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The present article introduces a strategy for controlling oxidation and reduction reactions within polymer electrolyte membrane (PEM) networks as a means of enhancing storage capacity through the complexation of dissociated lithium cations with multifunctional groups of the polymer network. Specifically, co-polymer networks based on polysulfide (PS) and polyoxide (PO) precursors, photo-cured in the presence of succinonitrile (SCN) and lithium bis(trifluoro methane sulfonyl imide) (LiTFSI) salt, exhibited ionic conductivity on the order of mid 10−4 S/cm at ambient temperature in the 30/35/35 (weight %) composition. Lithium titanate (LTO, Li4Ti5O12) electrode was chosen as an anode (i.e., a potential source of Li ions) against lithium iron phosphate (LFP, LiFePO4) cathode in conjunction with polysulfide-co-polyoxide dual polyelectrolyte networks to control viscosity for 3D printability on conformal surfaces of drone and aeronautic vehicles. It was found that the PS-co-PO dual network-based polymer electrolyte containing SCN plasticizer and LiTFSI salt exhibited extra storage capacity (i.e., specific capacity of 44 mAh/g) with the overall specific capacity of 170 mAh/g (i.e., for the combined LTO electrode and PEM) initially that stabilized at 153 mAh/g after 50th cycles with a reasonable capacity retention of over 90% and Coulombic efficiency of over 99%. Of particular interest is the observation of the improved electrochemical performance of the polysulfide-co-polyoxide electrolyte dual-network relative to that of the polyoxide electrolyte single-network. [ABSTRACT FROM AUTHOR]

The two primary physical methods for identifying lithium titanate, a negative electrode material used commercially, are X-Ray diffraction and Raman spectroscopy. Although there are many publications on this topic, they are focused mainly on chemistry, so there are still some points that require clarification from a physical and methodological point of view. Difference of experimentally observed and theoretically predicted Raman spectra was explained through a combination of experiments and computations. The work comprises experiments and computations to explain why there are different numbers of predicted and observed Raman-active bands. Our low-temperature study and the analysis of thermal shifts during heating led us to conclude that the approach with surplus bands is advantageous and we recommend using major F2g band shifts to estimate the sample heating. [ABSTRACT FROM AUTHOR]

Lithium‐ion batteries with spinel Li4Ti5O12 materials as anode, which can offer fast charge times, high power output, superior safety, and long life, are considered to be a competitive choice for grid‐scale energy storage systems (ESS). Herein, a 10 Ah lithium–titanate battery with lithium cobalt oxide–lithium nickel cobalt manganese oxide dual‐phase cathode is developed and its application in 100 kWh‐level ESS is investigated. The 10 Ah single battery demonstrates a specific capacity of 79 Wh kg−1 with a high‐capacity retention rate of 91.8% after 1000 cycles at 55 °C and >80% capacity retention at 15 Ccell. The 125 kWh ESS shows an energy efficiency of 97.82% and 89.97% at 0.2 and 1.5 CSystem, respectively. Self‐discharge and constant power tests indicate that the battery system is stable, thus suitable for storing intermittent power from renewable sources such as solar and wind. The system's ability of smoothing the fluctuated power is confirmed by coordinating with a wind power system. [ABSTRACT FROM AUTHOR]

The present article introduces a strategy for controlling oxidation and reduction reactions within polymer electrolyte membrane (PEM) networks as a means of enhancing storage capacity through the complexation of dissociated lithium cations with multifunctional groups of the polymer network. Specifically, co-polymer networks based on polysulfide (PS) and polyoxide (PO) precursors, photo-cured in the presence of succinonitrile (SCN) and lithium bis(trifluoro methane sulfonyl imide) (LiTFSI) salt, exhibited ionic conductivity on the order of mid 10−4 S/cm at ambient temperature in the 30/35/35 (weight %) composition. Lithium titanate (LTO, Li4Ti5O12) electrode was chosen as an anode (i.e., a potential source of Li ions) against lithium iron phosphate (LFP, LiFePO4) cathode in conjunction with polysulfide-co-polyoxide dual polyelectrolyte networks to control viscosity for 3D printability on conformal surfaces of drone and aeronautic vehicles. It was found that the PS-co-PO dual network-based polymer electrolyte containing SCN plasticizer and LiTFSI salt exhibited extra storage capacity (i.e., specific capacity of 44 mAh/g) with the overall specific capacity of 170 mAh/g (i.e., for the combined LTO electrode and PEM) initially that stabilized at 153 mAh/g after 50th cycles with a reasonable capacity retention of over 90% and Coulombic efficiency of over 99%. Of particular interest is the observation of the improved electrochemical performance of the polysulfide-co-polyoxide electrolyte dual-network relative to that of the polyoxide electrolyte single-network.

The high energy density and stability of solid‐state lithium batteries (SSBs) have garnered attention. Garnet electrolytes are widely explored in SSBs due to their huge electrochemical potential window, high effective ionic conductivity, and reasonable production cost. However, the electrochemical stability of a metallic lithium anode and a garnet electrolyte pose obstacles to the widespread use of garnet‐based SSBs. To remedy these problems, Li4Ti5O12 (LTO) is added to the metallic lithium anode. With superior wettability on the garnet electrolyte compared to pure metallic Li, Li–LTO is a more desirable electrolyte. Increased wettability between the garnet electrolyte and Li–LTO composite is responsible for the larger absolute value of the interface formation energy found in the first principal density‐functional theory calculation. Since the interface resistance between the Li–LTO composite anodes (25 Ω cm2) and the Li metal (270 Ω cm2) is much lower, Li dendrite development is effectively suppressed. An all‐lithium battery with a Li–LTO anode and a LiFePO4 cathode shows excellent capacity retention of 95% after 450 cycles. This discovery may serve as inspiration for future efforts to create a metallic Li‐containing anode for lithium batteries and other functional LTO‐based composites.

Abstract Significant safety advantages of lithium titanium oxide (LTO) over currently used graphite for lithium-ion batteries have been attracting scientists to develop novel synthetic methods of this anode material in order to combine with another cathode. This study utilizes self-sacrificing cross-linked aqueous templates of gelatin and chitosan polymer to control lithium titanium oxide (LTO) morphology and microstructure. Gelatin and chitosan self-assembled aqueous template containing LTO precursors has been evaporated at 110 °C and then calcined at 750 °C in a muffle furnace to synthesize white color LTO powder. Various techniques such as X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), Energy dispersive x-ray spectroscopy (EDS), Fourier transform infrared spectroscopy (FT-IR), Raman spectroscopy and UV–visible spectroscopy were used to characterize the synthesized LTO powders. Both XRD and EDS spectrum confirm the coating of gelatin and chitosan derived carbon species on the surface of LTO materials. The detailed characterization reveals that increasing the amount of gelatin to the mass ratio of gelatin and chitosan reduced LTO particle sizes. Thus, a size controlled carbon coating LTO preparation strategy have been established via gelatin and chitosan cross-linked aqueous template in controlling the morphology and microstructure of LTO material.

Lithium titanium oxide (Li 2 TiO 3) tritium breeder ceramic plates with nano- and coarse-grain size were fabricated. The preparation methods contained CTAB-modifying precursor, combining dry-pressing with isostatically cold-pressing, and calcinating at optimized sintering temperature in turn. Then their properties were characterized after radiation by 280 keV helium (He+) ion. Extensive characterization analyses were performed to reveal the changes in nano-grained and coarse-grained Li 2 TiO 3 after radiation. They contained glancing angle X-ray diffraction (GIXRD), atomic force microscopy (AFM), electron spin resonance (ESR), and scanning electron microscopy (SEM). The results showed as follows, GIXRD peak position of the nano-grained Li 2 TiO 3 was more stable than the coarse-grained Li 2 TiO 3 after radiation. Nano-grained Li 2 TiO 3 was less rough and swollen than the coarse-grained one after radiation. Nano-grained Li 2 TiO 3 had more excellent structural stability and less defect concentration of Eʹ-center after radiation. As a result, nano-grained Li 2 TiO 3 might have much better radiation tolerance than the coarse-grained one by comparing characterization results. [ABSTRACT FROM AUTHOR]

The degradation of LiNi0.5Mn1.5O4 (LNMO) cathodes were investigated using different cell designs (half cells, full cells cathode-limited, anode-limited and cathode-limited with pre-charge). Half cells based on Li/LNMO show long-cycle stability due to the unlimited source of electrochemically available lithium. Full-cell configurations with Li4Ti5O12/LNMO are limited in their cycling performance and durability. Differential capacity studies during continuous cycling reveal a systematic intensity change of the NiII/III and NiIII/IV redox peaks as a function of the amount of electrochemically available lithium. As a mechanism, it could be clearly stated that the consumption of electrochemically available lithium determines the cycle stability. The decomposition of the active material itself (e.g. loss of Ni and Mn) is not crucial for the capacity loss. Thus, full cells with a pre-charged anode have the best cycling performance because of its high lithium content.

Polymer nanocomposites consisting of materials such as ionic polymers and nano‐ceramic fillers are widely used in high‐power lithium‐polymer batteries because of their high ionic conductivity, good mechanical strength, electrothermal stability, and better compatibility with electrodes. Nanocomposite films of polyvinylidene fluoride (PVDF)/lithium titanium oxide Li4Ti5O12 (LTO) with different volume fractions of LTO nanoparticles (NPs) are prepared via casting method. The DSC thermograms revealed a slight decrease in the melting temperature Tm and a noticeable reduction in the degree of crystallinity with increasing the volume fraction of LTO. This decrease is confirmed by the increment in the relative fraction of β‐phase in the PVDF matrix calculated from both XRD and FTIR. SEM images indicated the growth of porous globular structures in the presence of LTO NPs. Besides, the hydrophilicity of PVDF is improved by incorporating LTO NPs. The dielectric constant ε′(ω), loss ε″(ω), ac conductivity σac(ω), complex impedance Z*(ω), and Nyquist plots of PVDF/LTO nanocomposites are investigated in the temperature range from 303 to 413 K and frequency range from 100 Hz to 1 MHz. The σac(ω) and frequency exponent s are found to obey the correlated barrier hopping model. Values of the frequency exponent s and the charge carriers binding energy Wm for the studied nanocomposite films decrease with rising temperature and LTO addition. Furthermore, dielectric constant ε′(ω), loss ε″(ω), and ac electrical conductivity σac(ω) of films are found to be strongly frequency and temperature dependent. The localized states density N(EF) at the Fermi level increase with increasing temperature and LTO NPs volume fraction, resulting in the Wm decrease and the enhancement of the ac electrical conductivity σac(ω). The impedance spectrum and Nyquist plots provide an insight into the influence of LTO vol% in the resistive and capacitive characteristics of PVDF/LTO films. These results recommend the choice of LTO NPs as dopants to enhance the electrical properties of the PVDF matrix to be used in high‐power lithium‐ion batteries and electronic devices. [ABSTRACT FROM AUTHOR]

This paper introduces the novel anode material which is Li4Ti5O12/Si prepared by gas-stated method, mainly spray-pyrolysis technique. The literature review performed in this paper revealed two main components which can be potentially mixed into the efficient anode material. Silicon (Si) has the highest possible capacity of 4200 mAh g-1 among all commonly used anodes. Due to its ‘zero-strain’ (

In this study, spinel lithium titanate (Li 4 Ti 5 O 12 , LTO) anode materials were synthesized from two titanium sources (P25 TiO 2 , 100% anatase TiO 2) using a spray-drying method and subsequent calcination at various temperatures. The electrochemical performance of both a Li/LTO half cell and a LiNi 0.5 Mn 1.5 O 4 /LTO (LNMO/LTO) full cell were investigated. The electrochemical performance of the LTO material prepared from P25 TiO 2 was superior to that of the LTO prepared from 100% anatase TiO 2. After modification of LTO material with AlPO 4 , the LTO coated with 2 wt% of AlPO 4 (denoted "2%AlPO 4 -LTO") provided the best performances. The specific (delithiation) capacities of the 2%AlPO 4 -LTO anode material was 189.7 mA h g−1 at 0.1C/0.1C, 184.5 mA h g−1 at 1C/1C, 178.8 mA h g−1 at 5C/5C, and 173.1 mA h g−1 at 10C/10C. From long-term cycling stability tests, the specific capacity at the first cycle and the capacity retention after cycling were 185.5 mA h g−1 and 98.06%, respectively, after 200 cycles at 1C/1C and 182.1 mA h g−1 and 99.18%, respectively, after 100 cycles at 1C/10C. For the LNMO/2%AlPO 4 -LTO full cell, the average specific capacity (delithiation) and coulombic efficiency after the first five cycles were 164.8 mA h g−1 and 93.30%, respectively, at 0.1C/0.1C. The specific capacities at higher C-rates were 156.1 mA h g−1 at 0.2C/0.2C, 135.7 mA h g−1 at 1C/1C, 97.5 mA h g−1 at 3C/3C, and 46.5 mA h g−1 at 5C/5C. After twenty-five cycles, the C-rate returned to 1C/1C and the specific capacity, coulombic efficiency, and capacity retention were maintained at 134.1 mA h g−1, 99.17%, and 98.82%, respectively. [ABSTRACT FROM AUTHOR]

We investigated the migration of Li ions at an interface between a LixTi5O12 (LTO) and a solid electrolyte in an all‐solid Li‐ion battery. The optical reflection of LTO changes with variations in the Li content because the band structures of LTO vary with the changes in the Li content. This enables us to observe Li‐ion migration in the interface between the LTO and the solid electrolyte using an optical microscope. To observe the LTO particles optically, they were coated on an indium tin oxide on a glass substrate. Variations in Li migration caused by charging/discharging were clearly observed through the changes in the reflection of the LTO. LTO changed between an insulator Li4Ti5O12 of the spinel structure and a conductor Li7Ti5O12 of the rock‐salt structure according to the changes in the Li content. The spinel LTO has a bandgap energy of approximately 2 eV. When electron–hole pairs were generated, electric strains were produced. Surface force microscopy detected the strains and imaged the distribution of lithiation/delithiation of LTO. Interfacial conduction between a sputtered LTO and Li3PO4 particles was imaged with high spatial resolution. [ABSTRACT FROM AUTHOR]

This study demonstrates the hybridization of Li4Ti5O12 (LTO) with different types of carbon onions synthesized from nanodiamonds. The carbon onions mixed with a Li4Ti5Ox precursor for sol–gel synthesis. These hybrid materials are tested as anodes for both lithium‐ion battery (LIB) and sodium‐ion battery (SIB). Electrochemical characterization for LIB application is carried out using 1 m LiPF6 in a 1:1 (by volume) ethylene carbonate and dimethyl carbonate as the electrolyte. For lithium‐ion intercalation, LTO hybridized with carbon onions from the inert‐gas route achieves an excellent electrochemical performance of 188 mAh g−1 at 10 mA g−1, which maintains 100 mAh g−1 at 1 A g−1 and has a cycling stability of 96% of initial capacity after 400 cycles, thereby outperforming both neat LTO and LTO with onions obtained via vacuum treatment. The performance of the best‐performing hybrid material (LTO with carbon onions from argon annealing) in an SIB is tested, using 1 m NaClO4 in ethylene/dimethyl/fluoroethylene carbonate (19:19:2 by mass) as the electrolyte. A maximum capacity of 102 mAh g−1 for the SIB system is obtained, with a capacity retention of 96% after 500 cycles. [ABSTRACT FROM AUTHOR]

Solution‐based, anionic doping represents a convenient strategy with which to improve upon the conductivity of candidate anode materials such as Li4Ti5O12 (LTO). As such, novel synthetic hydrothermally‐inspired protocols have primarily been devised herein, aimed at the large‐scale production of unique halogen‐doped, micron‐scale, three‐dimensional, hierarchical LTO flower‐like motifs. Although fluorine (F) doping has been explored, the use of chlorine (Cl) dopants is the primary focus here. Several experimental variables, such as dopant amount, lithium hydroxide concentration, and titanium butoxide purity, were probed and perfected. Furthermore, the Cl doping process did not damage the intrinsic LTO morphology. The analysis, based on interpreting a compilation of SEM, XRD, XPS, and TEM‐EDS results, was used to determine an optimized dopant concentration of Cl. Electrochemical tests demonstrated an increased capacity via cycling of 12 % for a Cl‐doped sample as compared with pristine LTO. Moreover, the Cl‐doped LTO sample described in this study exhibited the highest discharge capacity yet reported at an observed rate of 2C for this material at 143mAh g−1. Overall, these data suggest that the Cl dopant likely enhances not only the ion transport capabilities, but also the overall electrical conductivity of our as‐prepared structures. To help explain these favorable findings, theoretical DFT calculations were used to postulate that the electronic conductivity and Li diffusion were likely improved by the presence of increased Ti3+ ion concentration coupled with widening of the Li migration channel. [ABSTRACT FROM AUTHOR]

For implanted medical devices containing rechargeable batteries, maximizing battery lifetime is paramount as surgery is required for battery replacement. In non-life-sustaining applications (e.g., spinal cord stimulators or sacral nerve modulation), these implants may be left unused and unmaintained for extended periods, according to patient preference or in the case of unexpected life events. In this study, we examine the performance of two commercial lithium-ion cells intended for implantable neurostimulators (using lithium titanium oxide (LTO) and graphite as the negative electrode) when subjected to repeated deep overdischarge and to aging at a high state of charge (SOC). The graphite-based cells exhibited significant performance decline and swelling after overdischarge and became unable to store a charge after 42 days at 0 V. In contrast, the LTO-based cells exhibited minimal changes in performance even after 84 days (the length of the study) at 0 V. When subjected to an accelerated aging protocol at 100% SOC, the graphite-based cells were found to age more rapidly than the LTO cells, which exhibited minimal aging over the course of the study period. These results show that practical LTO-based lithium-ion cells are much more tolerant of abuse as a result of neglect and misuse and are worth considering for use in high-value applications where battery replacement is difficult or impossible.

In this work, the potential of Li 1. 8 Na 0. 2 TiO 3 : Mn 4 + for the lifetime-based luminescence thermometry is assessed. The material is prepared by the solid-state reaction of Li 2 CO 3 , Na 2 CO 3 , and nanostructured TiO 2 at 800 °C, and its monoclinic structure (space group C 2/ c) is confirmed by X-ray diffraction analysis. In this host, Mn 4 + provides strong absorption around 330 nm and 500 nm due to 4A 2g → 4T 1g and 4A 2g → 4T 2g electric dipole forbidden and spin-allowed electron transitions, respectively, and emits around 679 nm on account of 2E g → 4A 2g spin forbidden electron transition. Temperature dependences of emission intensity and emission decay are measured over the 10–350 K range. Due to the low value of energy of 4T 2g level (20000 cm−1), the strong emission quenching starts at low-temperatures which favors the use of this material for the luminescence thermometry. It is demonstrated that the quite large value of relative sensitivity (2.27% K−1@330 K) facilitates temperature measurements with temperature resolution better than 0.15 K, and with the excellent repeatability. • Li 1. 8 Na 0. 2 TiO 3 : Mn 4 + was synthesized by the solid-state reaction method in C 2/ c structure. • The material was used as a probe for the lifetime-based luminescence thermometry. • Mn 4 + emits around 679 nm due to of 2E g → 4A 2g spin forbidden electron transition. • The material exhibits a large value of relative sensitivity (2.27% K−1@330 K). • Excellent Mn 4 + emission repeatability with temperature resolution of 0.15 K. [ABSTRACT FROM AUTHOR]

The degradation of LiNi0.5Mn1.5O4 (LNMO) cathodes were investigated using different cell designs (half cells, full cells cathode-limited, anode-limited and cathode-limited with pre-charge). Half cells based on Li/LNMO show long-cycle stability due to the unlimited source of electrochemically available lithium. Full-cell configurations with Li4Ti5O12/LNMO are limited in their cycling performance and durability. Differential capacity studies during continuous cycling reveal a systematic intensity change of the NiII/III and NiIII/IV redox peaks as a function of the amount of electrochemically available lithium. As a mechanism, it could be clearly stated that the consumption of electrochemically available lithium determines the cycle stability. The decomposition of the active material itself (e.g. loss of Ni and Mn) is not crucial for the capacity loss. Thus, full cells with a pre-charged anode have the best cycling performance because of its high lithium content. [ABSTRACT FROM AUTHOR]

LiNi 0.8 Co 0.1 Mn 0.1 O 2 is a promising cathode material for lithium-ion batteries due to its high capacity, high energy density and low cost. However, LiNi 0.8 Co 0.1 Mn 0.1 O 2 suffers from an aggressive side reaction with electrolyte, resulting in poor cycling performance, large polarization and fast voltage degradation. To overcome these drawbacks, we use an acid coprecipitation method to prepare rod-shaped LiNi 0.8 Co 0.1 Mn 0.1 O 2 , and introduce a thin and uniform lithium titanium oxide layer on the surface by a solvothermal method. The 3 mol% lithium titanium oxide-coated LiNi 0.8 Co 0.1 Mn 0.1 O 2 exhibits a much higher capacity retention (88.6%) than the pristine material after 100 cycles, and the polarization and voltage degradation of the Ni-rich cathode are largely alleviated. Furthermore, at an elevated temperature of 65 °C, the capacity retention of lithium titanium oxide–coated LiNi 0.8 Co 0.1 Mn 0.1 O 2 is 81.1% after 50 cycles, which is much higher than that of pristine LiNi 0.8 Co 0.1 Mn 0.1 O 2 (only 52.0%). These results suggest that the surface doping of Ti4+ and the introduction of the lithium titanium oxide layer help to improve the structure stability and mitigate the side reactions on the electrode-electrolyte interface, resulting in good electrochemical performance. • Rod-shape LiNi 0.8 Co 0.1 Mn 0.1 O 2 is synthesized by simple acid co-precipitation. • Uniform and thin layer coating is achieved by solvothermal method. • LiNi 0.8 Co 0.1 Mn 0.1 O 2 with Li-Ti-O coating layer shows improved cycling stability and rate capability. • Polarization and voltage degradation are alleviated by the introduction of Li-Ti-O layer. [ABSTRACT FROM AUTHOR]

Li4Ti5O12 is a promising anode for lithium‐ion batteries due to its zero‐strain properties. However, its low conductivity has greatly affected its rate performance. At the same time, the electrolyte decomposition during cycling also needs to be solved, especially at low cut‐off voltage. Herein, using a high‐throughput two‐step method, we synthesized Zr‐doped LTO modified by mesoporous LiBaF3 nanoparticles for alkali‐ion storage. The doping of Zr can enhance the electronic conductivity and facilitate the rate performance. Meanwhile, the coating of mesoporous LiBaF3 nanoparticles can form a mesoporous surface with large pore size (ca. 3–10 nm), which can benefit the alkali ion diffusion and simultaneously restrain the formation of an excess solid electrolyte interface to a reasonable range. The optimized material is used as an advanced anode for both lithium‐ion and potassium‐ion batteries, and good battery behavior including high‐rate performance and high stability is achieved. [ABSTRACT FROM AUTHOR]

Abstract We report a novel and versatile method of grafting polymers onto lithium titanium oxide (LTO) by dispersion-mediated interfacial polymerization. A myriad of polymers can be grafted by this method, and the hybrid-polymer particles are compatible with all kinds of binders used in lithium-ion batteries. This method is capable of producing thin and homogenous polymer films that are useful for battery applications. A coating of poly(styrene) effectively prevents degradation of the cell after float test without affecting performance at high C rates. Graphical abstract Image 1 Highlights • Versatile method of grafting polymers onto lithium titanium oxide (LTO) is reported. • Hybrid-polymer particles are compatible with all kinds of binders. • Effect of different polymer coatings on cell performances is investigated. • Poly(styrene) coating mitigates degradation of cell after float test. [ABSTRACT FROM AUTHOR]

Abstract A carbon coated commercial lithium titanium oxide (Li 4 Ti 5 O 12 ; LTO) was acoustically mixed with nano-sized AlF 3 and heat treated to form a simultaneous coating layer of carbon and AlF 3 on LTO particles. The surface modified LTO samples were characterized by a variety of means such as X-ray diffraction, Fourier transform infrared spectrometer, high-resolution transmission electron microscope, and inductively coupled plasma mass spectrometry. The results indicate that both carbon and AlF 3 layers exist on the surface of LTO particles and that the distribution of the carbon and AlF 3 differs depending on post heat treatment temperature. The carbon and AlF 3 coating layers formed by optimal post heat treatment at 350 °C significantly improves electrochemical performance, which increases charge capacity by 30% over the pristine LTO after 50 cycles at a high current density of 5C. Thus, LTO with a simultaneous coating layer of carbon and AlF 3 formed by acoustic mixing and post heat treatment shows a potential to further improve commercially-optimized carbon-coated LTO by alleviating its inherently low conductivity. This is an effective way to stabilize the interface between LTO particles and electrolyte, and is a practical approach to promote the wide usage of LTO, one of the most potent anode materials. Graphical abstract Unlabelled Image [ABSTRACT FROM AUTHOR]

In this study, Li4Ti5O12 (LTO) electrodes with different types of water-soluble binders are successfully coated upon aluminum foil. Electrodes containing solely sodium alginate (SA) as a binder or a mixed PVDF/carboxymethyl cellulose (CMC) binder show the most stable performance in 1 M LiPF6 in EC/DMC 1:1 in half cell vs. Li, with respect to cycle stability over 100 cycles at 1 C. The electrodes processed with a mixture of PVDF/SA show considerable fading and slightly worse values for rate capability. Each one of the different binders used is eco-friendly, and the whole processing can be performed without the use of organic solvents. Further advantages covering the whole production and recycling process, as well as safety issues during operation, encourage deeper research in this area.

X-ray photoelectron spectroscopy (XPS) and x-ray-induced Auger electron spectroscopy were used to analyze untreated Li4Ti5O12 powders obtained from Ishihara Sangyo Kaisha, Ltd. and Samsung Fine Chemicals Company, Ltd. X-ray photoelectron and x-ray-induced Auger electron spectra were obtained using incident monochromatic Al Kα radiation at 0.834 01 nm. A survey spectrum together with O 1s, Ti 2p, C 1s, Ti 3s, Li 1s, and Ti 3p are presented. The spectra indicate the principal core level photoelectron and Auger electron signals and show only minor potassium signal. Making use of the O 1s, Li 1s, and Ti 3p lines and neglecting the components related to surface contaminants, XPS quantitative analysis reveals an altered stoichiometry of the air-exposed powder surfaces from Ishihara Sangyo Kaisha, Ltd. and Samsung Fine Chemicals Company, Ltd. of Li4Ti4.7O14.1 and Li4Ti4.3O13.2, respectively. [ABSTRACT FROM AUTHOR]

This paper introduces the novel anode material which is Li4Ti5O12/Si prepared by gasstated method, mainly spray-pyrolysis technique. The literature review performed in this paper revealed two main components which can be potentially mixed into the efficient anode material. Silicon (Si) has the highest possible capacity of 4200 mAh g-1 among all commonly used anodes. Due to its 'zero-strain' (<1% volume change) properties and stable cycling, Li4Ti5O12 (LTO) is considered as a promising anode for lithium ion batteries. Combination of these two anode materials is considered as a promising approach to prepare a high performance composite anode. The precursor solution consisted of homogeneous mixture of lithium nitrate and titanium tetraisopropoxide dissolved in deionized water with equimolar concentration of 0.5 M. The aerosol formation was performed at nitrogen environment and the droplets were carried into the quartz tube reactor at the flowrate of 4 L min-1. The rector temperature was held at 800 °C. The spray-pyrolysis synthesis was performed as one-step operation, excluding the need of calcination of as-prepared powders, and continuous process by the mean of peristaltic pump. The as-prepared powders had wide size distribution from nanometers to microns. The materials obtained had well-crystallized structure with insignificant amount of impurities. The powders were analyzed by the following analytical equipment: 1) the presence of Li4Ti5O12 and Si in the obtained composite was confirmed by X-ray diffraction technique (XRD); 2) The structure and morphology of LTO and Si molecules were observed and studied with Scanning Electron Microscopy (SEM). [ABSTRACT FROM AUTHOR]

Abstract Li 4 Ti 5 O 12 (LTO) with a spinel structure is attractive as a promising anode for lithium-ion batteries due to a high charge/discharge voltage versus Li/Li+ and almost no volumetric expansion with improved cycle performance. In this study, a sea urchin-like nanostructured LTO (F-LTO) was prepared in the presence of F-127 as a surfactant. The morphology and structure of the samples were confirmed using field emission scanning electron microscopy (FE-SEM) and X-ray diffraction (XRD) method. To investigate the electrochemical properties of the samples, charging/discharging analysis was performed for 1000 cycles at a high current density. F-LTO showed an improved capacity retention rate and a high average capacity compared to the LTO sample prepared in the absence of F-127. It was found that, when using the high-rate performance analysis at different charging/discharging current densities, the intercalation of Li+ ion to an electrode might be a crucial factor to reduce capacity and energy density. Due to its porous nanostructure with high specific area, F-LTO showed low polarization and improved kinetic properties, resulting in enhanced LIB performance including high energy density and cycling properties. Graphical abstract Image 1 Highlights • A novel Li 4 Ti 5 O 12 nanostructure was synthesized using F-127 as a surfactant. • F-LTO exhibited a sea urchin-like nanostructure with a high surface area. • F-LTO facilitated an efficient contact between the electrode and electrolyte. • F-LTO showed low polarization and improved kinetic properties. • F-LTO exhibited the high rate cycling properties in LIBs. [ABSTRACT FROM AUTHOR]

Lithium titanium oxide (Li4Ti5O12)-based cells are a very promising battery technology for ultrafast-charge–discharge and long-cycle-life batteries. However, the surface reactivity of lithium titanium oxide in the presence of organic electrolytes continues to be a problem that may cause expansion of pouch cells. In this study, we report on the development of a simple and economical grafting method for forming hybrid polymer–Li4Ti15O12 nanoparticles, which can be successfully applied in lithium-ion batteries. This method utilizes a low-cost and scalable hydrophobic polymer that is applicable in industrial processes. The hybrid materials demonstrated exceptional capability for preventing the degradation of cells in accelerated aging and operating over 150 cycles at 1C and 45 °C. [ABSTRACT FROM AUTHOR]

A feasibility study for the recovery of lithium from salt water with the protonated lithium titanium oxide ion-sieves was carried out in this work. Lithium ions (Li + ) in LiTi 2 O 4 having a similar ion density with H + allow repeated exchanges and regeneration with high selectivity. By Li 7 magic angle spinning solid-state magnetic resonance, it is apparent that chemical structure of lithium in the ion-sieves is not perturbed during the repeated Li + /H + exchange processes. As the dissolution of titanium is negligible (< 0.1%), the secondary contamination during the capture process can be minimized. The ion-sieves exhibit lithium capture capacities of up to 9.5 mg/g during the repeated Li + /H + exchanges with H 0.23 Li 0.77 Ti 2 O 4 /LiTi 2 O 4 for 24 h, and the captured Li + may be recovered in the form of Li 2 CO 3 . Accordingly, the lithium capture method developed in this work could be integrated with current desalination processes for valuable lithium recovery. [ABSTRACT FROM AUTHOR]

Flower-like Li 4 Ti 5 O 12 hollow microspheres consisting of nanosheets are prepared via a hydrothermal process, and subsequently wrapped by graphene through electrostatic interactions. In comparison with pristine Li 4 Ti 5 O 12 , Li 4 Ti 5 O 12 @graphene exhibited higher capacities and improved rate capability in the 0.01–3.0 V or 1.0–3.0 V potential range. Li 4 Ti 5 O 12 @graphene composite shows specific capacity of 272.7 mAh g −1 at 750 mA g −1 after 200 cycles in the potential range from 0.01 to 3.0 V, while the pristine Li 4 Ti 5 O 12 only delivered a discharge capacity of 235.6 mAh g −1 . The improved electrochemical performances of Li 4 Ti 5 O 12 @graphene should be attributed to lower charge-transfer resistances, larger lithium-ion diffusion coefficient and lower activation energy. The electrons transfer at Li 4 Ti 5 O 12 /graphene heterojunction interface, originating from difference in the work function of two composites, reduces the localized work function of the composites, decreases energy required for electrons to escape and consequently results in the improved electrochemical performances. [ABSTRACT FROM AUTHOR]

Li 4-x Mg x Ti 5 O 12 (0 ≦ X ≦ 0.2) anode material was synthesized by a solid-state method using Li 2 CO 3 , MgO and anatase TiO 2 . The effects of Mg element doping on the crystal structure, phase composition, morphology and electrochemical properties of Li 4-x Mg x Ti 5 O 12 were investigated by XRD, SEM and EDX. The electrochemical properties of Li 4-x Mg x Ti 5 O 12 were characterized through Cyclic voltammetry and AC impedance experiments. The results indicated that when x = 0.10, the resultants show better electrochemical performance in higher rates cycle stability and the polarization degree. The initial discharge capacity reaches 122.5 mAh/g at 2 C, and the discharge capacity still remains 119.3 mAh/g after 100 cycles. [ABSTRACT FROM AUTHOR]

Excellent rate performance of Li 4+x Ti 5 O 12 (0 < x < 3, LTO) electrodes results from mixed Li site occupancy and facile Li ion exchange at 8a and 16c sites. In this paper, we reveal that inter-particle connectivity within LTO electrodes affects 8a and 16c site occupancies upon discharge and impacts Li ion diffusion. LTO electrodes of the same primary crystal structure but of different grain boundary structures were prepared and they showed significantly different electrochemical performance. LTO electrodes with a percolated 3D structural network and bridged grain boundaries offered balanced 8a-16c occupancy, Li ion exchange at 8a and 16c sites upon discharge, high ionic conductivities, and good rate performance. While LTO electrodes with isolated clusters of particles showed strong rate dependence of 8a-16c occupancy, a lack of Li ion exchange at 8a and 16c sites, large over-potential, and substantial capacity decay upon fast charging. Bridged grain boundaries in LTO secondary particles facilitate apparent solid-solution process during electrochemical cycling by maintaining Li site exchange and thus enhance the rate performance of LTO electrodes. [ABSTRACT FROM AUTHOR]

Ni-based layered LiNi 0.5 Co 0.2 Mn 0.3 O 2 (NCM) compounds coated with lithium titanium oxide for lithium ion batteries were successfully achieved through a simple solid state synthesis process using TiO 2 powder and CH 3 COOLi. Systematical measurements in structure, morphology and electrochemical properties have been applied. X-ray diffraction patterns showed the existence and conversion of lithium titanium oxide (Li 4 Ti 5 O 12 and Li 7 Ti 5 O 12 are labeled as LTO). A coating layer in the form of LTO could be observed and the thickness was approximately 10 nm with uniform distribution. Similarly, XPS was performed to confirm the existence of LTO. 1.0 wt .% LTO-coated NCM material exhibited higher capacity retentions of 91.0% than that of the bare one (64.3%) after 100 cycles at cutoff voltages of 4.5 V. Meanwhile, the LTO-coated NCM material showed significantly improved thermal stability compared with the pristine sample at an elevated 60 °C. In addition, it has proved that it is effective to enhance the electrochemical performances of electrodes by LTO modification. [ABSTRACT FROM AUTHOR]

Lithium titanates are used in various applications, such as anode materials for lithium intercalation (Li4Ti5O12) or breeding materials in fusion reactors (Li2TiO3). Here, we report the formation of nano-crystalline lithium titanates by a mechanochemical approach and present a deeper insight into their structural characteristics by X-ray diffraction (XRD) and solid-state NMR spectroscopy. The compounds were synthesized in a high-energy planetary ball mill with varying milling parameters and different grinding tools. NaCl type Li2TiO3 (α-Li2TiO3) was formed by dry milling of lithium hydroxide with titania (rutile or anatase) and by a milling induced structure transformation of monoclinic β-Li2TiO3 or spinel type Li4Ti5O12. Heating of mechanochemical prepared α-Li2TiO3 induces a phase transformation to the monoclinic phase similar to hydrothermal reaction products, but a higher thermal stability was observed for the mechanochemical formed product. Microstructure and crystallographic structure were characterized by XRD via Rietveld analysis. Detailed phase analysis shows the formation of the cubic phase from the various educts. A set of two lattice parameters for α-Li2TiO3 was refined, depending on the presence of OH− during the milling process. An average crystallite size of less than 15 nm was observed for the mechanochemical generated products. The local Li environment detected by 6Li NMR revealed Li defects in the form of tetrahedral instead of octahedral site occupation. Subsequent adjustment of the structural model for Rietveld refinement leads to better fits, supporting this interpretation.

Pristine and carbon-coated Li 4 Ti 5 O 12 nanosheets are synthesized by a hydrothermal process, followed by calcination at 750 °C for 10 h. The structural properties of the as-prepared composites are characterized systematically by X-ray diffraction (XRD), Raman spectra, scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HR-TEM) and N 2 adsorption–desorption analysis, respectively. Electrochemical lithium insertion/extraction performances are evaluated by the galvanostatic charge/discharge tests, electrochemical impedance spectroscopy (EIS), and cyclic voltammetry (CV), respectively. In comparison, Li 4 Ti 5 O 12 @C exhibits higher specific capacity, better rate capability and capacity retention than the pristine Li 4 Ti 5 O 12 . Analysis from the electrochemical measurements indicates that the enhanced electrochemical performances Li 4 Ti 5 O 12 @C might be attributed to the shorter Li-ion diffusion distance, lower charge-transfer resistance, better electrode kinetics and lower activation energy as a result of thinner nanosheet and the presence of carbon layer. [ABSTRACT FROM AUTHOR]

In our recent work, we demonstrated that the use of bio-derived rosin as a binder additive could improve the electrochemical performance of lithium titanium oxide (LTO) anodes. As a sequential study, four representative modified rosin-derivatives are used as additives for polyvinylidene difluoride (PVdF) binders in order to further improve the cell performance of LTO electrodes. The rosin derivative modified via simple hydrogenation retains carboxylic acids and is favorable to lithium ion transport when compared to the modified rosins, which loose these functional groups via esterification. The hydrogenated rosin additive increases cyclic capacities, initially by 10 mAh g − 1 and more so at high current charge/discharge rates. [ABSTRACT FROM AUTHOR]

The influence of post-calcination treatment on spinel LiTiO anode material is extensively studied combining with a ball-milling-assisted rheological phase reaction method. The post-calcinated LiTiO shows a well distribution with expanded gaps between particles, which are beneficial for lithium ion mobility. Electrochemical results exhibit that the post-calcinated LiTiO delivers an improved specific capacity and rate capability. A high discharge capacity of 172.9 mAh g and a reversible charge capacity of 171.1 mAh g can be achieved at 1 C rate, which are very close to its theoretical capacity (175 mAh g). Even at the rate of 20 C, the post-calcinated LiTiO still delivers a quite high charge capacity of 124.5 mAh g after 50 cycles, which is much improved over that (43.9 mAh g) of the pure LiTiO without post-calcination treatment. This excellent electrochemical performance should be ascribed to the post-calcination process, which can greatly improve the lithium ion diffusion coefficient and further enhance the electrochemical kinetics significantly. [ABSTRACT FROM AUTHOR]

A new type of non-aqueous redox couple without carbon additives for flow batteries is proposed and the target anolyte chemistry is demonstrated. The so-called “Solid Dispersion Redox Couple” incorporates solid electroactive materials dispersed in organic lithium-ion battery electrolyte as its flowing suspension. In this work, a unique and systematic characterization approach has been used to study the flow battery redox couple in half cell demonstrations relative to a lithium electrode. An electrolyte laden with Li 4 Ti 5 O 12 (LTO) has been characterized in multiple specially designed lithium half cell configurations. The flow battery redox couple described in this report has relatively low viscosity, especially in comparison to other flow batteries with solid active materials. The lack of carbon additive allows characterization of the electrochemical properties of the electroactive material in flow without the complication of conductive additives and unambiguous observation of the electrorheological coupling in these dispersed particle systems. [ABSTRACT FROM AUTHOR]

Highly-crystalline lanthanide (Ln 3+ = Gd 3+ , Y 3+ and La 3+ ) doped and carbon encapsulated Li 4 Ti 5 O 12 (designated as C-Ln-LTO) nanosheets as an anode material for sodium ion batteries (NIBs) are synthesized on large scale via a facile hydrothermal reaction followed by annealing treatment. When evaluated as an anode material for NIBs, the C-Ln-LTO nanosheets exhibit initial discharge specific capacity of 198 mA h g −1 at 0.1C, enhanced rate capability of 141 mA h g −1 at 2C and superior cyclic performance of 122 mA h g −1 at 2C after 150 cycles. The superior rate capability and cyclic performance benefit from the synergistic effect of Ln 3+ doping and carbon encapsulation, which promote electrode reaction kinetics and structural stability during Na + insertion/extraction. Our results reveal the feasibility and universality that the combination of carbon encapsulation and Ln 3+ doping improves electrochemical performance of LTO-based anode materials for rechargeable high-performance NIBs. [ABSTRACT FROM AUTHOR]

The rate capability of a Li 4 Ti 5 O 12 (LTO)-based anode in a lithium ion battery can be easily improved by electron beam (EB) irradiation without the need for complicated synthetic procedures. The electrode prepared with EB-irradiated LTO at a 50 kGy dose has an enhanced rate capability while retaining a discharge capacity of 100 mAh g −1 , even at the 20 C-rate. The effect of EB irradiation on the properties of the anode materials (i.e., LTO, poly(vinylidene fluoride) (PVDF), super P carbon) is examined in detail through systematic experiments. Both LTO and PVDF are affected by EB irradiation and dependent on the exposed electron dose, but super P is affected negligibly. EB irradiation partially reduces LTO with forming Ti x+ (2 < x < 4) which is attributed to the enhanced electrical conductivity. EB irradiation causes dehydrofluorination and cross-linking in PVDF, resulting in the formation of carbon–carbon double bonds. The conjugated structure of PVDF is formed by the further dehydrofluorination during mixing with LTO via ball-milling, and this is accelerated in the presence of EB-PVDF. This conjugated structure enhances the electrical conductivity and is responsible for the improved rate capability. [ABSTRACT FROM AUTHOR]

Highly-crystalline gadolinium doped and carbon-coated ultrathin Li 4 Ti 5 O 12 (LTO) nanosheets (denoted as LTO-Gd-C) as an anode material for Li-ion batteries (LIBs) are synthesized on large scale by controlling the amount of carbon precursor in the topotactic transformation of layered ultrathin Li 1.81 H 0.19 Ti 2 O 5 ·xH 2 O (H-LTO) nanosheets at 700 °C. The characterizations of structure and morphology reveal that the gadolinium doped and carbon-coated ultrathin LTO nanosheets have high crystallinity with a thickness of about 10 nm. Gadolinium doping allows the spinel LTO products to be stabilized, thereby preserving the precursor's sheet morphology and single crystal structure. Carbon encapsulation serves dual functions by restraining crystal growth of the LTO primary nanoparticles in the LTO-Gd-C nanosheets and decreasing the external electron transport resistance. Owing to the synergistic effects rendered by ultrathin nanosheets with high crystallinity, gadolinium doping and carbon coating, the developed ultrathin LTO nanosheets possess excellent specific capacity, cycling performance, and rate capability compared with reference materials, when evaluated as an anode material for lithium ion batteries (LIBs). The simple and effective strategy encompassing nanoscale morphological engineering, surface modification, and doping improves the performance of LTO-based anode materials for high energy density and high power LIBs applied in large scale energy storage. [ABSTRACT FROM AUTHOR]

Electrochemical quartz crystal microbalance (EQCM) measurement is conducted with a Li 4 Ti 5 O 12 (lithium titanium oxide, LTO)-coated quartz crystal electrode in a carbonate electrolyte (ethylene carbonate + dimethyl carbonate; 50: 50 vol%) containing 1 M LiPF 6 . I n-situ monitoring of the mass change during the charge and discharge of the LTO electrode can be achieved quantitatively because of the “zero-strain” property of LTO with Li + insertion and the probably low reactivity between LTO and the electrolyte. The local changes of viscosity and density of the electrolyte contacting the LTO electrode are detected via the resonance resistance of the quartz crystal electrode, suggesting the local concentrations of Li + and counter anion changed significantly during insertion and extraction of Li + in the organic electrolyte. [ABSTRACT FROM AUTHOR]

LiMn 2 O 4 and Li 4 Ti 5 O 12 films were deposited on the lithium-ion conductor of Li 1.3 Al 0.3 Ti 1.7 (PO 4 ) 3 sintered pellet by spray technique. The effect of annealing temperature, annealing time, Li:Ti and Li:Mn molar ratio on the phase and crystallization of the films were investigated with X-ray diffraction. The LiMn 2 O 4 /Li 1.3 Al 0.3 Ti 1.7 (PO 4 ) 3 /Li 4 Ti 5 O 12 thin-film lithium-ion battery using Li 1.3 Al 0.3 Ti 1.7 (PO 4 ) 3 sintered pellet as both electrolyte and substrate was also studied. The results show that the effect of annealing temperature, annealing time, Li:Ti and Li:Mn molar ratio has great effect on the phase and crystallization of Li 4 Ti 5 O 12 and LiMn 2 O 4 films deposited on the Li 1.3 Al 0.3 Ti 1.7 (PO 4 ) 3 sintered pellet. The optimal Li:Ti and Li:Mn molar ratio for the deposition of Li 4 Ti 5 O 12 and LiMn 2 O 4 films on Li 1.3 Al 0.3 Ti 1.7 (PO 4 ) 3 sintered pellet are 7.2:5 and 1.05:2, respectively. The optimal annealing temperature and time for the deposition of LiMn 2 O 4 film on Li 1.3 Al 0.3 Ti 1.7 (PO 4 ) 3 sintered pellet are 650 °C and 10 min. While those for Li 4 Ti 5 O 12 film are 700 °C and 10 min. The LiMn 2 O 4 /Li 1.3 Al 0.3 Ti 1.7 (PO 4 ) 3 /Li 4 Ti 5 O 12 thin-film battery offers a working voltage about 2.25 V and can be easily cycled. [ABSTRACT FROM AUTHOR]

Ethanol is added as a dispersing agent in the slurry preparation step for lithium-ion batteries, in which lithium titanium oxide (Li 4 Ti 5 O 12 , LTO) and conductive carbon (Super P) are dispersed into an aqueous solution of polymer binder (polyacrylic acid). The addition of ethanol suppresses the agglomeration of conductive carbon particles enabling homogeneous mixing of the electrode ingredients in the slurry, which eventually yields a uniform distribution of the LTO and Super P particles in the composite electrodes. Because of the reinforced electrically conductive network formed between the LTO and Super P, the electrode resistance becomes smaller, and thus, a high rate capability is achieved; the capacity of the LTO at 30 C is 73% of that observed at 0.5 C. [ABSTRACT FROM AUTHOR]