Three‐Dimensional Porous TiNb₂O₇/CNT‐KB Composite Microspheres as Lithium‐Ion Battery Anode Material

Abstract

Nano‐TiNb2O7/multiwalled carbon nanotube and ketjen black (TiNb2O7/CNT‐KB) composite microspheres with porous three‐dimensional (3D) hierarchical heterostructure are fabricated by spray drying and solvothermal method. This composite material exhibits a high reversible charge specific capacity of 327.8 mAh g−1 at the current rate of 0.1 C and 151.1 mAh g−1 at 20 C rate. When it is cycled at a high current rate of 5 C for 1000 cycles, the charge capacity is dropped from the maximum value of 220.8 mAh g−1 (6th cycle) to the end value of 145.4 mAh g−1, with capacity retention of 65.9 %. The TiNb2O7/CNT‐KB composite material demonstrates much superior electrochemical performance over the bare TiNb2O7 material, and this result should be attributed to its particular porous 3D hierarchical structure, which possesses enhanced electrical conductivity as well as the ability for accommodating volume change and preventing particle aggregation of the electrode active material during the discharge and charge cycles.

Recent Advances in Titanium Niobium Oxide Anodes for High-Power Lithium-Ion Batteries

“…Carbon-Based Composites. Advanced carbonaceous materials, such as carbon nanofibers (CNFs), 74 carbon nanotubes (CNTs), 26,79 ketjen black (KB), 26 graphene, 78 bacterial cellulose carbon (BCC), 24 activated carbon cloth (ACC), 80 carbon nanosheets (CNSs), 66 and heteroatom-doped amorphous carbon from polymer pyrolysis, 81,82 are common materials to improve the cycling stability and rate capability of TNO composites. Carbon can not only increase the electronic conductivity of TNO materials but can also reduce TNO and form oxygen vacancies, further increasing the ionic conductivity of TNO materials.…”

“…24,25 In addition, the electronic conductivity of TNO can also be improved by designing carbons utilizing other conductive materials. 26,27 All of these strategies are beneficial to further increase the (de)lithiation ability of TNO anodes at high current densities.…”

TiNb 2 O 7 microsphere anchored by polydopamine‐modified graphene oxide as a superior anode material in lithium‐ion batteries

“…A strong insulating property results in a severe capacity drop in the fast charging/discharging related to the rate performance of the anode electrode . To enhance the conductivity of TNO, a carbon composite, which has a simple preparation process, has been considered for the modification of TNO . As a suitable carbonaceous material, 2D graphene, which has high surface area and electrical conductivity, has been attempted to be introduced for improving the electric/ionic conductivity of TNO.…”

Three‐Dimensional Electrodes for Oxygen Electrocatalysis

“…According to the advantages of solvothermal reaction, great efforts have been achieved in designing 3D structured materials. [39,40] 3D materials derived from other dimensions have attracted wide attention owing to their distinct structural properties, which would adequately take advantages of their original structure. Typical for 2D graphene, a single-atom-thick hexagonally arrayed sp2 carbon bonded sheet, features unique properties, especially ultrahigh specific surface area and superior electrical conductivity.…”