Preparation And Properties Of Three-dimensional Continuous Porous Titanium Composite Toughened Electrodes

Lithium ion battery(LIB)occupies a large proportion of new energy storage devices.Among the numerous anode materials for lithium ion batteries,TiO₂ electrode materials have the advantages of high lithium insertion voltage,good cycling stability,low price,and no pollution,etc.,making it one of the anode materials for lithium ion batteries with a very promising development prospect.However,due to the low specific capacity,poor mechanical properties,and poor electrical conductivity of single TiO₂ thin film electrode,its application in commercialization is limited to some extent.In this paper,the new flexible TiO₂ electrode prepared by adding titanium mesh and titanium fiber as toughened materials can effectively solve the defects such as poor electrical conductivity and insufficient mechanical properties,and correspondingly improve its specific capacity.In this experiment,the 3D continuous porous titanium composite toughened electrode was successfully prepared by combining non-solvent phase separation(NIPS)and high temperature sintering method with titanium mesh and titanium fiber as self-supporting bodies.The thesis mainly contains all the results as follow:(1)The 3D continuous porous titanium composite toughened electrode precursor(porous titanium toughened plate film)with complete structure and toughness can be prepared by using a titanium powder proportion of 56.8wt.%of cast film,filling scraper forming on the braid titanium network,and then conducting anaerobic sintering at 1000?.(2)TiO₂nanotubes grown on the surface of the precursor by the anodic oxidation method can improve specific surface area.Under the condition of oxidation voltage and time of 40 V-8 h,the 3D continuous porous titanium composite toughened electrode with complete TiO₂nanotube array and high loading capacity can be prepared(3D continuous porous titanium mesh composite toughened electrode).(3)40 V-8 h anodic oxidation in titanium network under the condition of toughened material preparation of electrode has good electrochemical performance,the 100?A cm^-2making electricity given A basically stable current density in 2178.9?A cm^-2,even at high current density(1000?A cm^-2)down specific capacity can be stable in the 1644.3?A cm^-2,keep 75.5%of the initial stage,toughened material preparation to join the high performance anode materials.(4)The 3D continuous porous titanium composite toughened electrode(3D continuous porous titania-fiber composite toughened electrode)with uniform pore size distribution and certain toughness properties was prepared using 1 g doped titanium fiber and 61 wt%titanium powder content.(5)The optimum anodic oxidation parameters of the electrode material prepared with titanium fiber as toughened material were still 40 V-8 h.The specific capacitance was stabilized at 1555.6?Ah cm^-2at the current density of 500?A cm^-2,even at1545.4?Ah cm^-2at A high current density of 1000?A cm^-2,remaining at 72.7%of the initial level(100?A cm^-2).