C-LFP-multi-walled carbon nanotubes composite cathode materials synthesized by solid-state reaction for lithium ion batteries.

Multi-walled carbon nanotubes (MWNT) was utilized as a conductive additive to enhance the capacity and rate capability of carbon coated LiFePO4 (C-LFP). Composites of C-LFP with MWNT (C-LFP-MWNT) were prepared by blending MWNT at different stages of C-LFP synthesis. The pre-blending (PrB) of MWNT (5, 10, 15 wt%) with LFP precursor (PrB-C-LFP-MWNT) before calcination in a reducing environment (5 vol% H2 in N2) at 750 degrees C, produced phase pure crystalline LFP with a reduction in particle size as increase in MWNT content. This was contrasted with post-blending (PoB) of MWNT with as-synthesized C-LFP (PoB-C-LFP-MWNT), which gave inferior electrochemical performances. The PrB-C-LFP-MWNT (10 wt%) composite showed better cycle stability, higher rate capability, and faster Li diffusion characteristics than PoB-C-LFP-MWNT.

SnO2/graphene composites with self-assembled alternating oxide and amine layers for high Li-storage and excellent stability.

An alternating stack (SG/GN) consisting of SnO2-functionalized graphene oxide (SG) and amine-functionalized GO (GN) is prepared in solution. The thermally reduced SG/GN (r(SG/GN)) with decreased micro-mesopores and completely eliminated macropores, results in a high reversible capacity and excellent capacity retention (872 mA h g⁻¹ after 200 cycles at 100 mA g⁻¹) when compared to a composite without GN.

TiO2-grafted multi-walled carbon nanotubes for dye-sensitized solar cells.

Dye-Sensitized Solar Cells (DSSCs) comprised of TiO2 porous films with multi-walled carbon nanotubes (MWNT) were prepared at low temperature (150 degrees C). MWNT were incorporated to facilitate the fast electron transport resulting from metallic properties of carbon nanotubes. In order to enhance the effect of MWNT incorporation, TiO2-grafted MWNT (TiO2-MWNT) was synthesized which can increase the electron transport rate further due to proximity of TiO2 to MWNT The presence of TiO2 nanoparticles on the surface of MWNT was confirmed by electron microscopy and energy dispersive X-ray spectroscopy. As in the DSSCs prepared through high temperature sintering of photoanodes, the maximum content of MWNT incorporated into TiO2 was limited to 0.01 wt% relative to TiO2. TiO2 photoanodes including TiO2-grafted MWNT (TiO2-MWNT/P25) enhanced the cell efficiencies by ca. 28% and 14%, relative to TiO2 photoanodes without and with MWNT respectively, reaching the efficiency of 5.0%. Electrochemical impedance spectroscopy (EIS) was utilized to examine the effect of incorporation of TiO2 nanoparticles grafted to MWNT on the cell performance.