy storage such as Li-ion and Li-S batteries. Based on the recent works made by our group, we highlight the principles of designing graphene-based materials, and discuss various advanced structures of graphene-based electrodes. Furthermore, future research directions for the development of novel and more efficient graphene-based electrode materials are proposed.