Preparation And Performance Study Of Porous Titanium Film-TiO₂NTs Composite Electrode

Compared with other types of energy storage devices,lithium-ion battery?LIB?has become one of the most promising energy devices due to their merits of high voltage,high energy-storage density and long cycle life.In recent years,among various Li-ion anodes,TiO₂ has attracted much attention because of its advantages of higher lithium intercalation potential,good cycling stability,low-cost and environmental friendliness.However,with traditional method of coating TiO₂ on copper,the typically weak points,such as low active material loadings and poor conductivity,restrict its application for meeting the large-scaled energy storage demands.Interestingly,the strategy of introducing three-dimentional?3D?current collectors into TiO₂ based electrodes can efficiently migrate these deficiencies.In this work,we prepared a novel 3D Ti membrane through combining nonsolvent induce phase separation?NIPS?and high temperature sintering methods,which possesses uniform pores distribution and controllable membrane thickness.With anodic oxidizing process,the TiO₂ nanotubes?TiO₂NTs?can self grow on the 3D Ti membrane.Remarkably,this freestanding 3D porous Ti/TiO₂ nanotubes?Ti/TiO₂NTs?composite membrane electrode shows high energy density and good rate capacity.The research contents as follows:?1?The raw Ti membrane was obtained by scraping organic cast solution containing 15?m Ti powder,NMP,PVP and PAN?the Ti concentration is wt.58%?.After sintering the as-prepared Ti membrane at 1000? in argon atmosphere,the 3D porous Ti membrane with distributing uniformly pore diameter was prepared,due to the dissociation of PVP and PAN.?2?The Ti/TiO₂NTs composite membrane electrode was synthesized successfully by anodic oxidizing at 30V for 6-10h.It was found that the surface of the 3D Ti showed a clear and regular array of TiO₂ NTs and the 3D porous Ti/TiO₂ nanotubes?Ti/TiO₂NTs?composite electrodes with good mechanical property,which are suitable for freestanding Li-ion anodes.?3?The results suggest that the discharge specific capacity of the electrode is affected by many factors,such as the loading of the active materials and the impedance.Clearly,the impedance of the composite electrode increases with the loading of TiO₂?nanotube length?.Therefore,in the preparation of high specific capacity electrode,it is necessary to comprehensively consider various factors to maximize the energy density of this material.?4?According to the result of electrochemical tests,notablely,the area specific capacitance of TiO₂/Ti-8h can reach up to 2126.7 ?Ah cm^-2 at current density of 100?A cm^-2.Remarkably,the rate capacity keeps 42.45%?902.7??Ah cm^-2)of the initial stage(100 ?A cm^-2)at a high current density of 4000?A cm^-2,as well as high energy density.Finally,the proposed synthetic strategy provides a new way for next-generation storage equipment.