bluuebunny/crossref_metadata_2025_split huggingface dataset:
Composite Polymer Electrolytes for Lithium Ion Batteries
Authors: Fan Li-Zhen , Wang Qiujun 
Published: February 2020

Polymer electrolytes are expected to be the alternative electrolytes to satisfy the needs for power storage device because of several important factors, such as high ionic conductivities, reliable safety, easy fabrication, appropriate mechanical properties along with important technological issues related to electrochemical stability. Solid polymer electrolytes prepared by dissolving the salt into the polymer framework are still found to present low ionic conductivities at ambient temperature and dependence of temperature. The ionic conductivities can be enhanced by dissolving polymer matrices and lithium salts in organic solvents. However, liquid electrolytes will deteriorate mechanical properties. Here we have prepared a series of polymer electrolytes with excellent thermostability,well mechanical property, wide electrochemical window and high ionic conductivity, including trimethylolpropane trimethylacrylate (TMPTMA) based, triethylene glycol diacetate-2-propenoic acid butyl ester (TEGDA-BA) based, polyimide (PI) based and polyacrylonitrile (PAN) based polymer electrolytes using in situ thermal polymerization or polymer casting method [1-8]. The as prepared polymer electrolytes exhibit high ionic conductivities, electrochemical stability and excellent charge/discharge cycling performance. The excellent properties of polymer electrolytes make them significant potential materials for next generation lithium ion batteries.
References
[1]. Q.J. Wang, W.L. Song, L.Z. Fan, Q. Shi. J. power sources, 2015, 295: 139-148.
[2]. Q.J. Wang, W.L. Song, L.Z. Fan, Y. Song. J. Membrane Sci., 2015, 492: 490-496.
[3]. Q.J. Wang, W.L. Song, L.Z. Fan, Y. Song. J. Membrane Sci., 2015, 486: 21-28.
[4]. Q.J. Wang, W.L. Song, L.Z. Fan, Q. Shi. J. power sources, 2015, 279: 405-412.
[5]. Q.J. Wang, Z.X. Jian, W.L. Song, S.C. Zhang, L.Z. Fan. Electrochim. Acta, 2014, 149 (12): 176-185.
[6]. Q.J. Wang, W.L. Song, L.N. Wang, Y. Song, Q. Shi, L.Z. Fan. Electrochim. Acta, 2014, 132: 538–544.
[7]. H.H. Fan, H.X. Li, L.Z. Fan, Q. Shi. J. power sources, 2014, 249: 392-396.
[8]. D. Zhou, L.Z. Fan, H.H. Fan, Q. Shi. Electrochim. Acta, 2013, 89: 334-338.
Processing of Aluminum-Doped Lithium Lanthanum Zirconate Garnet-Type Solid Electrolyte Materials
Authors: Fergus Jeffrey , Zhang Xingxing 
Published: February 2020

Lithium lanthanum zirconate (LLZO) with the garnet crystal structure has high lithium ion conductivity and good electrochemical stability, so it is an attractive material for use as the solid electrolyte in lithium ion batteries. One of the challenges in the application of LLZO is processing the material to obtain the desired composition, crystal structure and morphology. In this paper, results on processing of LLZO materials for use in single-phase and composite solid electrolyte materials are presented.
Characteristics of Ionic Liquid/Li-Ion Conducting Hybrid Electrolytes for Graphene-Based Lithium-Ion Capacitors
Authors: Liu Mengxin , Yao Zhuo , Huang Hong 
Published: February 2020

Lithium-ion capacitor (LICs), a novel electrochemical energy storage class combined the advantages of lithium-ion batteries and supercapacitor, are attractive for high energy densities, high power densities, and long cycle life. A typical LIC is made up of a Li-ion battery (LIB) anode, an electrochemical double-layer capacitor (EDLC) cathode, and the common Li-ion electrolyte. Graphene-based nanomaterials have been extensively studied as the electrodes for Li-ion or charge storage in LIBs and EDLCs, respectively. Recently, we have developed reduced graphene oxide (rGO) in composite with MnOx with reversible lithium storage capacity of 900 mA/h. Meanwhile, we have obtained charge storage capacitance up to 150F/g using rGO electrode with an ionic liquid (IL) electrolyte. In this work, we will report our studies on the conducting characteristics of the IL/Li-ion hybrid electrolyte and their compositional impacts on both Li-ion and charge storage in the graphene-based nanocomposites towards high-performance LICs operable in a broad temperature range.
The novel electrolyte series are a mixture of representative IL, e.g. EmimBF4, C8minBF4, C8mimPF6, and the common Li-ion electrolyte, e.g. 1M LiPF6-EC-DEC or 1M LiBF4-EC-DEC, with various preset volume ratios. The ionic conductivities of the hybrid electrolyte series were determined at temperatures from 25oC to 80oC, from which conduction activation energies were calculated. Further, the influences of the hybrid electrolyte composition on the ionic conductivity, activation energy, stability window, Li-ion and charge storage in the graphene-based nanocomposites were systematically studied.
Results showed that ionic conductivities of the hybrid electrolytes increased in general with the addition of Li-ion electrolyte and the activation energies of the ionic conductance increased with the addition of IL. It is interesting to observe a secondary maxima point at around 1:1 volume ratio (IL: Li-ion electrolyte) and higher ionic conductivities of such hybrid electrolyte than that of the neat Li-ion electrolyte above 65oC. The hybrid electrolyte remains relatively stable up to 6V starting from the second cycle after the occurrence of the irreversible reactions corresponding to IL partial decomposition and SEI formation in the first charge/discharge cycle. The novel LIC consisting of the hybrid Li-conducting/IL electrolyte, rGO-MnOx anode, rGO cathode, is anticipated to have a high deliverable energy densities both gravimetrically and volumetricallyand operable in a broad temperature range.
Garnet-Based Electrolytes for All-Solid-State Lithium Batteries
Authors: Li Yiqiu , Zhao Ning , Du Fuming , Chen Cheng , Sun Jiyang , Guo Xiangxin 
Published: February 2020

The lithium garnet has been considered as one of promising solid electrolytes for all solid state rechargeable lithium batteries. Under such circumstance, the Li7La3Zr2O12 (LLZO)-based powders and ceramics have been extensively studied in our lab. By elemental doping, liquid-phase sintering, atmosphere sintering, hot-pressing sintering technique and their combination, high-dense LLZO-based ceramics were obtained, showing the relative density above 99% and the ionic conductivity above 10-
3 S/cm at room temperature.
Based on these powders and dense ceramics, the solid electrolytes in form of hybrid membrane and thin plate were fabricated and used for the all solid state Li-ion and Li-air batteries. The batteries with LiFePO4 or Li(NMC)O2–based cathodes, the LLZO-based electrolytes and Li anodes exhibit good capacity and cycle performance. The Li-air batteries with the porous carbon-based air cathodes, the thin-plate electrolytes and Li anodes work for many cycles under ambient air, especially at elevated temperatures. In the presentation, the scientific and technical details for these batteries will be given. The fundamental issues and promising potential for application will be discussed.
High-Performance Anodes for Lithium-Ion Batteries Based on Nano-Porous Amorphous Silica
Authors: Vullum-Bruer Fride , Hasanuzzaman Muhammad 
Published: February 2020

The high theoretical capacity and low discharge potential of silica (SiO2) draw major interest these days as a serious competitor to Si-based anodes. The drastic volume expansion of Si during cycling leads to capacity fading and pulverization and thus requires advanced treatment to make it a viable electrode in Li-ion batteries1-4. Abundantly available diatomaceous earth was explored as an anode which can substitute the existing graphite based anode, providing better electrochemical performance in terms of capacity, cyclability and stability.
As silica is an insulator, it is necessary to provide a conductive coating on the particles. Various amounts of corn-starch was added, followed by heat treatment in Ar atmosphere, to form a thin continuous conductive layer of carbon on the particles. Also, conventional binders are not compatible with Si or silica-based materials, hence other types of binders and binder additive must explored. Here we have used a naturally grown algae-based aqueous binder to prepare the electrodes, which is compatible with the diatomaceous earth and gives it increased stability during lithiation and de-lithiation. Specific discharge capacities of these materials have shown values of 600-800 mAhg-1, which is more than twice the value of the existing graphite based anodes.
Upon extended cycling the reversible capacity, for uncoated as well as coated silica, starts to increase from approximately the forth cycle due to chemical reactions causing a Si phase to form. The porous morphology and natural nano-structure of the diatomaceous earth anode can accommodate the volume expansion and preserve the solid electrolyte interface. The high reversible capacity, good cycle performance and simple processing of these electrodes make the diatomaceous earth a potential environmentally friendly anode material for lithium-ion batteries.
1. Favors, Z., et al. (2014). Sci. Rep. 4.
2. Yan, N., et al. (2013). Sci. Rep. 3.
3. Liu, X., et al. (2014). Nano Energy 4.
4. Epur, R., et al. (2012). Materials Science and Engineering: B 177(14).
Nickel Hexacyanoferrate-Modified LiFePO4 Cathodes with High-Rate and High-Pulse Current Charge-Discharge Capabilities
Authors: Chiu Kuo-Feng , Leu Hoang-Jyh , Su Shih-Hsuan , Chao Kuan-Yu 
Published: February 2020

Nickel hexacyanoferrate (Prussian blue analogous, PBA) was synthesized by Reverse Micelle Method and was coated on LiFePO4 cathodes to improve the performances of high rate and pulse current charge-discharge. PBA consists of a structure of low strain open framework, and exhibits a redox potential (3.4 V v.s. Li/Li+) similar to LiFePO4. The PBA modified LiFePO4 cathodes show improved high-rate capability, with a 10 C discharge capacities of 15 % higher than pristine LiFePO4. It was found that the PBA modified LiFePO4 can endure high pulse current charge-discharge, which is well suited for green energy grids. The modified and pristine LiFePO4 cathodes were operated with alternate pulse currents of 0.01 C and 5 C introduced into a 0.2 C discharge/charge process to simulate the conditions of green grids. The modified LiFePO4 cathodes exhibited capacity retention of 92% under such conditions after 50 cycles, whereas the pristine sample showed capacity retention of only 75%. The results can be attributed to the reduction of electrode/electrolyte interface resistances due to the PBA coatings, as characterized by electrochemical impedance spectroscopy.
Flexible High Energy Density Silicon Composite Anode for Structural Batteries
Authors: Nazri Gholam-Abbas , Nazri Maryam 
Published: February 2020

The challenges of using high capacity metallic lithium foil as an anode for high energy density lithium battery are still remaining despite many years of research efforts, due to the intrinsic problems associated with the electrodeposition of reactive light metals such as lithium. In addition, the required excess lithium (3-5 times) to satisfy the battery long cycle life, and the safety concern associated with the large format cells containing metallic lithium anode have force the battery community to search for other alternatives. Some of the alternative anodes may exceed the energy density of metallic lithium when the excess lithium is considered. We will present a new class of composite anode material for structural and conformal lithium batteries. Our new composite anode is based on an optimized free-standing silicon coated carbon nanofiber in the form of flexible thin-paper with capacity exceeding 1500Ah/kg for the electrode including the carbon fiber and the silicon, and with high capacity retention during extensive charge-discharge cycles. The electrode/electrolyte interface and the silicon/carbon interface have been engineered to minimize the initial irreversibility during lithiation and delithiation, to less than 10%. In addition, the in-plan conductivity of the free standing composite anode has been optimized for high power battery application. We will report the performances of the silicon-carbon nanofiber composite anode in half cells and in full cells against high energy density lithium-rich layered oxide, and olivine based cathodes.
Impact of Nickel and Manganese Content on the Electrochemical Properties of Li1.13Mn0.54-X
Ni0.27+X
Co0.06O2 As Lithium Ion Battery Cathodes
Authors: Gao Min , Wang Zhenyao , Wang Zhong , Yin Yanping , Shao Zechao , Zhuang Weidong , Lu Shigang 
Published: February 2020

Introduction

In recent years, Li-rich, Mn-based Li[Li1-x-y
Me
x
Mn
y
]O2 (Me=Co, Fe, Cr, Ni, etc.) cathode materials have received world-wide attention for their high capacity (>250 mAhg-1) when operating at high voltage [1]. However, the cathode materials still suffer from poor rate capability and gradual capacity degradation during cycling, accompanied with hysteresis and voltage fade [2]. In order to overcome those issues, extensive studies have been performed to improve the electrochemical performance of Li[Li1-x-yMexMny]O2 cathode materials. Among all the factors investigated, it was found that Mn/Ni content of Li[Li1-x-yMexMny]O2 could be an important factor that limits the rate capability and influences the capacity/voltage fade [3]. As such, in this paper, we study the effects of Mn/Ni content of Li1.13Mn0.54-x
Ni0.27+x
Co0.06O2on structure, morphology, rate capability, capacity degradation and voltage fade during cycling.
Fig.1. The cycle performance of Li1.13Mn0.54-x
Ni0.27+x
Co0.06O2in the voltage range of 2.5-4.6 V at 1.0 C after three formation cycles in the voltage of 2.0-4.8 V at 0.1 C, (a) discharge capacity and (b) median voltage of discharge

Results and Discussion

Fig. 1 shows the capacity cycling performance (Fig. 1 (a)) and median voltage of discharge (Fig. 1 (b) of Li1.13Mn0.54-x
Ni0.27+x
Co0.06O2 (x=0, 0.02, 0.04, 0.06) in the voltage range of 2.5-4.6 V at 1.0 C after three formation cycles in the voltage of 2.0-4.8 V at 0.1 C. As shown in Fig. 1(a), it can be seen that initial discharge capacities decrease with x value increasing in the voltage of 2.0-4.8 V at 0.1 C ,during the formation cycles. Meanwhile, Li1.13Mn0.54-x
Ni0.27+x
Co0.06O2 (x=0, 0.02, 0.04, 0.06) delivers the initial discharge capacity of 181.0, 178.4, 157.6, 142.7 mAhg-1 in the voltage of 2.5-4.6 V at 1.0 C and capacity retention are 75.0, 87.2, 90.0 and 88.9% of an initial discharge capacity after 200 cycles, respectively. Fig. 1(b) shows the variation of median voltage of discharge of Li1.13Mn0.54-x
Ni0.27+x
Co0.06O2 (x=0, 0.02, 0.04, 0.06) over 200 cycles. It is noted that Li1.13Mn0.54-x
Ni0.27+x
Co0.06O2 shows much smaller voltage fade with x value increasing. Our results indicate that the Li1.13Mn0.54-x
Ni0.27+x
Co0.06O2 with lower Mn content and higher Ni content demonstrates much better electrochemical performance with high capacity retention and small voltage fade comparing to Li1.13Mn0.54Ni0.27Co0.06O2.

References

[1] M. M. Thackeray, S.-Ho Kang, C. S. Johnson, J. T. Vaughey, R. Benedek and S. A. Hackney, J. Mater. Chem., 17, 3112 (2007).
[2] J.R. Croy, K. G. Gallagher, M. Balasubramanian, B. R. Long, and M. M. Thackeray, J. Electrochem. Soc., 161(3), A318 (2014).
[3] E.-S. Lee, A. Manthiram, J. Mater. Chem. A, 2, 3932 (2014).

Figure 1
A New Strategy to Mitigate the Initial Capacity Loss of Lithium Ion Batteries
Authors: Su Xin , Lin Chi-Kai , Wang Xiaoping , Maroni Victor A. , Ren Yang , Johnson Christopher , Lu Wenquan 
Published: February 2020

Electrode materials and electrolyte choices largely dictate the design parameters and the type of lithium-ion battery (LIB) that can be optimized and eventually utilized. Certainly all three components (anode, electrolyte, and cathode) must work in harmony to produce the highest possible energy density achievable for an LIB-based energy storage device. Balancing the electrochemical performance characteristics of the cathode and anode active materials is critical for maximizing the power/energy density of a LIB. Hard carbon (non-graphitizable) anode materials, like tin, tin oxide, silicon and silicon oxide, have a high theoretical capacity (>550 mAh/g depending on their structural and chemical properties) but unfortunately they also exhibit a large initial capacity loss (ICL), which overrides the true reversible capacity in a full cell. Overcoming the large ICL of hard carbon in a full-cell lithium-ion battery (LIB) necessitates a new strategy wherein a sacrificial lithium source additive such as Li5FeO4 (LFO) is used on the cathode side. Full batteries using hard carbon coupled with LFO/LiCoO2 (LCO) are currently under development at our laboratory. We find that the reversible capacity of a cathode containing LFO can be increased by 24%. Furthermore, the cycle performance of full cells with LFO additive is improved from <90% to >95%. We believe that the LFO can not only address the irreversible capacity loss of the anode, but can also provide the additional lithium ion source required to mitigate the lithium loss caused by side reactions. In addition, we have explored the possiblity to achieve higher capacity on hard carbon, whereby the energy density of full cells can be increased from ca. 300 Wh/kg to >400 Wh/kg .
Towards Improving the Practical Energy Density of Li-Ion Batteries: Optimization and Evaluation of Silicon:Graphite Composites in Full Cells
Authors: Abu-Lebdeh Yaser , Yim Chae-Ho , Niketic Svetlana , Salem Nuha , Naboka Olga 
Published: February 2020

Increasing the energy density for Li ion batteries is very crucial for the success of EVs, grid-scale energy storage and next generation of power electronics.
A holistic approach is required where the performance of the electrodes and electrolyte needs to be improved simultaneously. On the anode side, Si has been considered as the best candidate to give much higher capacities reaching, in theory, 10 times those of graphite. [1,2] However, in practice Si alone cannot deliver this high capacity reversibly due to many problems associated with volume expansion/shrinking during lithiation/de-lithiation. Also, current cathode materials have limited specific capacity to 150-200 mAh/g and can only be coated up to certain thickness before fracture or polarization takes place. A composite of silicon and graphite with capacities between 500 and 1000 mAh/g has been considered as a transient and practical alternative. In this work we have conducted theoretical and experimental study of silicon, graphite, and binder composite electrodes. We have calculated the percentage of improvement in capacity of composites and in energy density of full cells. We have tested more than 50 compositions in half cells with different ratios, binder type and silicon (shape, size and surface chemistry). Also, we have tested full cells using NMC cathode, a carbonate solvent mixture and various additives.
We will show the result of our theoretical and experimental findings and demonstrate the actual parameters that need to be optimized in order to reach real improvements in practical energy density of Li-ion full cells.
[1] Chae-Ho Yim, Fabrice M Courtel, Yaser Abu-Lebdeh,Journal of Materials Chemistry, 1(28), 2013 8234.

[2] Nuha Salem, Matt Lavrisa and Yaser Abu-Lebdeh, 2015, Energy Technology, DOI 10.1002/ente.201500250.
Structural Design and Electrochemical Performances of Hollow Metal Oxide/Carbon Core-Shell Fibers
Authors: Zhou Dan , Li Meng , Fan Li-Zhen 
Published: February 2020

Transition metal oxide (MOx) offers great potential as anode for lithium ion batteries (LIBs) due to the high theoretical capacity compared with that of commercial graphite. However, several limitations, such as large volume variation during repeated cycling, slow kinetics and low electrical conductivity, have severely limited the practical performance in application. Here, we report a rational design of hollow metal oxide/carbon core-shell fibers (MOx/C, M= Sn, Ge) and the synthesis of the material via facile co-axial electrospinning process (Figure 1a). The unique hollow core-shell structure of MOx/C with MOx nanoparticles encapsulated into hollow carbon shells can provide a buffer layer to suppress the fracture of MOx nanoparticles caused by repeated volume changes, good conductivity and short diffusion paths for Li ions as well as stable solid electrolyte interphase (SEI) layer. Meanwhile, sufficient space between MOx nanoparticles and the carbon shell is contributed to accommodate the volume expansion of MOx during cycling process (Figure 1b–1c). As the anodes for LIBs, the as-prepared SnO2/C and GeOx/C electrodes exhibit excellent lithium storage performance, showing high reversible specific capacity of 833 mAh g−1 after 500 cycles at 600 mA g−1 and 875 mA h g−1 after 400 cycles at 160 mA g−1, respectively. The structural design in this paper can provide a novel strategy for the research of high-performance anode materials for LIBs.
References:
[1] Dan Zhou, Wei-Li Song, Li-Zhen Fan*. ACS Appl. Mater. Interfaces, 2015, 7, 21472−21478
[2] Meng Li, Dan Zhou, Wei-Li Song, Xiaogang Li, Li-Zhen Fan*. J. Mater. Chem. A, 2015, 3, 19907−19912.

Figure 1
Hard Carbon Coated Nano-Si/Graphite Composite As a High Performance Anode for Li-Ion Batteries
Authors: Jeong Sookyung , Li Xiaolin , Zheng Jianming , Yan Pengfei , Cao Ruiguo , Wang Chongmin , Liu Jun , Zhang Ji-Guang 
Published: February 2020

With the ever increasing demands on Li-ion batteries with higher energy densities, alternative anode with higher reversible capacity is required to replace the conventional graphite anode. Here, we demonstrate a cost-effective hydrothermal-carbonization approach to prepare the hard carbon coated nano-Si/graphite (HC-nSi/G) composite as a high performance anode for Li-ion batteries. In this hierarchical structured composite, the hard carbon coating layer not only provides an efficient pathway for electron transfer, but also alleviates the volume variation of silicon during charge/discharge processes. The HC-nSi/G composite electrode shows excellent electrochemical performances including a high specific capacity of 878.6 mAh g-1 based on the total weight of composite, good rate performance (398 mAh g-1 at 4C (2.4 mA g-1)) and a decent cycling stability (75.2% capacity retention over 150 cycles at 1.5 mAh cm-2 areal capacity loading), which is promising for practical applications.