Abstract: The present invention is to provide a lithium titanate (LTO) material for a lithium ion battery. The LTO material has hierarchical micro/nano architecture, and comprises a plurality of micron-sized secondary LTO spheres, and a plurality of pores incorporated with metal formed by a metal dopant. Each of the micron-sized secondary LTO spheres comprises a plurality of nano-sized primary LTO particles. A plurality of the nano-sized primary LTO particles is encapsulated by a non-metal layer formed by a non-metal dopant. The LTO material of the present invention has high electrical conductivity for increasing the capacity at high charging/discharging rates, and energy storage capacity.

Abstract: This invention provides a method for fabricating a flexible porous film. One application of the film is for fabricating a flexible lithium-ion battery. The method comprises depositing at least one electrospun layer on a flexible substrate sheet by electrospinning. The solution used in electrospinning comprises polyvinylidene fluoride (PVDF) and poly(vinylidene fluoride-hexafluoropropylene) (PVdF-HFP) copolymer dispersed in a solvent such that the solution has a polymer viscosity between 300 cP to 1500 cP. A preferred setting of electrospinning process parameters includes a voltage between 20 kV and 50 kV, a feed rate between 3 ml/h and 12 ml/h, and a spinning height between 100 mm and 150 mm. Preferably, PVDF and PVdF-HFP has a weight ratio between 1:1 and 5:1. The solvent may comprise dimethylformamide (DMF) and acetone in a weight ratio between 1:2 and 8:2. The weight of the copolymer is preferable to be 5% to 25% of a total weight of the copolymer and the solvent.

Abstract: The present invention is to tackle the volume expansion problem of the Si anode materials in the application of lithium ion batteries. In the present invention, a simple and green hydrothermal method is use to form loosely packed Si@C core/shell structure. A carbon coating layer is formed on controllably aggregated silicon nanoparticles in a one-step procedure by the hydrothermal carbonization of a carbon-rich precursor.

Abstract: The present invention is to provide a lithium titanate (LTO) material for a lithium ion battery. The LTO material has hierarchical micro/nano architecture, and comprises a plurality of micron-sized secondary LTO spheres, and a plurality of pores incorporated with metal formed by a metal dopant. Each of the micron-sized secondary LTO spheres comprises a plurality of nano-sized primary LTO particles. A plurality of the nano-sized primary LTO particles is encapsulated by a non-metal layer formed by a non-metal dopant. The LTO material of the present invention has high electrical conductivity for increasing the capacity at high charging/discharging rates, and energy storage capacity.