Tianhou Zhang

Effect of morphology and texture on electrochemical properties of graphite anodes

Abstract Three different natural graphite powders (MPG, SPG and HPG) were used to make anode films of lithium-ion batteries by rolling technique. It was found that particle size and particle distribution of graphite, as well as particle orientation in the foil, show great influence on the electrochemical performance of graphite foil anodes. Different X-ray experiments were performed to study the mosaic distributions and coherence lengths of graphite crystallites. This study of the morphology and texture characteristics of anode foils reveals results that pertain to the understanding of electrochemical performance of cells.

Engineered Si Sandwich Electrode: Si Nanoparticles/Graphite Sheet Hybrid on Ni Foam for Next-Generation High-Performance Lithium-Ion Batteries

Si-based electrodes for lithium ion batteries typically exhibit high specific capacity but poor cycling performance. A possible strategy to improve the cycling performance is to design a novel electrode nanostructure. Here we report the design and fabrication of Ni/Si-nanoparticles/graphite clothing hybrid electrodes with a sandwich structure. An efficient dip-coating of Si-NPs combined with carbon deposition was adopted to synthesize the unique architecture, where the Si-NPs are sandwiched between the Ni matrix and the graphite clothing. This material architecture offers many critical features that are desirable for high-performance Si-based electrodes, including efficient ion diffusion, high conductivity, and structure durability, thus ensuring the electrode with outstanding electrochemical performance (reversible capacity of 1800 mA h g(-1) at 2 A g(-1) after 500 cycles). In addition, the hybrid anode does not require any polymeric binder and conductive additives and holds great potential for application in Li-ion batteries.

Electrochemical characteristics of Li4 − xCuxTi5O12 used as anode material for lithium-ion batteries

Cu-doped Li4Ti5O12 (Li4 − xCuxTi5O12) materials were synthesized by solid-state method. Cu-doping does not change the crystal structure of Li4Ti5O12 material but increases its lattice constant. The particle size of Li4 − xCuxTi5O12 powders decreases with increasing Cu-doping level. Cu-doping does not change the specific capacity at low current density, but can improve the cycling stability and the rate capability of Li4Ti5O12 significantly. This is mainly attributed to the enhanced electronic and ionic conductivity and the decreased charge transfer resistance, caused by the increased specific surface area of active Li4 − xCuxTi5O12 powders. The Li3.8Cu0.2Ti5O12 anode material exhibits the best cycling stability and rate capability.

Electrochemical characteristics of Li4 − x Cu x Ti5O12 used as anode material for lithium-ion batteries

Cu-doped Li4Ti5O12 (Li4 − xCuxTi5O12) materials were synthesized by solid-state method. Cu-doping does not change the crystal structure of Li4Ti5O12 material but increases its lattice constant. The particle size of Li4 − xCuxTi5O12 powders decreases with increasing Cu-doping level. Cu-doping does not change the specific capacity at low current density, but can improve the cycling stability and the rate capability of Li4Ti5O12 significantly. This is mainly attributed to the enhanced electronic and ionic conductivity and the decreased charge transfer resistance, caused by the increased specific surface area of active Li4 − xCuxTi5O12 powders. The Li3.8Cu0.2Ti5O12 anode material exhibits the best cycling stability and rate capability.

Electrochemical characteristics of Li 4 − x Cu x Ti 5 O 12 used as anode material for lithium-ion batteries

Cu-doped Li4Ti5O12 (Li4 − xCuxTi5O12) materials were synthesized by solid-state method. Cu-doping does not change the crystal structure of Li4Ti5O12 material but increases its lattice constant. The particle size of Li4 − xCuxTi5O12 powders decreases with increasing Cu-doping level. Cu-doping does not change the specific capacity at low current density, but can improve the cycling stability and the rate capability of Li4Ti5O12 significantly. This is mainly attributed to the enhanced electronic and ionic conductivity and the decreased charge transfer resistance, caused by the increased specific surface area of active Li4 − xCuxTi5O12 powders. The Li3.8Cu0.2Ti5O12 anode material exhibits the best cycling stability and rate capability.