bluuebunny/crossref_metadata_2025 huggingface dataset:
Microstructure-Controlled 3D Electrodes for Lithium-Ion Batteries
Authors: Li Jie , Liang Xinhua , Panat Rahul , Park Jonghyun
Published: February 2020

A new concept for making battery electrodes to simultaneously control macro-/micro-structures of electrodes is developed to address present energy storage technology gaps and meet future energy storage requirements. This new fabrication process fully utilizes the benefits of additive manufacturing, which provides a pathway for inexpensive and flexible production of specialized products. Furthermore, the process allows a simultaneous control of the microstructure and macrostructure of electrodes which cannot be achieved via conventional manufacturing techniques. Modern batteries are fabricated in a form of laminated structures that are composed of randomly mixed constituent materials. Due to this randomness, there is an ample room in the conventional method to enhance performance by developing viable processing techniques to construct well-organized structures. The synergistic control of micro-/macro-structures is a novel concept in energy material processing that has considerable potential for providing unprecedented control of electrode structures and enhancing performance. Electrochemical tests show that the new electrodes exhibit superior performance in their specific capacity, areal capacity, and life cycle. It is concluded that the macro-micro-controlled structure showed 21%, 16%, and 7% more areal capacity than a structure with no control, a macro-controlled structure, and a micro-controlled structure, respectively The proposed control of 3D structures, with a well-organized distribution of energy materials, demonstrated more superior properties and advantages than structures with randomly distributed materials.
Experimental Study on Calendaristic Degradation and Self-Discharge of 3.4 Ah Lithium-Sulfur Pouch Cells
Authors: Knap Vaclav , Stroe Daniel Ioan
Published: February 2020

Lithium-Sulfur (Li-S) batteries represent one of possible development pathways of Lithium based batteries, which are expected to provide benefits of high volumetric energy density, various safety features and low production cost 1. Already nowadays, one can find demonstrated applications, which heavily depend on unique attributes of Li-S batteries, e.g. high-altitude long-endurance unmanned aerial vehicles capable to endure for an extended periods of time in air (currently proofed for 14 day without landing) 2. However, wide commercialization of Li-S batteries is still hindered mainly by their limited performance and short lifetime 3.

Both, cycling and storage, influence the Li-S battery lifetime. The degradation is often assigned to the irreversible relocation of polysulfides, which results into the corrosion of lithium metal anode, degradation of sulfur cathode and surface passivation of both electrodes 4. These degradation aspects were studied and discussed in literature into a certain degree; however, as pointed out in Ref. 3, some observations are possible to be done only at commercial-size cells, instead at coin cells, which determines the further focus of this work on a larger format cells, specifically pouch cells. The Li-S pouch cells were previously studied for an effect of cycling degradation on sulfur cathodes 5 and lithium metal anodes 6. The current study brings an experimental investigation of a capacity fade and a self-discharge with a periodic one month checking for storage of Li-S cells at various conditions of state-of-charge and temperature. The methodology presented in Ref. 7 is used for evaluation of the battery performance during the degradation in terms of capacity, resistance, power capability and shuttle current.

M. Wild, L. O’Neill, T. Zhang, R. Purkayastha, G. Minton, M. Marinescu, and G. J. Offer, Energy Environ. Sci., 8, 3477–3494 (2015).

http://defence.airbus.com/portfolio/uav/zephyr/, accessed at 20th November 2017.

T. Cleaver, P. Kovacik, M. Marinescu, T. Zhang, and G. Offer, J. Electrochem. Soc., 165, A6029–A6033 (2018).

S.-H. Chung and A. Manthiram, ACS Energy Lett., 1056–1061 (2017).

S.-E. Cheon, S.-S. Choi, J.-S. Han, Y.-S. Choi, B.-H. Jung, and H. S. Lim, J. Electrochem. Soc., 151, A2067 (2004).

X. B. Cheng, C. Yan, J. Q. Huang, P. Li, L. Zhu, L. Zhao, Y. Zhang, W. Zhu, S. T. Yang, and Q. Zhang, Energy Storage Mater., 6, 18–25 (2017).

V. Knap, D. I. Stroe, R. Purkayastha, S. Walus, D. J. Auger, A. Fotouhi, and K. Propp, ECS Trans., 77, 479–490 (2017).

Figure 1
Cathode Nanostructuring and Separator Modification for High-Performance Lithium-Sulfur Batteries
Authors: Yu Xiaoyun , Zhou Guangmin , Cui Yi
Published: February 2020

Battery technologies involving Li-S chemistry are promising approaches to realize inexpensive and high energy density storage for sustainable energy applications. However, current Li-S batteries still suffer from short life-time due to active material loss through the soluble polysulfide molecules shuttling between battery cathode and anode.[1] We present herein our recent advances in the understanding of the electrochemical reactions at Li-S battery cathode and addressing the shuttle effect by polysulfide trapping. Specifically, an in-operando characterization technique based on optical microscopy is developed to intuitively visualize the selective deposition of sulfur and Li2S in battery cathodes, and the critical roles of current collectors and additives, including different metals and semiconductors, are demonstrated. Accordingly, innovative cathode architectures are designed to control the oriented deposition and diffusion of sulfur-containing species. In particular, an ultrathin and compact blocking layer of 2D MoS2 and WS2 nanoflakes, with a thickness of ca. 15 nm, are deposited on separator through a solution based self-assembly method,[2] which effectively adsorb polysulfide molecules and thus suppress their diffusion to the battery anode. In addition, Li2S-metal composites and polymer-metal hybrid networks are fabricated as hosts for sulfur cathodes to enable rapid battery charge-discharge processes given the large active surface area and better control of charge (or discharge) product deposition.[3] Combining these two strategies, we report greatly enhanced specific capacity (over 1200 mAh g-1) and cyclability (over 500 cycles) for the nanostructured sulfur cathodes compared to the conventional carbon-sulfur based cathode, and the routes to further improving high-energy and long-life Li-S battery are discussed.

[1] Seh, Z. W.; Sun, Y.; Zhang, Q.; Cui, Y. Chem. Soc. Rev. 2016, 45, 5605.

[2] Yu, X.; Prévot, M. S.; Guijarro, N.; Sivula, K. Nat. Commun. 2015, 6, 7596.

[3] Zhou, G. M.; Sun, J.; Jin, Y.; Chen, W.; Zu, C. X.; Zhang, R. F.; Qiu, Y. C.; Zhao, J.; Zhuo, D.; Liu, Y. Y.; Tao, X. Y.; Liu, W.; Yan, K.; Lee, H. R.; Cui, Y. Adv.
Mater. 2017, 29, 1603366
Orthotellurate Cathode Frameworks for Potassium-Ion Battery
Authors: Masese Titus , Yoshii Kazuki , Okumura Toyoki , Senoh Hiroshi , Shikano Masahiro
Published: February 2020

As a low-cost alternative to lithium, potassium-ion battery (PIB) has recently attracted great attention. PIB can be a high-voltage contender considering the significantly negative potential of the K+/K redox couple, which is close to or even lower than Li depending on the solvent [1,2]. Nonetheless, the large ionic radius of potassium coupled with significant strain accompanying potassium (de)insertion, the number of potassium-based compounds (particularly, cathode materials) that can practically be utilized is limited.

Exploration of the broad class of orthotellurate frameworks based on K6TeO6 has led us to identify new cathode frameworks that can reversibly (de) insert potassium ions, not only at high voltage but also at decent capacities. Figure 1 shows a layered crystal structure of K2Ni2TeO6, a new cathode material synthesized via the conventional solid state method. The structure entails a honeycomb-like network of NiO6 octahedra (in purple) surrounding each TeO6 octahedon (in blue). Potassium atoms (in brown) occupy trigonal prismatic sites sharing faces with NiO6 or TeO6 octahedra.

During the meeting, we will highlight the synthesis, crystal structure and electrochemical performance of K2Ni2TeO6 as a new cathode material for PIB [3].

Reference
s
:

[1] Y. Marcus, Pure Appl. Chem., 57 (1985) 1129-1132.

[2] S. Komaba, T. Hasegawa, M. Dahbi and K. Kubota, J
.
Power Sources,
60 (2015) 172-175.

[3] T. Masese, K. Yoshii, T. Okumura, H. Senoh, M. Shikano, manuscript submitted.

Figure 1. Schematic presentation of K2Ni2TeO6 viewed along [110] direction. NiO6

tetrahedra (blue), TeO6 octahedra (purple), and K atoms (brown) are illustrated.

Figure 1
A High-Voltage Aqueous Electrolyte for Sodium-Ion Batteries
Authors: Reber David , Kühnel Ruben-Simon , Battaglia Corsin
Published: February 2020

Due to their inherent safety, environmental friendliness, and potential low cost, rechargeable batteries based on aqueous electrolytes are being developed as a large-scale energy storage option for grid applications to enable wide spread integration of renewables. In this field cost and safety are more important than energy density, which is why water based systems are a promising candidate. So far, operational voltages of aqueous batteries have been too low to enable market penetration due to the narrow electrochemical stability window of water (~1.23 V). Using highly-concentrated aqueous sodium bis(fluorosulfonyl)imide (NaFSI) solutions (35m), we recently reported a stability window of 2.6 V on stainless steel current collectors1. Meanwhile addressing the raw materials supply chain as important challenge for scaling, we developed an aqueous sodium-ion battery employing only non-critical raw materials, namely NaTi2(PO4)3
2 and Na3(VOPO4)2F3 on the anode and cathode side, respectively. The average discharge voltage is 1.5 V, whereas the 35-molal NaFSI aqueous electrolyte allowed us to use the full capacity of the high-voltage cathode material. Due to the enhanced oxidative stability of the electrolyte, this battery displays an energy density that is almost twice as high as that of previously reported aqueous sodium-ion batteries4.

Kühnel, R. S.; Reber, D.; Battaglia, C., A High-Voltage Aqueous Electrolyte for Sodium-Ion Batteries. ACS Energy Lett.
2017,
2 , 2005.

Li, Z.; Young, D.; Xiang, K.; Carter, W. C.; Chiang, Y.-M., Towards High Power High Energy Aqueous Sodium-Ion Batteries: The NaTi2(PO4)3/Na0.44MnO2 System. Adv. Energy Mater.
2013,
3, 290.

Qi, Y.; Mu, L.; Zhao, J.; Hu, Y. S.; Liu, H.; Dai, S., Superior Na-Storage Performance of Low-Temperature-Synthesized Na3(VO(1-x)PO4)2F(1+2x) (0≤x≤1) Nanoparticles for Na-Ion Batteries. Angew. Chem. Int. Ed.
2015,
54, 9911.

Kumar, P. R.; Jung, Y. H.; Wang, J. E.; Kim, D. K., Na3V2O2(PO4)2F-MWCNT nanocomposites as a stable and high rate cathode for aqueous and non-aqueous sodium-ion batteries. J. Power Sources
2016,
324, 421.
Preparation of Disordered Carbon Anode By Mechanical Method for Sodium Ion Battery
Authors: Lee Su Chan , Chung Kyung Yoon , Jun Seong Chan
Published: February 2020

The application of energy storage device is sharply expanding its application area from small portable mobile devices to large-scale energy storage systems (ESS). The cost of energy storage device has become more important as the demand of large-scale device expands. The outstanding performance such as large energy density of lithium ion battery (LIB) makes itself a most powerful energy storage device. However, LIB has some growing concerns about cost due to its limited reserves of raw materials. For large-scale ESS, alternative energy storage system other than LIB with low price and moderate performance is required. There have been extensive studies on various types of energy storage devices meet these demands, and sodium ion battery (SIB) is one of the most promising candidate. Sodium ion, which is an alkaline metal, has similar characteristics with lithium ion even though it is earth abundant metal. Researchers have started the sodium ion battery study by focusing on these similarities and the main purpose of this study is to develop the post-LIB with low cost. The main difference between sodium and lithium ion is potential difference ((E0
Na/Na+=-2.71 V and E0
Li/Li+=-3.04 V) and ionic radius. Many materials have been studied for SIB electrode, but only a few materials achieve a certain level of performance even though those candidate materials show good lithium ion storage performance. The ionic radius difference between sodium and lithium ion is thought to be main cause of this phenomena. Especially in case of anode, the graphite was most powerful LIB anode material with low price and good performance but graphite has very low capacity with sodium ion. So there are many efforts to develop SIB anode to achieve similar performance level graphite of LIB. The main advantage of SIB is a low cost, therefore the research of SIB anode should be conducted with considering the price efficiency. To meet this point, the anode of SIB should be developed with carbon material, which has low price of raw material.

In this presentation, the fabrication of disordered carbon with mechanical method for SIB anode will be reported. The facile and cost-effective mechanical milling process can make high quality disordered carbon and it has good sodium ion storage performance. The sodium ion storage mechanism of mechanically milled disordered carbon also will be presented. The details will be discussed at the meeting.
Na-Ion Full Cell: Electrochemical Study Using Prussian Blue Cathode and Tin Sulphide (SnS) Anode with Additive-Free Ether-Based Electrolyte System
Authors: Dutta Prasit Kumar , Mitra Sagar
Published: February 2020

Nowadays sodium-ion battery technology is becoming more popular among researcher as it has been considered as an alternative to lithium-ion batteries. As an alternative to the state-of-the-art lithium-ion battery technology, sodium-based research needs to come out with an easily adaptable option satisfying adequate energy density which can cover the dearth of the demand for lithium-ion batteries in near future. However, the current sodium technology is still lacking to reach enough energy requirement at the cheaper price point. Recent research trend has arrogated hard carbon anode as conventional graphite is still not an adequate performer for sodium. In addition, NVP has been chosen as one of the best options as cathode due to having higher energy density. Combining NVP and hard carbon, carbonate-based electrolyte with an additive (FEC) is conjunct to build a sodium-ion full cell.1 However, the overall cost of producing this system is still high compared to lithium technology.2 Hence, achieving an adequate energy density at low-cost is an open challenge for the current generation researchers.

In this work, we merge two systems: an alloy-based anode and high rate capable cathode in conjunction with an additive-free electrolyte. For the first time, a Na-ion full cell is fabricated combining SnS anode,3 Prussian blue (PB) cathode and NaClO4-TEGDME electrolyte.4 The electrodes were used without any carbonaceous coating. In addition, both the electrode materials were prepared using a rapid bulk synthesis pathway which benefits the time of material preparation, hence can easily be applied in large-scale production. The cathode works nearly 3 V vs. metallic sodium while the anode works mostly below 1.2 V (Fig. 1a). Hence, the overall combination produces an average of 1.8 V full cell (Fig. 1d). Capacity coming from the full cell is nearly 80 mAh g-1
PB (Fig 1c) which corresponds to 135 Wh Kg-1 for the gravimetric energy density. Fig. 1b demonstrates that a single coin cell is capable of powering a LED lamp.

Figure 1
Operando X-Ray Diffraction and EIS on NCA Battery Cathodes
Authors: Passarello Donata , Takacs Christopher J , Steinrueck Hans-Georg , Toney Michael F
Published: February 2020

In recent decades, lithium-ion batteries (LIB) have revolutionized the portable electronics industry and the emerging market of electric vehicles (EVs) and hybrid electric vehicles (HEVs). Significant efforts have been devoted to fundamental and commercial research and development of layered oxide cathodes with small structural deformation upon lithium intercalation and de-intercalation. Towards this end, there is a need to couple modern electroanalytical techniques with advanced structural characterization methods.

Here I discuss current progress to complement electrochemical impedance spectroscopy (EIS) with in operando x-ray methods, focusing on correlating time-dependent measurements in order to add structural information to the electrochemical models. EIS is widely used as a measure of kinetics and interface properties in a wide variety of systems. In a battery system, correlating the impedance parameters to the cycling efficiency of the cell, helps predicting the likelihood of battery failures. While EIS is a very powerful analysis tool, the interpretation of the data is non-trivial, as they can`t be fit by a unique model. In this study, we investigate the structural behavior of LiNi0.80Co0.15Al0.05O2 (NCA) cathode material, of particular interest as it exhibits high structural stability. We aim to gain additional structural information from x-ray diffraction methods in order to unambiguity model the EIS data.
Anatase TiO2 Nanoparticles Supported By Cu/Ni Micro-Channeled Current Collector as a Novel Electrode for Lithium-Ion Batteries
Authors: Yue Yuan , Liang Hong
Published: February 2020

Transition metal oxides (TMOs), a typical materials family for electrodes of lithium-ion batteries (LIBs), have unstable capacity performance and lack of durability after combining with a flat current collector. Novel designs of both active materials and current collectors are necessary to eliminate those issues. In this work, a hierarchical micro-electrode for LIBs is successfully designed and fabricated. Anatase TiO2 nanoparticles (diameter ~100 nm) are synthesized as the active materials. A porous Cu/Ni current collector with vertically-aligned Ni micro-channels supports TiO2 active materials. Electrochemical characterizations illustrates that such electrode has enhanced capacity, stable rate performance, and durable lifespan. The maximum insertion coefficient for the Li ion intercalation reaction is as high as ~0.85, which is one of the greatest results for anatase LIB anodes. Furthermore, cross-sectional electron microscopic imaging along with X-ray energy dispersive spectroscopic elemental analysis confirmed the uniform spatial distribution of TiO2 nanoparticles inside the Ni micro-channels. This distribution is maintained after numbers of cycles. A synergistic effect between nano-TiO2 active material and porous Cu/Ni current collector is the main reason. The favorable properties of the Cu/Ni/TiO2 anode are improved electrochemical reactivity, reduced lithium ion diffusion pathways, great specific surface area, effective buffering of volume changes of TiO2 nanoparticles, and the optimal paths for chargers transport.
Nano-Confined Sulfur/CNT Composite As Cathode for Li-S Batteries
Authors: Lee Glenn , Hao Yong
Published: February 2020

Sulfur is one of the most promising cathode candidates for lithium batteries for emerging advanced energy storage technology, portable electronics, electric vehicles, and grid-scale energy station. Its overwhelming advantages include abundance, low cost, environmentally friendly and most importantly, high theoretical capacity (1675 mAh g-1) and energy density (2600 vs 387 Wh kg-1 of traditional Li-ion batteries) [1-3]. However, there are major issues which hindered the practical application of lithium-sulfur (Li-S) batteries such as rapid fading of specific capacity, low columbic efficiency and low cycle life due to the “shuttle effect” during charge/discharge process. Here, we present a study using acid treated carbon nanotubes (CNT) as a nano-confinement material for sulfur to develop high areal loading and areal capacity sulfur/CNT composite as cathode for Li-S batteries with a goal to achieve high performance with high specific capacity and long cycle life [4]. During the synthesis process, CNT is segmented to relatively short length followed by chemical reaction deposition and heat treatment to encapsulate sulfur. Morphology of the electrode is characterized by SEM. Crystal structures and mapping results of the sample are determined by XRD and EDS. The sulfur loading in the composition is determined by TGA. Surface characterization is investigated by FTIR. Electrochemical testing is further performed in half-cells using lithium foil as counter and reference electrode and evaluated by cyclic-voltammetry (CV), galvanostatic charge/discharge cycle test and electrochemical impedance spectroscopy (EIS). The detailed results of specific capacity, rate capability, and cyclability will be presented and discussed during the conference.

References:

Melot, B.C. and Tarascon, J.M., 2013. Design and preparation of materials for advanced electrochemical storage. Accounts of chemical research, 46(5), pp.1226-1238.

Evers, S. and Nazar, L.F., New approaches for high energy density lithium–sulfur battery cathodes. Accounts of chemical research, 46(5), 2012. pp.1135-1143.

Manthiram, A., Fu, Y. and Su, Y.S., Challenges and prospects of lithium–sulfur batteries. Accounts of chemical research, 46(5), 2012. pp.1125-1134.

Li, M., Carter, R., Douglas, A., Oakes, L. and Pint, C.L., 2017. Sulfur Vapor-Infiltrated 3D Carbon Nanotube Foam for Binder-Free High Areal Capacity Lithium–Sulfur Battery Composite Cathodes. ACS nano, 11(5), pp.4877-4884.
Expanded Biomass-Derived Hard Carbon with Ultra-Stable Performance for Sodium-Ion Batteries
Authors: Zhang Yingjie , Zhu Ziyi , Li Xue , Dong Peng
Published: February 2020

As a new generation of high performance integrated energy storage battery system, the key factor in the development and application of sodium-ion batteries (SIBs) are the high-performance electrode materials. As a kind of hard carbon, the biomass-derived carbon has attracted much attention from experts and scholars due to the characteristics of rich-resource, low-cost and simple preparation process. It also can maintain the natural properties of biomass precursors, which contribute to the improvement of electrochemical performance. In the present work, cherry petals were used as precursors to prepare a hard carbon (CP) by a facile preparation. When it was used as an anode material for SIBs, CP exhibits high storage capacity with a high initial reversible capacity (310.2 mAh g-1), outstanding cyclic stability (the capacity retention rate was 99.3% after 100 cycles at 20 mA g-1) (Figure 1), favorable rate capability (146.5 mAh g-1, even at a very high current density of 500 mA g-1) and a high initial coulomb efficiency of 67.3%. In particular, approximate 45% of the capacity from CP is contributed by sodiation below 0.1 V (vs. Na+/Na). This low potential plateau makes CP energetically favorable as an anode material. The excellent electrochemical properties of CP can be attributed to its "open" lamellar structure-associated the nanoscale mesoporous, the presence of nitrogen/oxygen functional groups on the surface, and expanded interlayer distance (~0.44 nm) (Figure 2).

Figure captions

Figure 1. Cycling performance of CP (at 20 mA g-1).

Figure 2. (a) HRTEM and SAED images of CP; (b) Contrast profiles along the arrows indicate interlayer distance of CP.

References

[1] Qiu S, Xiao L, Sushko M L, Han K S, Shao Y, Yan M, et al. Manipulating adsorption-insertion mechanisms in nanostructured carbon materials for high-efficiency sodium ion storage. Adv. Energy Mater. 2017; 7: 1700403.

[2] Liu, P, Li, Y, Hu, Y. S, Li, H, Chen, L, Huang, X. A waste biomass derived hard carbon as a high-performance anode material for sodium-ion batteries. Journal of Materials Chemistry A 2016; 4: 13046-13052.

Figure 1
Lithiation Effect of the Poly(Acrylic Acid) Binders on the Silicon Anode of Lithium-Ion Batteries
Authors: Hu Bin , Jiang Sisi , Zhang Jingjing , Zhang Zhengcheng , Zhang Lu
Published: February 2020

The exploration for the next generation of anode materials in the lithium-ion batteries is a vital subject in the past few years due to the huge demand of high capacity batteries. Silicon (Si) stands out as a promising anode material due to its high theoretical specific capacity (4200 mAh/g), enviroment friendliness and low costs. However, Si nanoparticles (NPs) experience severe volume changes up to 300 % during the lithiation/delithiation process, which leads to dramatic particle degradation and thus capacity loss. Novel polymeric binders with enhanced mechanical properties have been identified as one effective approach to alleviate this issue, and some examples include carboxymethyl cellulose (CMC), alginate, and poly(acrylic acid) (PAA), etc. By using those binders, cell performance has been greatly improved as compared to the conventional polyvinylidene fluoride (PVDF) binder. Among those candidates, PAA outperforms others possibly due to its superior mechanical properties. In this report we have attempted to investigate the lithiation effect of the PAA binders. Lithiating PAA binders could benefit the electrode laminate processing as well as cycling performance. A commercially available PAA sample with a characterized Mn of 147 kDa was used in this study. By titrating with LiOH solution, we controlled the pH of 10 wt% PAA solutions as well as the lithiation ratio (Table 1). Those binder solutions were used to fabricate silicon/ graphite composite electrodes that composed of 10 % PAA, 73 % Hitachi MagE, 15 % Si NPs (NanoAmour, 70-130 nm), and 2 % Timcal C45. Half-cell cycling results (Figure 1) indicated that different lithiation of PAA binders has dramatic impact on their corresponding cycling performance. Lower lithiation tends to afford higher initial specific capacities and better capacity retentions. Actually, the best performer is PAA binder with no lithiation at all. This result is a little contradicting to previous study but we reason that our lithiation agent, LiOH, may have side reasons with silicon particles, as evidenced by the dramatic decrease of the silicon capacity. Full cell cycling as well as further characterization of electrode surface is ongoing.

Table 1. The calculated mol% of LiOH (to AA monomer) and the resulting pH values of the final PAA solutions.

LiOH %
0
25
50
75
85
90
91
92.5
95
100

pH
2.08
4.22
4.84
5.49
5.97
6.97
10.03
11.96
12.28
12.59

Figure 1. Specific discharge capacity and Coulombic efficiency of PAA binders with different pH values.

Figure 1
Understanding the Role of Li Inventory on Capacity Fade in Silicon Containing Anodes
Authors: Dose Wesley M , Maroni Victor A. , Piernas-Muñoz María José , Cui Yanjie , Bloom Ira , Johnson Christopher
Published: February 2020

Silicon containing anodes are an attractive alternative to graphite since the inclusion of intrinsically high capacity Si dramatically increases the energy density in a full Li-ion battery. However, problems persist with Si related to SEI formation/exfoliation, pore filling, and particle agglomeration due to >300% volume changes. This leads to severely limited Li diffusion kinetics and hence capacity fade. In this work we assess the impact of Li inventory on the capacity fade of Si containing electrodes by pairing them with a LiFePO4 reference/counter electrode. Using a capacity limited cycling protocol we assess the role of Li inventory in prolonging the lifetime of Si. We also explore the synergistic effects that arise from blending graphite with Si in composite electrodes. Overall, we relate the observed electrochemical behavior to the evolution of the local structure, electrode morphology and mechanical properties.
Macro- and Micro-Porous Biomass Derived Carbon for Various Energy Storage Application
Authors: Kim Kyungho , Youngblood Jeffrey P. , Pol Vilas G.
Published: February 2020

Recent research in electrochemical storage devices focus not only on improving lithium ion batteries technique (e.g. safety, energy density) but also on utilizing different storage types such as sodium ion batteries, lithium sulfur batteries, and super-capacitors. Among various topics of energy storage devices, biomass derived carbon has attracted interest for its economic and environment benefits. Pistachio shell has been used in this study for its structural benefits for various energy storage application. Pistachio shell derived carbon (PC) shows a macroporous channel and micro-pores architecture. The macroporous channel enables facile penetration of ions and electrolyte into the material while micro-pores provides more active sites and withstand the volume expansion of ions during repeated charge/discharge cycles. This makes this material attractive for lithium ion / sodium ion / lithium sulfur batteries and even super-capacitor. In this work, the characteristics of pistachio shell structure and its performances in sodium ion and Li-S batteries is presented. The optimum carbonization temperature for pistachio shell is studied to maximize the performance in sodium ion batteries. In-depth study on plausible sodium storage mechanism by understanding the characteristics of PC (surface area, crystal information) at different temperature is conducted as well. Further application using PC as a sulfur reservoir to restrict the polysulfide shuttling effect in Li-S batteries is purposed. Fundamental study (e.g. Raman, XPS, SEM) on how PC structure and chemical anchor improves the cyclability of Li-S batteries is discussed. This work successfully shows promising result with using pistachio shell in different energy storage systems.

Figure 1
Surface Chemistry Mechanism of Ultra-Low Interfacial Resistance in the Solid-State Electrolyte Li7La3Zr2O12
Authors: Sharafi Asma , Kazyak Eric , Davis Andrew L. , Yu Seungho , Thompson Travis , Siegel Donald J , Dasgupta Neil P. , Sakamoto Jeff
Published: February 2020

The garnet-type solid-state electrolyte, based on the nominal formula Li7La3Zr2O12 (LLZO), is unique in that it is a fast Li-ion conductor, exhibits sufficient mechanical properties, and is also chemically and electrochemically stable against metallic Li. Despite these promising attributes, additional challenges must be overcome before solid-state batteries based on LLZO are viable. Demonstrating low Li–LLZO interfacial resistance (R
Li–LLZO) is a critical milestone along the path to commercialization. While several studies have characterized R
Li–LLZO, nearly all report values significantly higher than conventional LIBs employing liquid electrolytes. Thus, strategies to reduce R
Li–LLZO to values comparable to, or lower than, LIBs are needed [1].

In this study, the impact of surface chemistry on the interfacial resistance between the LLZO solid-state electrolyte and a metallic Li electrode is revealed [1]. Control of surface chemistry allows the interfacial resistance to be reduced to 2 Ω cm2, lower than that of liquid electrolytes, without the need for interlayer coatings. A mechanistic understanding of the origins of ultra-low resistance is provided by quantitatively evaluating the linkages between interfacial chemistry, Li wettability, and electrochemical phenomena. A combination of Li contact angle measurements, X-ray photoelectron spectroscopy (XPS), first-principles calculations, and impedance spectroscopy demonstrates that the presence of common LLZO surface contaminants, Li2CO3 and LiOH, result in poor wettability by Li and high interfacial resistance. On the basis of this mechanism, a simple procedure for removing these surface layers is demonstrated, which results in a dramatic increase in Li wetting and the elimination of nearly all interfacial resistance. The low interfacial resistance is maintained over one-hundred cycles and suggests a straightforward pathway to achieving high energy and power density solid-state batteries.

[1] A. Sharafi, E. Kazyak, A. L. Davis, S. Yu, T Thompson, D. J. Siegel, N. P. Dasgupta, J. Sakamoto, Chem. Mater.
29, 7961(2017)
Grain Boundary Contributions to Li-Ion Transport in the Solid Electrolyte Li7La3Zr2O12
Authors: Yu Seungho , Siegel Donald J
Published: February 2020

The oxide with nominal composition Li7La3Zr2O12 (LLZO) is a promising solid electrolyte thanks to its high (bulk) Li-ion conductivity, negligible electronic transport, chemical stability against Li metal, and wide electrochemical window. Despite these promising characteristics, recent measurements suggest that microstructural features, specifically, grain boundaries (GBs), contribute to undesirable short-circuiting and resistance in polycrystalline LLZO membranes. Toward the goal of understanding GB-related phenomena, the present study characterizes the energetics, composition, and transport properties of three low-energy (∑3 & ∑5) symmetric tilt GBs in LLZO at the atomic scale. Monte Carlo simulations reveal that the GB planes are enriched with Li, and to a lesser extent with oxygen. Molecular dynamics simulations on these off-stoichiometric boundaries were used to assess Li-ion transport within and across the boundary planes. We find that Li transport is generally reduced in the GB region; however, the magnitude of this effect is sensitive to temperature and GB structure. Li-ion diffusion is comparable in all three GBs at the high temperatures encountered during processing, and only 2-3 times slower than bulk diffusion. These similarities vanish at room temperature, where diffusion in the more compact ∑3 boundary remains relatively fast (half the bulk rate), while transport in the ∑5 boundaries is roughly two orders of magnitude slower. These trends mirror the activation energies for diffusion, which in the ∑5 boundaries are up to 35% larger than in bulk LLZO, and are identical to the bulk in the ∑3 boundary. Diffusion within the ∑5 boundaries is observed to be isotropic. In contrast, intra-plane diffusion in the ∑3 boundary plane at room temperature is predicted to exceed that of the bulk, while transboundary diffusion is ~200 times slower than bulk. Our observation of mixed GB transport contributions (some boundaries support fast diffusion, while others are slow) is consistent with the limited GB resistance observed in polycrystalline LLZO samples processed at high temperatures. These data also suggest that higher-energy GBs with less-compact structures should penalize Li-ion conductivity to a greater degree.
Constructing Sulfone Based Electrolyte System for High Energy Density Li-S Batteries
Authors: Shin Woochul , Stickle William F. , Ji Xiulei
Published: February 2020

Development of electric vehicle has led ever increasing demand of high energy density lithium ion batteries such as Li-sulfur, and Li-oxygen batteries. In this regard, lithium metal received huge attention as an anode due to the high specific capacity (3,860mAh/g) and the lowest electrochemical potential (-3.04V versus standard hydrogen electrode). However, nature of lithium metal is giving rise to safety concerns including uncontrollable dendrite growth, chemical reaction with organic electrolyte, and volume change while cycling, which also result in poor cycling performance. Due to those reasons, broader use of lithium metal as an anode was hindered in the commercialized field.

Here, we introduce Ethyl Methyl Sulfone (EMS) as a co-solvent in a typical electrolyte system, 1,3-Dioxolane (DOL) and Dimethyl ether (DME) to tackle those challenges. Adding EMS into the DOL/DME shows outstanding performance of suppressing dendrite growth as well as retaining good cycling stability proven by Li|Li symmetric cells and Li|Cu cells respectively. Scanning Electron Microscopy (SEM) showed non-dendritic surface of lithium metal unlike needle-like dendrite surface of control sample (DOL/DME only). Energy Dispersive X-ray Spectroscopy (EDX) also showed well-dispersed fluorine and sulfur elements and XPS analysis was conducted to prove the existence of Solid Electrolyte Interface (SEI) composed of lithium-sulfur-carbon(oxygen) mixed with lithium fluoride. We suggest sulfur in EMS act as crosslinking agents to form robust SEI that holds volume expansion, dendrite growth, and continuous lithium consumption which leads higher C.E. than DOL/DME system. Lastly, lithium metal was paired with sulfur cathode in coin cells to show better cycling performance, which can be further used in Li-S environments.
NMR Diffusion Study of Ionic Liquids and Ionogels for Use in Lithium Ion Batteries
Authors: Jayakody Nishani Kanchana , Gobet Mallory , Greenbaum Steven , Ashby David , Dunn Bruce S.
Published: February 2020

Solid-state electrolytes have been explored increasingly for use in Li+ batteries on account of their ability to address the safety issues, packaging constraints, and volumetric design concerns associated with liquid electrolytes. Recently, ionogels, pseudo-solid-state electrolytes consisting of an ionic liquid electrolyte confined in a mesoporous inorganic matrix, have attracted interest because of their high ionic conductivity, stability, and solution processability. Due to the complexity of the trapped liquid, the nature of the ion interaction and movement is not well established. Understanding how the ions behave inside the matrix is paramount for increasing the ionic conductivity and Li+ transference number. The literature for these characteristics is lacking in several key areas including, but not limited to, variations in the electrolyte’s Li+ concentration, the choice of silica precursors, and diffusion under different conditions.

The ionogel matrix was synthesized using a non-aqueous organic acid catalyzed sol-gel process to form a nanoporous silica matrix around an ionic liquid, BMIM TFSI with variable amounts of LiTFSI added, thus confining the electrolyte. The choice of silica precursors and use of an organic acid allows for a crack free monolith to form under rapid gelation conditions. The silica component maintains a highly porous network with surface areas up to 1300 m2/g and an average pore size of 20nm as measured through N2 adsorption. The ionic liquid (IL) electrolyte component constitutes 75 vol% of the ionogel. Thermal gravimetric analysis shows that the ionogel is thermally stable to 400 oC. Due to the interconnected porosity and large percentage of liquid, conductivities of ̴10-3 S/cm were measured at room temperature for the prepared monoliths using electrochemical impedance spectroscopy (EIS).

The degree to which each ion contributes to the total conductivity can be determined by combining the conductivity measurements with self-diffusion measurements obtained by pulsed field gradient nuclear magnetic resonance (PFG NMR) methods. Furthermore the presence of ion pairing or aggregation can be ascertained by direct comparison between the NMR-predicted and EIS-measured conductivity.

In this work, the PFG NMR stimulated echo sequence was used to measure the self-diffusion coefficients of the IL cation, Li+, and anion via 1H, 7Li and 19F, respectively, in the IL and ionogel with a concentration of 1M LiTFSI, at variable temperature covering the 0o – 100oC range. Two main confinement effects of all mobile ions in the ionogel are observed (i) a reduction in self-diffusion values of all ions compared to the pure IL; (ii) the presence of a relatively immobile fraction of the ions. Interestingly the effective Li transference numbers defined as D(Li)/[D(Li) + D(BMIM) + D(TFSI)] in the liquid electrolyte and the and ionogel are comparable, with a value of approximately 0.20.
Graphene-based materials with different morphologies and structures as interlayers for high-performance lithium-sulfur batteries
Authors: Kaenket Surasak , Chiochan Poramane , Phattharasupakun Nutthaphon , Wutthiprom Juthaporn , Limtrakul Jumras , Sawangphruk Montree
Published: February 2020

Lithium-sulfur batteries have attracted much attention for energy storage. However, the shuttle effect causes the poor cycling performance. In this study, we applied a carbon-based interlayer to trap polysulfide to reduce shuttle effect. The carbon-based materials including 3D reduced graphene oxide aerogel, 3D N-doped reduced graphene oxide aerogel, and 2D reduced graphene oxide. The materials were coated on one side of carboxylate-modified carbon fiber paper. The effect of the assemble direction of the coated materials facing in and out of the cathode were investigated. The results showed that the interlayer with 3D N-doped reduced graphene oxide aerogel exhibits superior performance and stability. In addition, the coated material placed face-to-face the cathode can improve the battery performance as compared to another direction.
Study on the Interface between NCM Layered Cathodes and Sulfide-Based Solid Electrolytes in All-Solid-State Batteries
Authors: Yun Bin-Na , Kim Hyoungchul , Jung Hun-Gi
Published: February 2020

Since the lithium-ion secondary batteries (LIBs) based on the LiCoO2 cathode materials, carbon based anode materials and organic liquid electrolyte have been commercialized, LIBs have been applied as power source for electric or hybrid vehicles beyond small IT applications. [1,2] As used in the large-scale energy storage devices, the safety of LIBs has given rise to more important issue. Therefore, the all-solid-state-batteries (ASSBs) with non-flammable inorganic solid electrolyte are one of the promising candidates.[3,4] Among the solid electrolyte materials, the sulfide-based solid electrolytes are widely used due to higher Li-ion conductivity and their soft property. Nevertheless, the ASSBs have been yet difficult to operate with the long cycle life and high current density despite the use of high Li-ion conducting solid electrolyte owing to the interfacial resistance and insufficient electrochemically active area. [5,6] Therefore, it is important to understand the interfacial characterization of solid-solid interface, especially the cathode and solid electrolyte in the composite cathode of ASSBs. Generally, the cathode materials and sulfide-based solid electrolytes have shown the large interfacial resistance from the space-charge layer and thus, as an effective approach to improve the electrochemical performance of ASSBs, the interfacial modifications for the cathode material by coating of LiNbO3, Li4Ti5O12, LiTaO3, and Li2O-SiO2 have been reported in previous studies. [5-7]

Herein, the detailed microscopic observation and structural analysis for the interface between Li(Ni0.6Co0.2Mn0.2)O2 (NCM622) layered cathode materials and sulfide-based solid electrolyte are carried out and the comparison with pristine NCM622 and LiNbO3-coated NCM622 is also depicted. For this study, transmission electron microscopy (TEM) and energy dispersive X-ray spectroscopy (EDS) analysis have been mainly used. For further investigations, the electrochemical impedance spectroscopy and charge-discharge performance of the all-solid-state batteries using pristine and LiNbO3-coated NCM622 were demonstrated.

References

[1] J.B. GoodenoughAuthor Vitae, K.S. ParkAuthor VitaeAuthor VitaeAuthor VitaeAuthor Vitae, J. Am. Chem. Soc., 4 (2013) 1167-1176.

[2] J.-Y. Hwang, S.-T. Myung, Y. K. Sun, Chem. Soc. Rev, 46 (2017) 3529−3614.

[3] Y. Ito, M. Otoyama, A. Hayashi, T. Ohtomo, M. Tatsumisago, Journal of Power Sources, 360 (2017) 328-335.

[4] N. Kamaya, K.Homma, Y.Yamakawa, M.Hirayama, R. Kanno. M. Yonemura, T. Kamiyama, Y. Kato, S. Hama, K. Kawamoto, A. Mitsui, Nat. Mater., 10 (2011), 628−686.

[5] N. Ohta, K. Takada, I. Sakaguchi, L. Zhang, R. Ma, k. Fukuda, M. Osada, T. Sasaki, Electrochem. Commun., 9 (2007), 1486-1490.

[6] Y. Seino, T. Ota, K. Takada, Journal of Power Sources, 196 (2011) 6488-6492.

[7] A. Sakuda, H. Kitaura, A. Hayashi, K. Tadanaga, M. Tatsumisago, Electrochem. Solid-state Lett. 11 (2007) A1-A3
Empirical Investigations of Micro-Pattern Morphology Effect on Lithium Metal Anodes
Authors: Ahn Jinhyeok , Jang Eun Kwang , Im Jinsol , Cho Kuk Young
Published: February 2020

Lithium ion batteries (LIBs) with higher capacity, longer life span, and improved safety have been demanded for many applications such as electric vehicles and grid-level energy storage systems. Lithium metal anode, among various electrode materials, is often regarded as the “Holy grail” electrode because of its high theoretical capacity (3860 mAhg-1) and the lowest electrochemical potential (-3.040V vs. standard hydrogen electrode).Nevertheless, there are difficulty in using lithium metal as anode due to intrinsic problems such as unstable solid electrolyte interphase (SEI) and uncontrolled lithium dendrite growth which induce poor safety, low coulombic efficiency, and short span life of batteries. Recently, it was reported that micro-patterned lithium metal anodes can suppress the dendrite growth during lithium plating/stripping. In this work, we fabricated different shapes of pattern on lithium metal anode. We also investigated the behavior of lithium dendrite growth from different pattern morphology during lithium plating and stripping process.
Porous Sb-Si-C Composite As a High-Performance Anode Material for Lithium Ion Batteries
Authors: Seo Hyungeun , Kim Jae-Hun
Published: February 2020

Recently, with increasing use of mobile electronic devices and electric vehicles, demand for electrical energy storage devices is greatly rising. Among them, lithium ion batteries (LIBs) are one of the most attractive devices because of their reasonable cost and energy density. To meet the consumer demand for energy density, high-capacity electrode materials should be developed. Currently, carbonaceous materials such as graphite are widely used in anodes and however, its capacity is limited due to the use of intercalation chemistry (theoretical capacity of graphite: 372 mAh g–1). To increase the capacity of an anode, Li-alloy type materials have been intensively examined. For example, Si has the theoretical capacity of 3580 mAh g–1 for Li15Si4 phase, which is the final phase of electrochemical lithiation. However, the Li-alloying type materials have a problem of cycle performance. When Li ions are inserted and extracted during cycling, the active materials suffer from huge volume expansion and shrinkage (100~400 %). The volume changes cause the mechanical degradation of the active materials and the material can be separated from the current collectors. As a result, the cycle performance of the electrodes is deteriorated. To solve the problem, lots of researchers have tried to prepare composite materials by adopting diverse methods. For instance, composite materials including inactive phases were prepared to alleviate the volume change. In this study, we prepared Sb-Si-C composites as high-capacity anode materials. Antimony (Sb) is considered one of the candidates as Li-alloy type active material and it has the theoretical capacity of 660 mAh g–1 for the Li3Sb phase. To obtain high-capacity and stable cycling stability, porous Sb-Si-C composites were synthesized by high energy mechanical milling and etching process. First, antimony oxide (Sb2O3), magnesium silicide (Mg2Si), and a carbon source were ball-milled. During the milling process, Sb2O3 was reduced to Sb by Mg and the formed MgO phase was removed by a solution etching process. Finally, the porous Sb-Si-C composite was prepared, which was evaluated as LIB anode materials.
Understanding the Role of Solvent and Added Water on the Effectiveness of Lithium Iodide As a Redox Mediator in Lithium Oxygen Batteries
Authors: Leverick Graham , Tulodziecki Michal , Katayama Yu , Tatara Ryoichi , Feng Shuting , Bardé Fanny , Shao-Horn Yang
Published: February 2020

Lithium iodide has been widely studied as a soluble redox mediator for lithium oxygen batteries in order to help promote more effective charging. Despite this research effort, ambiguities exist regarding the effectiveness of lithium iodide as a redox mediator. In a recent work, we have helped explain how lithium iodide influences the product formed during discharge; shifting from Li2O2, to LiOH, to LiOH-H2O and LiOOH-H2O depending on the amount and chemical environment of water present in the electrolyte. In this work, we provided a detailed framework for understanding how these various discharge products can be oxidized during charge based on solvent properties as well as the amount of water present. The importance of differing interactions between iodide, triioidide and iodine with glyme-based electrolytes with added water is discussed and a number of important behavior transitions at differing water concentrations are uncovered.

Figure 1