bluuebunny/crossref_metadata_2025_split huggingface dataset:
Investigation of NaxMn0.5Fe0.5O2 Cathode Materials from Low Cost Preparation Routes
Authors: Salamone Matteo , Ruffo Riccardo , Longoni Gianluca , Mari Claudio Maria 
Published: February 2020

The wide use of lithium in rechargeable batteries has made it strategic and expensive and therefore different approaches have been recently investigated to overcome this issue. Even though sodium has higher atomic weight, higher oxidation potential and bigger ionic radius than lithium, it can be a valuable alternative in less weight/volume-sensitive applications because of its wider availability and lower costs. At the present, the most promising sodium systems use a transition metal oxide and hard carbon as positive and negative electrode, respectively. In this configuration, considering the material specific capacity and the discharge profiles, the battery could be reasonably able to display an energy density of about 70-80% of lithium analogous with unexplored power density. However, several polycrystalline compounds show lower diffusivity barrier for Na+ compared to Li+ homologous structures. Among the oxide materials, different phases have been proposed like NaCrO2, NaxCoO2, NaxMnO2, and NaxMn0.5Fe0.5O2showing capacity about 100-150 mAh/g in the potential range from 2.0 to 4.0 V vs. metallic sodium with good kinetic. In particular, the Na0.67[Fe0.5Mn0.5]O2P2 structure has received significant attention due to the presence of the relative inexpensive and environmental friendly Mn and Fe in the structure.
We report here two different low cost methods to prepare Na0.67[Mn0.5Fe0.5]O2 (NMFO); the former route is based on sol gel approach from acetate precursors in methanol while the latter one on the use of cotton as template agent. The suitable chemical precursors as well as the thermal treatment procedures were carefully selected after TGA/DSC analysis of various reaction mixtures. The resulting phases have been structural characterized by XRPD with Rietveld analysis which reveals that a small amount of hematite (< 5%) is present in both samples. The morphological analysis by SEM and TEM confirm the good crystallinity and show the characteristic platelet shape having several mm largeness and few hundred nm thickness. The electrochemical characterization was performed in 3 electrode Swagelock type cell using metallic sodium as both counter and reference electrode and a 1M solution of NaClO4in EC:DMC 1:1 + FEC 2% as electrolyte. The charge discharge profiles show the two characteristic plateau at low (2.3/2.7 V) and high potential (3.6/4.0 V) vs. metallic sodium. The galvanostatic cycling results (see Figure 1, sol gel material) reveals a reversible specific capacity of about 120, 110, and 60 mAh/g at current rates of C/20, C/10, and C/2, respectively.
In conclusion, both low cost methods are able to produce micrometric sized NMFO materials with good electrochemical properties as cathodes in sodium ion battery.
Facile Way to Synthesis of Nanocable-like Electrode Materials for High-Performance of Lithium-Ion Batteries
Authors: Wang Bin , Cheng Jianli , Nie Fude 
Published: February 2020

Recently, One-dimensional (1D) CNT@ metal oxide coaxial nanocomposites with controlled size and chemical composition have attracted particular interests because of their superb lithium storage capability provided by their unique structure.1-3 However, so far these reported synthetic approaches usually involve multiple time-consuming procedures, toxic chemicals, and encounter nonuniform morphology problem.
In this report, we present a simple and green one-pot route to form a new nanostructured CNT@ metal oixdes-C nanocable by using glucose as structure-directing agent and carbon source without any prerequisite for covalent/ non-covalent functionalization of CNTs. Although glucose is often used as a carbon source in hydrothermal reactions,4,5 it is the first time to be used as a structure-directing agent to form CNT@ metal oxides-C nanocable.
This simple and green approach can be used for the fabrication of metal oxide/CNT nanocomposites, including but not limited to CNT@TiO2-C nanocable, CNT@Fe3O4-C nanocable, CNT@SnO2-C nanocable (showing in Figure 1). Due to the synergistic effect of the high electronic conductivity support and the inner CNT/outer carbon buffering matrix, the nanocables show improved lithium storage behavior when used as anode materials. For example, The CNT@TiO2-C nanocables show remarkable rate capability with reversible charge capacity of 210,178 and 127 mAh g-1at 10C, 20C and 50C, respectively (showing in Figure 2), as well as excellent high rate cycling stability with a capacity retention of 87% after 2000 cycles at 50C.
In summary, by using a simple synthesis method and low cost starting materials, it is now possible to prepare sandwiched CNT@ metal oxdies-C nanocables for high performance of LIBs. We anticipate that the one-pot synthesis method proposed in this study will provide more choices for addressing the problems of LIBs. This talk will further describe testing and capabilities of these materials.

Reference

1. M. Sathiya, A. S. Prakash, K. Ramesha, J. M. Tarascon and A. K. Shukla, J Am Chem Soc, 2011, 133, 16291-16299.

2. F. F. Cao, Y. G. Guo and L. J. Wan, Energ Environ Sci, 2011, 4, 1634-1642.

3. A. L. M. Reddy, M. M. Shaijumon, S. R. Gowda and P. M. Ajayan, Nano Lett, 2009, 9, 1002-1006.

4. X. W. Lou, J. S. Chen, P. Chen and L. A. Archer, Chem Mater, 2009, 21, 2868-2874.

5. X. M. Sun and Y. D. Li, Angew Chem Int Edit, 2004, 43, 597-601.
Three-Dimensional Silicon/Carbon Core-Shell Electrode As an Anode Material for Lithium-Ion Battery
Authors: Kim Jung Sub , Kohler Robert , Pfleging Wilhelm , Seifert Hans Jürgen , Byun Dongjin , Jung Hun-Gi , Lee Joong-Kee 
Published: February 2020

The high-performance materials used for lithium ion batteries include Si-based materials which are some of the most promising materials for electrodes in large rechargeable batteries because of their exceptionally high gravimetric capacity (3,572 mAh/g), low redox potential between 0.2 and 0.4 V (vs. Li/Li+) and low reactivity with non-aqueous electrolyte. Practical application of silicon anodes with huge capacity for lithium ion batteries has so far been mainly hindered due to its low electrical conductivity and large volume change (ca. 400 %) generating during the lithiation and delithiation process [1]. Thus, surface engineering for particles (active material design) and modification for electrode structure (electrode design) of silicon are necessary to alleviate these critical limiting factors. The silicon/carbon core-shell particles (Si@C, active material design) were prepared by thermal chemical vapor deposition and subsequent three-dimensional electrode (electrode design) with channel width of 30 µm using laser technique. The electrochemical characteristics of three-dimensional Si@C employed as anode material for lithium-ion batteries were investigated in order to find effects of material and electrode design. The introduction of carbon coating and laser structuring was achieved the enhanced performance of Si anode materials exhibiting high specific capacity (>2,000 mAh/g), good rate capability and stable cycling (>95% over 50 cycles). The morphology of core-shell having 3D channel could minimize the volume expansion by adoption of void space during repeated cycling.
[1] D. Larcher, S. Beattie, M. Morcrette, K. Edström, J.-C. Jumas and J.-M. Tarascon, J. Mater. Chem. , 17, 3759 (2007).
Mesoporous Lithium Titanate-Carbon Composite (Li4Ti5O12-Carbon) with Controlled Microstructure As Anode in Lithium Ion Batteries for Wide Temperature Range
Authors: Li Chi-Ying Vanessa , Ho Ching-Kit , Yung Hoi , Chan Kwong-Yu 
Published: February 2020

The high discharge rate performance of lithium titanate (Li4Ti5O12) is limited by the low electronic conductivity of the material (< 10-11 Sm-1), addition of carbon is one of the effective way in enhancing the rate performance. [1-4]
In this study, carbons with a hollow core and mesoporous shells of controlled dimensions (in terms of diameter of core, thickness of the shell and diameter of the mesopores) were synthesized via silica hard-template method (Fig. 1). Li4Ti5O12-carbon composites were built through impregnation of Li4Ti5O12 into the core-shell carbon (Fig. 2). These Li4Ti5O12-carbon composites demonstrate higher electronic conductivity, and enhanced electrochemical behavior for prolonged cycles at high discharge rate due to increased surface area of the active material, and improved ion transport pathways from possibly the length scale effect.
Cross-section TEM studies have been performed and proved that Li4Ti5O12 particles are impregnated within the mesoporous carbon shell structure. (Fig. 3) This Li4Ti5O12-carbon composite can achieve superb coulobmic efficiency of 98% and 96%, and superior long-cycling life with remarkably high capacity retention of 99% and 85% over 2,000 cycles at 10C (2.2 Ag-1) and 20C (4.4 Ag-1), respectively. Similar electrochemical behavior is observed for low temperature condition.

Acknowledgement

This work was supported by Hong Kong Research Grants Council General Research Fund (HKU 700209P), Strategic Research Theme on Clean Energy, University Development Fund on Initiative on Clean Energy, and Innovation and Technology Fund of the Hong Kong SAR (ITS/076/11).

References

C.K. Ho, H. Yung, M. Zhou, C.Y.V. Li, K.Y. Chan, “Mesoporous Lithium Titanate-Carbon Composite with Controlled Microstructure”, Abstract #1148, 224th ECS Meeting, October 2013, San Francisco, U.S.A.

S.W. Ting, C.Y.V. Li, H. Yung. C.K. Ho and K.Y. Chan, “Structural and Electrochemical Studies of Mesoporous Li4Ti5O12-TiO2 Composite Spheres as Anode Material for Lithium ion Batteries, 222nd ECS Meeting, October 2012, Honolulu, Hawaii, U.S.A.

C.Y.V. Li, S.W. Ting, Z. Yang, W. Zhuang, X. Lu, H. Yung and K.Y. Chan, “Lithium Titanate Prepared from Mesoporous TiO2 Fiber as Anode Material for Lithium Ion Batteries, , 222nd ECS Meeting, October 2012, Honolulu, Hawaii, U.S.A.

X. Zheng, C. Dong, B. Huang, M. Lu, Int. J. Electrochem. Sci., 7 (2012) 9869 – 9880.
Electrodeposited Three-Dimensional Porous Silicon Nanostructure with Excellent Stability and High Rate Performance for Lithium-Ion Batteries
Authors: Suk Jungdon , KIM Do Youb , KIM Dong Wook , Kang Yongku 
Published: February 2020

Recently, rechargeable lithium ion batteries with higher energy/power densities and better rate performance have been widely developed to be used for powering future portable electronic devices and for application to renewable energy storage facilities and in electric vehicles (EVs)[1]. Silicon is one of the most promising anode candidates owing to its extremely high theoretical capacity of 4200 mAh/g (with the formation of the Li4.2Si alloy), which is more than 10 times higher than the capacity of graphitic carbon (372 mAh/g) and other Li alloys.[2] Due to a major volume change (300-400%) of Si during the lithiation/delithiation processes, the resulting pulverization and a loss of electrical connection between the active materials and the electrode framework cause serious irreversible capacity loss and poor cyclability. In order to solve the pulverization issues of Si, we have fabricated 3D porous Si/metal (copper or nickel) film by an electrodeposition method using two types of template; one is a hydrogen gas bubble template and the other is inverse opal template. Compared with chemical vapor deposition or etching method for porous 3D Si anode, electrodepostion method is a simple and low-cost method which is used for large scale operation in industry.[3] Our 3D porous silicon/metal anode with a well-defined configuration for lithium ion batteries consists of interconnected metal film, which not only allows for robustness during the charge and discharge process with the volume expansion but enables the formation of a large area for silicon electrodeposition at a high capacity in lithium ion batteries. The resulting self-supported 3D porous Si/metal electrodes exhibit a high reversible capacity (2824 mAh/g), remarkable cycling stability (1628 mAh/g after 100 cycles) and superior rate capability without any binder or conductive additives. The results using the 3D porous Si/metal anode in our study represent a promising approach for high-performance silicon-based anodes which are compatible with scaled-up manufacturing process for next-generation lithium-ion batteries due to their simple and rapid fabrication process.

[1] J. Maier, Nature Materials, 2005, 4, 805.
[2] B. A. Boukamp, G. C. Lesh, R. A. Huggins, Journal of Electrochemical Society, 1981, 128, 725.
[3] Y. Nishimura, Y. Fukunaka, Electrochimica Acta, 2007, 53, 111.
New Benzimidazole Nitronyl Nitroxides As Electro-Active Compounds for Battery Electrodes
Authors: Akay Sevda , Esat Burak , Fidan Ismail , Hirel Catherine , Frank Natia 
Published: February 2020

Battery systems are energy sources in wide scope of applications such as mobile phones, portable computers, uninterruptible power supplies. Radical bearing organic polymers, also called radical polymers, may be used as cathode- or anode-active materials in batteries. TEMPO (2,2,6,6-Tetramethylpiperidin-1-yl-oxyl) bearing polymers have been synthesized and studied as electrode materials for rechargeable batteries1. In a similar way, benzimidazole nitronyl nitroxides (BNNs) which are nitroxide-containing organic molecules like TEMPO can also be utilized as electro-active materials. Our studies involving synthesis and utilization of these molecules as cathode or anode materials in Li-ion batteries will be presented.
References
1. A Y. Liang , Z. Tao , J.Chen,
Adv. Energy Mater.
2012, 2, 742–769.
A Facile Approach to Prepare Rattle/Hollow-Type α-Fe2O3 Submicron Spheres with a Thin Carbon Layer for High-Performance Lithium Ion Battery Anodes
Authors: Lim Hyung-Seok , Sun Y.-K. , Suh Kyung-Do 
Published: February 2020

Recently, the hollow structures of various transition metal oxide materials (cobalt oxides [1], iron oxides [2], nickel oxides [3]) have received particular attention for use in lithium-ion batteries (LIBs) because they not only have a higher theoretical capacity than commercial graphite (372 mAh g-1), but also possess a large void space that can accommodate huge changes in volume during electrochemical reactions. In our previous report, hollow Fe3O4 microspheres exhibited the improvement of cyclability. Although the hollow Fe3O4 microspheres show remarkable improvement in cycling stability, most still exhibited capacity fading at high current rates due to their poor electrical conductivity. In order to improve cycling performance at high current rates, we have prepared rattle/hollow-type α-Fe2O3 submicron spheres with thin carbon layer through the diffusion of metal ions into the hydrogel template. In this synthetic process, an additional carbon coating process is not necessary such as two-step hydrothermal process and chemical vapour deposition (CVD). In addition, we report a strategic synthesis method to control the internal structures of α-Fe2O3 submicron spheres. Of the two types of samples, the rattle-type α-Fe2O3 submicron spheres have a high surface area (1415 m2 g-1) because α-Fe2O3 nano-grains are formed in polymer networks. During removal process of template particles by heat treatment, because the cross-linked networks surrounding tiny Fe metal precursors act as a barrier to prevent particle growth, the rattle structured α-Fe2O3 submicron spheres consisting of nano-sized grains with a high surface area can be formed. In this process, the thin carbon layer is formed on the inside surface as well as outer surface of the α-Fe2O3 nano-grains, which was generated from a decomposition of the polymer templates. These rattle/hollow α-Fe2O3 submicron spheres with thin carbon layer exhibit excellent cyclability at high current rates (~10C). We demonstrated that the void space and thin carbon layer covering most of the α-Fe2O3 surface acts as buffer layer to accommodate variation in the volume of α-Fe2O3 and improves charge transfer at high current rates.
References
[1] J. Wnag, N. Yang, H. Tang, A. Dong, A. Jin, M. Yang, D. Kisailus, H. Zhao, Z. Tang and D. Wang, Angew. Chem. Int. Ed., 2013, 52, 6417.
[2] H. –S. Lim, B. –Y. Jung, Y. –K. Sun, K. –D. Suh, Electrochimica Acta, 2012, 75, 123.
[3] N. H. Idris, J. Mater. Res., 2011, 26, 860.
A Novel CuO-Carbon/ Ni-Cu-Mn-Spinel Lithium-Ion Battery
Authors: Verrelli Roberta , Sun Y.-K. , Hassoun Jusef 
Published: February 2020

We report here a copper-doped Li0.85Ni0.46Cu0.1Mn1.49O4 high voltage, spinel electrode prepared by an easy, two-step co-precipitation and solid state process. We show that this material adopts an unique morphology characterized by well-developed, crystalline and aggregated micro-particles, that considerably reduces the occurrence of side reactions. This electrode material can operate in a lithium cell at voltages as high as 5.3 V without sign of electrolyte decomposition, delivering a capacity of about 100 mAh g-1 with high retention and high coulombic efficiency over prolonged cycling. By combining Li0.85Ni0.46Cu0.1Mn1.49O4as cathode with a conversion-type, CuO-MCMB anode, a full lithium ion battery exhibiting good performances in terms of voltage (3.4 V), coulombic efficiency (higher than 95%) and stability is obtained.
To the best of our knowledge, such a copper-based battery system is here originally reported. This battery employs sustainable, eco-compatible, low-cost and easily-prepared electrode materials, an additional bonus that makes it particularly suitable for practical exploitation.
A New Free Standing ZnO/MWCNT Nanocomposite Anode Produced By Sol-Gel Spin Coating Method for Li-Ion Batteries
Authors: Köse Hilal , Karaal Seyma , Aydin Ali Osman , Akbulut Hatem 
Published: February 2020

Lithium-ion batteries (LIBs) are one of the most popular types of rechargeable battery for portable electronics, with one of the best energy densities, and also the choice power source for electric and hybrid vehicles [1]. Zinc oxide is an attractive material as a potential substitute for the conventional graphite anode in lithium-ion batteries, because the theoretical capacity of ZnO (978 mAhg-1) has been estimated to be superior to that of graphite (372 mAhg−1) [2]. High capacity anodes such as zinc based usually suffer severe capacity fading, stemming from both the quick aggregation of zinc particles and the huge volume expansion during Li+ insertion/extraction cycles, which cause pulverization of the anodes and electrical detachment of active materials [3]. MWCNT buckypaper substrate is considered as a buffer material to prevent mechanical disintegration of anode material during the battery applications. In this work, ZnO/MWCNT buckypaper nanocomposite films were prepared as free-standing anode materials by sol–gel spin coating method. To the best of our knowledge there is no work to be published by using highly porous MWCNT buckypapers to be infiltrated with ZnO sol by spin coating. It was aimed to accommodate the stresses arisen from the volume increase during charging process by using highly porous MWCNT network that coated with a thin layer of the ZnO. The structural properties and electrochemical performance of free standing ZnO/MWCNT buckypaper composite film anodes of CR2016 type Li-ion batteries were investigated. SEM (Scanning Electron microscopy), EDS (Energy-dispersive X-ray spectroscopy), XRD (X-ray diffraction) analyses and electrochemical performance tests were performed to characterize the nanocomposites. The cells were charged and discharged at 25 °C between fixed voltage limits (2.5 V to 0.2 V) on an MTI model of BST8-MA battery tester.
[1] Y. Wang, F. Su, J.Y. Lee, X.S. Zhao, Chem. Mater., 18, 1347-1353 (2006).
[2] M.O. Guler, T. Cetinkaya, U. Tocoglu, H. Akbulut, Microelectronic Engineering, doi:10.1016/j.mee.2013.12.029 (2014).
[3] X.H. Huang, X.H. Xia, Y.F. Yuan, F. Zhou, Electrochim. Acta, 56, 4960-4965 (2011).
Self-Discharge Phenomena in LiCoPO4 Electrodes
Authors: Brutti Sergio , Manzi Jessica , Vitucci Francesco , Trequattrini Francesco , Paolone Annalisa , Di Lecce Daniele , Panero Stefania 
Published: February 2020

Polyanion-type materials, like lithium iron phosphate, are one of the recent great success in the research field of applied electrochemistry. Within this family, LiFePO4 (LFP) is a now mature material and its properties have been largely optimized thus opening the door to its commercial exploitation as cathode material in lithium-ion cells for power tools. In recent years the attention of the scientific community is focusing the great advantage of the substitution in the LFP lattice of Fe with Mn, Co or Ni. In fact the Mn3+/Mn2+, Co3+/Co2+ and Ni3+/Ni2+ couples show increasing redox potentials, all higher than the Fe3+/Fe2+, thus opening the door to large improvements in the energy performances. Among them LiCoPO4(LCP) is the best compromise: it shows in lithium cells an higher working potential compared to LFP, still within the working limits of the carbonate-based liquid electrolytes. However many fundamental aspects of the LCP properties and reaction mechanisms in lithium cells are not completely understood. Owing to this, large room for improvements in the performances in Li-cells of LCP is expected by assessing the synthesis route, the coatings, the doping/substitution and the electrolyte additives.
The aim of this communication is to present our recent results concerning the study of one of the most detrimental phenomenon observed in the use of LCP in lithium-ion cells: self-discharge.
Upon charge in lithium cells LCP undergoes to the following reversible two step oxidation:
LiCoPO4 → Li0.7CoPO4+0.3Li++0.3e- → CoPO4+ Li+ + e-

At the end of charge, in absence of flowing current, the self-relaxation of the charged LCP electrode is accompanied by a change in the OCV very similar to the discharge curve at constant current. Apparently prolonged OCV relaxation leads to the re-incorporation of lithium ions into the electrode that can be newly electrochemically charged. Self-discharge is a spontaneous phenomenon and has big technological consequences as it limits the use of LCP in commercial electrodes.
Here we discuss the results of our study of LCP self-discharged electrodes by ex-situ synchrotron powder diffraction, synchrotron infrared spectroscopy and transmission electron microscopy. Self-discharge apparently occurs by the following spontaneous reactions in OCV conditions:
CoPO4 + 0.7 Li++electrolyte (reduced form) → Li0.7CoPO4 + electrolyte (oxidized form)
Li0.7CoPO4 + 0.3 Li++electrolyte (reduced form) → LiCoPO4 + electrolyte (oxidized form)
The two self-discharge steps are accompained by accumulation of electrolyte decomposition by-products on the electrode surfaces.