bluuebunny/crossref_metadata_2025_split huggingface dataset:
Correlation Between Free Volume and Ionic Conductivity of Non-Aqueous Lithium Battery Electrolyte Solutions over a Wide Concentration Range
Authors: Abu-Lebdeh Yaser , Tam Jasper , Soboleski Hayden 
Published: February 2020

There is little known about the transport behavior of ions in electrolyte solutions at very high concentration and there is currently no satisfactory theory/equation to describe it [1,2]. In this work electrolyte solutions of lithium salts of various anions: [(CF3SO2)2N]°¥, (TFSI), [PF6]°¥ and [BF4]°¥ dissolved in polar solvents and solvent mixtures up to saturation have been prepared. The solvents are propylene carbonate (PC), acetonitrile (ACN), adiponitrile (ADN) and ethylene carbonate:dimethyl carbonate (1:1 v/v) (EC:DMC). The Ionic conductivity and density of the electrolyte solutions have been measured over a wide concentration range (up to 5.4 M).
The specific ionic conductivity (κ) vs. C plots show a non-ideal behavior with very strong dependence on concentration (a typical Gaussian-like function) while the molar conductivity (Λ) vs. C plots show an exponential decrease similar to the behavior of weak electrolyte solutions. The conductivity vs. concentration data were fitted to various equations of known models (Debye-Hückel-Onsager’s square-rate law: Λ vs. C^1/2, Cubic-root law: Λ vs. C^3, Casteel-Amis equation: κ/κmax vs. C/Cmax , or the corresponding state-law equation based on the pseudo-lattice theory: κ/κmax vs. C/Cmax .The models show good fit only in the low concentration, with the last two models fail to show universal behavior beyond the concentration of maximum conductivity, Cmax. However, we have derived a new, semi-empirical equation that shows a very good fit over the whole concentration range and can correlate molar ionic conductivity to changes in free volume within the liquid solution:
Λ = A' exp [-B C], B =-γ Vo/Vf, and Vf = V-Vo
Where Vƒ is the free volume which can be calculated from the difference between the measured volume, V, of the liquid (from density measurements) and the Van der Waal “molecular “volume, Vo, which can be obtained from XRD data at low temperatures or calculated using chemical models. C is concentration, A’ is a pre-exponential factor that can be related to limiting molar conductivity and square root of temerature. γ is a correction factor for overlapping holes with a value between 0.5 and 1.
These preliminary results are encouraging in bringing us closer to a free volume-based approach to explain the behavior of ionic conductivity of electrolyte solutions at very high concentrations. However, more work is underway to study more solutions with different chemical and physical properties, including aqueous solutions, to test the validity of this approach.
[1] S. I. Smedley, The Interpretation of Ionic Conductivity in Liquids, Springer, 1980
[2] C.A. Angell, J. Phys. Chem., 70, 1966, 3988
Superconcentrated Electrolytes for a High-Voltage Lithium-Ion Battery
Authors: Wang Jianhui , Yamada Yuki , Sodeyama Keitaro , Chiang Ching Hua , Tateyama Yoshitaka , Yamada Atsuo 
Published: February 2020

Finding a viable electrolyte for next-generation 5 V-class lithium-ion batteries is of primary importance. A long-standing obstacle has been metal ion dissolution at high voltages. The LiPF6 salt in conventional electrolytes is chemically unstable, which accelerates transition metal (TM) dissolution of the electrode material, yet beneficially suppresses oxidative dissolution of the aluminium current collector; replacing LiPF6 with more stable lithium salts may diminish TM dissolution but unfortunately encounters severe aluminium oxidation. Here we report a new electrolyte design that can solve this dilemma. By mixing a higly stable lithium salt with a solvent at extremely high concentrations, we obtain an unsual liquid showing a three-dimension network of anions and solvent molecules that coordinate strongly to Li+ ions. This new class of electrolytes inhibits the dissolution of both aluminium and TM at around 5 V, and realizes a high-voltage LiNi0.5Mn1.5O4/graphite battery that exhibits excellent cycling durability and high rate capability. Additionally, the electrolytes show superior thermal stability and flame retardant ability. Therefore, the superconcentrated electrolytes might offer many new opportunities in building safe and stable high-voltage batteries not limited to the lithium-ion.

Figure 1 Discharge capacity retention of high-voltage LiNi0.5Mn1.5O4/natural graphite batteries using lab-made superconcentrated and commercial dilute electrolytes. The inset shows EDS spectra on the graphite electrode surface after the cycling test. Charge and discharge were conducted at 40 °C with a current rate of 29.4 mA g−1 (C/5) on the weight basis of the LiNi0.5Mn1.5O4 electrode.

Figure 1
Effect of Calcination Temperature on the Characterizations of P-Type Na0.6Mn0.65Ni0.25Co0.10O2 Cathode Materials in Sodium-Ion Batteries
Authors: Nguyen Ngoc Anh , Kim Kyuman , Kim Yong Joo , Kim Sang Hern , Ryou Myung-Hyun , Lee Yong Min 
Published: February 2020

Recently, the demand for energy storage devices for electricity supply has been increasing remarkably. Lithium-ion batteries have already been popular power supplies for devices such as mobile phones, notebooks, digital devices and hybrid vehicles and so on. This increases the rate of lithium consumption; therefore, its cost has risen because of lithium source problem. Owing to abundant sodium resource and its low cost in comparison with lithium, sodium-ion batteries are promising for energy storage devices. Concerning cathode materials, layered NaxMO2 are classified into two main groups (O3 type or P2 type) in which the sodium ions are accommodated at octahedral and prismatic sites, respectively. Many works reported that P2-type structure exhibits a higher capacity and cyclability than O3-type structure. In this work, P-type Na0.6Mn0.65Ni0.25Co0.10O2 cathode materials were synthesized by a co-precipitation method. Effect of calcination temperature on the morphology, crystalline structure and electrochemical properties were investigated. Both P3-type (700 oC) and P2-type (800-1000 oC) structures were obtained at different calcination temperatures. In the cycling process, the P3-type material revealed a high discharge capacity of 136 mAh g-1 but a poor cycling performance. In contrast, the P2-type synthesized at 900 oC gave a highest specific discharge capacity of 148 mAh g-1and a more stable cycling performance and a good rate capability between 2.1 and 4.3 V.

Acknowledgement

This work was supported by the Human Resource Training Program for Regional Innovation and Creativity through the Ministry of Education and National Research Foundation of Korea (NRF-2014H1C1A1066977).

References

[1] C. Delmas, J. Braconnier, C. Fouassier, and P. Hagenmuller, Solid State Ionics, vol. 3–4, pp. 165–169, 1981.
[2] J. M. Paulsen and J. R. Dahn, Solid State Ionics, vol. 126, pp. 3–24, 1999.
[3] N. Yabuuchi, M. Kajiyama, J. Iwatate, H. Nishikawa, S. Hitomi, R. Okuyama, R. Usui, Y. Yamada, and S. Komaba, Nat. Mater., vol. 11, no. 6, pp. 512–517, 2012.

Figure 1
Low-Cost Sodium-Ion Batteries (LOCO-NIBs Project)
Authors: Salcianu Carmen , Titirici Maria-Magdalena 
Published: February 2020

The LOCO-NIBs (Low-cost Na-ion Batteries) Project funded by Innovate UK aims to investigate novel anode and cathode materials with compositions and morphologies which allow stable insertion and removal of sodium ions for a long number of cycles. This would facilitate the creation of energy storage systems of significantly lower cost due to the abundance of the sodium resources and materials implemented. This collaboration between School of Materials Science and Engineering at Queen Mary University of London (QMUL) and Johnson Matthey (JM) aims to develop low cost and highly performing electrode materials for sodium-ion electrodes based on abundant sodium resources and biomass derived low cost carbon electrodes. This will accelerate the development of sodium ion batteries which could be then integrated into battery modules, creating a new generation of competitive stationary battery systems increasing thus the security of supply, and the use of clean and locally generated energy sources such as solar and wind.
Most of the ongoing research in sodium-ion batteries relates to the development of cathodes where replacement of lithium by sodium has been a common route for finding good and low cost electrodes. Thus, a wide range of compounds are being currently studied as cathode materials from oxides to phosphates, fluorophosphates or pyrophosphates. Within this project we aim to investigate cathode candidate materials obtained by replacement or reduction in higher cost metal elements such as Co and Ni, with higher abundance, lower cost elements such as Fe and Mn, while improving cell voltage, capacity and cycling stability through accommodation of volume changes.
Much less research has been dedicated in the field to the anode material due to the inability of sodium to insert into graphite along with the formation of a stable solid electrolyte interface layer. Most of the proposed carbon materials as anodes in sodium ion batteries in the literature are expensive and derived from fossil-fuel precursors, using high-energy production techniques.
Following successful completion of the project, further development up the supply chain into cells and finally into sodium-ion battery based modules and systems is foreseen. The stationary market is predicted to grow in the near future. It is predicted that over 50,000 modules will be required by 2020. If this was the case then this would require 500 tonnes of combined anode and cathode materials. Interactions with energy companies, OEMS and other end users would also be anticipated, promoting the creation of a supply chain for electrical energy storage that would make an important contribution to economic growth and employment in the UK.
Mesoporous Lithium Titanate-Carbon Composite (Li4Ti5O12-Carbon) with Controlled Microstructure As Anode in Lithium Ion Batteries for Low Temperature
Authors: Ho Ching-Kit , Li Chi-Ying Vanessa , 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. [1-3]
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. Li4Ti5O12-carbon composites were built through impregnation of Li4Ti5O12 into the core-shell carbon. These Li4Ti5O12-carbon composites exhibit 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. 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.

References

1. 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.
2. 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.
3. 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.

Acknowledgements

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).
Fabrication of LiCoO2/Li2s-P2S5 Composite Cathode By Electrostatic Slurry Spray Deposition for All-Solid-State Lithium Ion Batteries
Authors: Park Chan Hwi , Son Seung Hyeon , Choi Lak Young , Lee Se Wook , Shin Dongwook 
Published: February 2020

The requirements of large scale lithium ion batteries such as electric vehicles (EV) and energy storage systems (ESS) have been attention. However, lithium ion batteries using liquid electrolytes have been badly reported of safety issues by its flammability. To resolve this issue, all-solid-state lithium ion batteries have been considered for candidate of next generation lithium ion batteries. The key material to realize all-solid-state lithium ion batteries is solid electrolytes with high conductivity and safety.
The ionic conductivity of solid electrolytes are currently attracting great attention. Several types of sulfide based electrolytes have been shown favorable lithium ion conductivities of 10-3-10-2 S/cm, which are comparable to those of liquid electrolytes, have been reported. In addition, those have several advantages of single Li ion conduction, good electrochemical stability over wide potential range.
However, all-solid-state cell has obstacle that is energy density of composite electrode lower than battery system using liquid electrolytes. It is difficult to make composite cathode with solid electrolytes for developing all-solid-state cells, that was required the continuous lithium ion and electron conducting paths. Inorganic solid electrolytes had lower contact area with active materials than liquid electrolytes, it was caused restrict ionic paths with active materials, and low electrochemical performance. In a large number of articles on all-solid-state lithium ion batteries using sulfide based electrolytes, composite electrodes were prepared by dry mixing. However, it is very difficult to control the particle mixture by dry mixing, it was caused low electrochemical performance. To conclude, an effective method for homogeneously mixed composite electrodes can improve the electrochemical performance of the all-solid-state lithium ion batteries.
In the present study, the LiCoO2/Li2S-P2S5 electrolyte composite cathodes were successfully fabricated by using the ESSD method for archive homogeneous thick film composite electrodes. The ESSD (Electrostatic Slurry Spray Deposition) process is unique method for thick film fabrication. The ESSD technique uses electrical energy to atomize and spray solutions. The ESSD technique is a method of spraying the slurry containing prepared powders. Dense film without any cracks and agglomeration can be easily fabricated by ESSD.
The composite cathodes were produced with differential cathode material / solid electrolyte ratio. Solid electrolytes were synthesized by mechanical milling method. In the deposited composite cathode thick films, all components homogeneously mixed, which were investigated by SEM and EDX. In addition, we made all-solid-state lithium ion batteries with composite cathode / solid electrolyte / In structure by uniaxial cold pressing method, which were successfully tested.
Lithium Garnet Based All-Solid-State Batteries By Spark Plasma Sintering
Authors: Hodkinson Jack 
Published: February 2020

Solid state electrolytes (SSEs) have a wider electrochemical and thermal stability window than either liquid or polymer electrolytes, making them a desirable component of high voltage lithium ion batteries. The superior thermal stability of SSEs reduces the need for added coolant in a multi-cell battery allowing for more efficient stacking. The SSE also provides structural stability, lending itself to smaller and inherently safer batteries.
Recently LISICON sulfates, perovskites and garnets have been investigated because they exhibit a highly mobile sub-lattice of lithium. Among these the lithium garnet Li7La3Zr2O12 is a suitable candidates for use as a SSE as it is stable against lithium metal. Room temperature ionic conductivities as high as 1.3 S/cm have been reported for the cubic phase of this material, however the thermodynamically stable tetragonal phase has an ionic conductivity orders of magnitude bellow the cubic phase. Higher conductivity values and stabilization of the cubic phase may be obtained by chemical substitution. The strategy adopted in this study is the substitution of Li for Al, Ga, In, and Sc; La for Ca, Sr, Ba and the lanthanide series; and Zr for Hf and Ta. The lithium occupation and local environment will be studied in these structures to give insight into the phase transition from the cubic to the tetragonal phase. Preliminary PXRD results have confirmed the cubic phase can be stabilized by substitution of 25% of Zr for Ta.
The structure of these garnets will be characterized by NMR and diffraction techniques. To avoid Li volatilization and the formation of undesirable reaction products, the garnets will be consolidated by spark plasma sintering. The ionic conductivities will be determined by pulsed field gradient NMR and impedance spectroscopy. Half cells will be assembled by sintering a layered composition of the electrolyte and active material. The half cells will be cycled against lithium and the electrolyte/electrode interface will be characterized by microscopy techniques. Compatible electrode materials will be determined in this way and an entire solid state cell will be assembled by spark plasma sintering. These cells will be characterized by impedance spectroscopy and an analysis of their charge discharge behavior will be performed.
Facile Chemistry Towards All Solid State Polymer Electrolytes and Lithium Ion Batteries
Authors: Liu Zhihong , Cui Yanyan , Cui Zili , Chai Jingchao , Wang Qingfu , Cui Guanglei 
Published: February 2020

Abstract: All solid state lithium batteries have been attracted intensive attention due to higher energy density and higher safety characteristics. Compared with inorganic solid state batteries, all solid polymer electrolyte lithium batteries possess advantages of readily processability and lower electrolyte/electrode interfacial impedance. These unique characteristics endow it a very promising power sources for large format application. However, the conventional fabrication for the solid polymer lithium battery involved a prefab solid polymer membrane laminated by the cathodes and anodes sheets. Herein an in situ polymerization process is developed to prepare all solid polymer electrolyte during the battery assembly. Some liquid precursors, such as epoxy compounds, are injected into battery and then catalyzed by LiFP6salt into all solid polymer electrolyte. In situ polymerization results in even lower electrolyte/electrode interfacial resistance, greatly improving the battery rate capability and cycling performance. These facile chemistry demonstrates a manufacturing innovation for all-solid-state polymer electrolyte batteries with cost-effectiveness and high performance.

Keywords:
solid polymer electrolyte, in situ polymerization, solid lithium battery;
Sodium Intercalation Mechanism into Hard Carbon
Authors: Tsai Ping-chun , Chung Sai-Cheong , Morikawa Yusuke , Nishimura Shinichi , Lin Shih-kang , Yamada Atsuo 
Published: February 2020

Sodium-ion battery is attracting much attention as large-scale energy storage devices, because sodium is an earth-abundant element and it is of low cost. Hard carbon is one of the most promising anode material for the sodium-ion battery owing to its large reversible capacity of ca. 300 mAhg–1[1]. However, the reaction mechanism has not been fully elucidated.
Both lithium and sodium can intercalate into hard carbon. Their charge–discharge curves show similar profiles, having a slope and a flat region, therefore the reaction mechanism has been considered to be similar. However, our ab initio calculations and experimental results revealed the clear differences. We built several models of hard carbon with two graphene sheets that have typical point defects (MV, DV, SW). Initially, sodium adsorption onto the point defects occurs well above the sodium plating potential, and induces expansion of interlayer distance of the two graphenes. Then, sodium intercalation into the interlayer space becomes possible[2]. On the other hand, lithium ions intercalate into the interlayer at the slope region followed by the aggregation into nanopores[3].
[1] D. A. Stevens and J. R. Dahn, J. Electrochem. Soc., 147 (4), 1271 (2000)
[2] P. Tsai et al., J. Mater. Chem. A, 3, 9763-9768 (2015)
[3] Park C. W. et al., Carbon, 38, 995-1001(2000)
A Perylene Anhydride Crystal As a Reversible Electrode for K-Ion Batteries
Authors: Xing Zhenyu , Jian Zelang , Luo Wei , Ji Xiulei , Hu Liangbing 
Published: February 2020

There is an ever-increasing demand for electrochemical power sources for electronics, electric vehicles and stationary storage, where currently Li-ion batteries (LIBs) dominate the market. However, the scarcity of lithium minerals causes a serious concern on LIBs’ sustainability in the decades to come, which motivates researchers to look for alternative technologies. To date, several Earth-abundant metal-ion batteries are under intense scrutiny, including Na-ion batteries (NIBs), Mg-ion batteries (MIBs) and Al-ion batteries (AIBs), where these technologies may provide sustainable solutions. However, exceedingly little attention has been paid to K-ion batteries (KIBs) despite the fact that potassium is nearly 1000 times more abundant than lithium in Earth’s crust. For KIBs, besides low cost, another advantage is its excellent adaptability to the existing carbon industry already developed for Li-ion batteries. Recently, we reported that both graphite and soft carbon can be used as anodes for KIBs with remarkable properties, where such materials exhibit very poor performance in NIBs. This is a significant advantage for KIBs over NIBs, which makes it very much urgent for the KIB field to develop more suitable cathode materials for a full cell design, where PTCDA is highly promising in filling up this gap.
We demonstrate that PTCDA is a promising cathode for K-ion batteries with a high capacity of about 122 mAh/g at 20 mA/g and moderate rate/cycling performance. Upon potassiation, PTCDA crystals experience a high level of amorphization, while upon depotassiation, the crystal structure is partially restored, revealed by ex situ XRD and IR. We will discuss the mechanism for the different performance between KIBs and NIBs. As shown in Figure 1, greater polarization between the discharge and charge profiles of PTCDA is observed in KIB than in NIB, which may be attributed to larger strain when intercalating of K ions into PTCDA and the associated slower diffusion of K ions.

F
ig. 1. The comparison of galvanostatic charge-discharge potential profiles of the PTCDA electrode in KIBs and NIBs, (a) the first cycle and (b) the second cycle.
We hope to present our results to bring attention to organic crystals that have intrinsic large interstitial sites for applications in Earth-abundant KIBs. The very different results of PTCDA in KIBs from in NIBs bring insights as well as questions that may attract further attention on this topic.

Figure 1