Synthesis of composite Li4Ti5O12 nanorods/Sn-AC as anode material for lithium-ion battery (original) (raw)
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International Journal of Technology
Lithium titanate (Li4Ti5O12 or LTO) is a very promising anode material to replace graphite in liion batteries due to its safety and fast-charging ability. However, due to the low theoretical capacity of LTO, a strategy must be developed to overcome this problem. Synthesizing LTO by the combined sol-gel and solid-state method, and the addition of tin powder together with activated carbon, is expected to increase the specific capacity of the anode material. The tin powder compositions in this research were 5wt%, 7.5wt% and 12.5wt%. Further, to investigate the influence of activated carbon, 5wt%, 15wt%, and 25wt% activated carbon were added, while the composition of Sn was kept at 7.5wt%. XRD, SEM and BET surface area measurements was performed to characterize the morphology and structure of the samples. The performance of the battery was analyzed using EIS, CV and CD. The results show that TiO2 rutile was present in the LTO samples, with peak rutile decreasing significantly with the addition of carbon. More disperse particle morphology was obtained by the addition of activated carbon. The LTO/Sn anode material exhibits excellent reversible capacities of 191.1 mAh/g at 12.5wt% tin. Additionally, the LTO/Sn@C has the highest specific-capacity at 270.2 mAh/g, with a composition of 5wt% carbon and 7.5wt% Sn. The results show that LTO/Sn@C is a potential anode material for the future.
Synthesis of LTO Nanorods with AC/Nano-Si Composite as Anode Material for Lithium-ion Batteries
International Journal of Technology, 2018
In this study, the synthesis of lithium titanate (LTO) composite with 3 wt% activated carbons (AC) and 10 wt%, 15 wt%, as well as 20 wt% of nano silicon (nano-Si) are carried out. LTO has zero-strain characteristics and has a long life cycle. However, its capacity is limited, and it has poor electrical conductivity. The addition of nano-Si aims to enhance its capacity, while the AC aims to provide a large specific surface area to increase electrical conductivity. The nanorod templates are made from titanium dioxide (TiO2), which is obtained from titanium (IV) butoxide using the sol-gel method. Nanorod structures are achieved by a hydrothermal process in a 10 M sodium hydroxide (NaOH) solution. However, needle-like structures are also observed, and the Li2TiO3 phase is finally formed. Battery performance is determined by CV, CD, and EIS tests. EIS results show that the highest electrical conductivity is found in LTO only; the CV test results show that the highest specific capacity is found in LTO-AC/15% nano-Si, at 140.7 mAh/g, as well as a charge-discharge (CD) capacity at a current rate of 0.2 to 20 C.
Li4Ti5O12 (LTO) exhibits zero-strain behavior, exceptional cycle stability, low cost, and high safety. However, it is still low in electronic and ionic conductivity. Incorporating Sn into LTO materials can increase electronic conductivity and specific capacity. However, Sn still experiences volumetric expansion during the charging/discharging process. Adding activated carbon (AC) into the LTO/Sn composite can help improve the expansion resistance and electronic conductivity. In this work, the AC was first synthesized from charcoals through the carbon activation process and mixed with LTO precursors through the sol-hydrothermal method followed by mixing with Sn through the mechanochemical process to produce LTO@AC/Sn composites. The Sn content was fixed at 15 wt.%, while the AC contents were varied at 1 wt.%, 3 wt.%, and 5 wt.%. The AC specific surface area is increased by more than 100% compared to the non-activated one. The best effects of AC on grain morphology and distribution we...
Carbon coated Li4Ti5O12 (C-LTO) particles have been synthesized by hydrothermal method and high-temperature calcination process. Nanostructure and carbon-coating has been characterized in detail by Xray diffraction (XRD), high resolution TEM (HR-TEM), selected electron diffraction (SAED), and scanning transmission X-ray microscopy (STXM) combined with X-ray absorption near edge structure (XANES) spectroscopy. The prepared particles are comprised of highly crystalline spinel-type Li4Ti5O12 with the size range of 20-70 nm. HR-TEM imaging and STXM-XANES spectromicrocopy confirmed the amorphous carbon layer uniformly covered on the surface of single LTO particles with optimized content and coating thickness (~5 nm). The electrochemical performance of C-LTO particles as an anode in lithium-ion batteries is evaluated, demonstrating both improved rate capability and cycling performance, which was attributed to the enhanced electron transport/high electrical conductivity and fast lithium-ion insertion/extraction, as a result of uniform and optimized amorphous carbon coating on the C-LTO particles.
Journal of King Saud University - Engineering Sciences, 2020
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IOP Conference Series: Materials Science and Engineering, 2019
Lithium titanate, Li4Ti5O12 (LTO) is a promising candidate as lithium ion battery anode material. In this investigation, LTO/C@ZnO was synthesized with LTO nanorod by hydrothermal method using TiO2 xerogel that prepared by the sol-gel method, lithium hydroxide (LiOH), Activated carbon, and Zinc Oxide (ZnO) nanorod. Three variations of ZnO content addition in weight %, i.e., 4, 7 and 10%, labelled as sample LTO/C@ZnO-4, LTO/C@ZnO-7 and LTO/C@ZnO-10, respectively. The characterizations were made using XRD, FE-SEM, and BET testing. These were performed to observe the effect of ZnO addition on structure, morphology, and surface area of the resulting samples. Result showed that the optimum discharge capacity from each samples was 32.84 mAh/g in LTO/C@ZnO-4 with the crystallite size of 11.86 nm and the surface area of 348.736 m2/g. In cyclic voltammetry testing, it shows a shift in reaction voltage and reduction in capacity that caused by the addition of C@ZnO and the lack of Li4Ti5O12 th...
Nanocomposite particles of amorphous carbon-Li4Ti5O12 (C-LTO) and carbon nanotube-Li4Ti5O12 (CNT-LTO) were synthesized by solvothermal method and subsequent high-temperature calcination. X-ray diffraction (XRD), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HR-TEM), and selected area electron diffraction (SAED) were applied to characterize the phase structure, particle morphology, and the coating structure. XRD analysis, TEM micrographs, HR-TEM images and SAED analysis revealed that both LTO particles exhibited a welldeveloped spinel nanocrystal structure with average sizes between 20-70 nm. The C-LTO particles exhibited roughly spherical shape coated by an amorphous carbon layer up to 10 nm in thickness. The CNT-LTO samples showed uniform square nanocrystals with edge length around 20 nm and nanoscale graphitic layers covering the surface, revealing the carbon nanotubes interconnection networks among the particle assemblies. Electrochemical studies of lithium insertion/extraction performance are evaluated by the galvanostatic charge/discharge tests, cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). Both LTO particles showed the superior initial discharge capacity of more than 200 mAh/g at 1/10C rate. The irreversible capacity of the C-LTO particles at more cycles was due to large polarization resulted from excessive carbon and possible residual precursors. The CNT-LTO particles show larger reversible capacity and enhanced electrochemical Li+ insertion/extraction kinetics at different cycling rates. The comparative structural and electrochemical analyses demonstrated that both nanoscale graphitic covering layers and the CNT interconnection networks increase the electronic conductivity and improve the kinetics rates of lithium insertion/extraction in the CNT-LTO particles.
IOP Conference Series: Earth and Environmental Science, 2018
Li4Ti5O12 (lithium titanate) were synthesized by sol-gel and hydrothermal method with LiOH as lithium ion source. Li4Ti5O12/Sn composites anode were preparared by ball mill method with three of Sn variation. X-ray diffraction shows spinel, TiO2, and Sn phases with anatase and rutile residue. The lowest electrolyte resistance obtained at the highest Sn value. The specific capacity of battery can be increased from addition of Sn by up to 258.6 mAh/g. Alloying and dealloying reaction of LixSn accomodate the increased specific capacity from charge/discharge. However, Thevolume expansion from LixSn leads to loss of capacity when the C rate increases. The efficient capacity at low and high charge-discharge rate obtained at the highest value of added Sn.
Carbon coated Li 4 Ti 5 O 12 (C-LTO) particles have been synthesized by hydrothermal method and high-temperature calcination process. Nanostructure and carbon-coating has been characterized in detail by Xray diffraction (XRD), high resolution TEM (HR-TEM), selected electron diffraction (SAED), and scanning transmission X-ray microscopy (STXM) combined with X-ray absorption near edge structure (XANES) spectroscopy. The prepared particles are comprised of highly crystalline spinel-type Li 4 Ti 5 O 12 with the size range of 20-70 nm. HR-TEM imaging and STXM-XANES spectromicrocopy confirmed the amorphous carbon layer uniformly covered on the surface of single LTO particles with optimized content and coating thickness (~5 nm). The electrochemical performance of C-LTO particles as an anode in lithium-ion batteries is evaluated, demonstrating both improved rate capability and cycling performance, which was attributed to the enhanced electron transport/high electrical conductivity and fast lithium-ion insertion/extraction, as a result of uniform and optimized amorphous carbon coating on the C-LTO particles.