bluuebunny/crossref_metadata_2025 huggingface dataset:
Carbon Nanotubes Derived from Plastic Waste- a New Wave of Materials for Circular Economy
Authors: Lisak Grzegorz , Giannis Apostolos , Ahamed Ashiq , Moo James Guo Sheng , Veksha Andrei , Ge Liya , Weechachanchai Piyarat
Published: February 2020

Large amounts of plastic waste are generated worldwide. Owing to the lack of profitable solutions, the recycling rates for waste plastics are low. A new approach is required to convert mixed plastics into valuable products with potential monetary benefits to encourage waste collection and recovery, thus increasing circular economy concepts in waste management.

This study focuses on the development of carbon based materials, such as carbon nanotubes (CNTs) from plastic waste (Fig. 1) containing high (H-PET) and low PET (L-PET) content and their subsequent application as materials for electrodes and the use in various analytical and process engineering systems.

The plastic-derived CNTs were evaluated as electrocatalysts for hydrogen evolution (HER) and oxygen reduction reaction (ORR). The results from HER and ORR study were found comparable or better to the ones using commercial CNTs. The plastic waste derived CNTs were also evaluated as electrodes in various analytical applications, e.g. support and solid contact for ion-selective electrodes in potentiometry and detection of analytes with increased sensitivity in voltammetry. The results were compared to commercially available electrodes and materials derived from pure feedstock. Life cycle assessment (LCA) was conducted in order to identify the environmental impact and benefits of using waste over pure feedstock derived carbon materials in analytical applications. The results indicate that waste derived material perform equally well in analytical applications as the ones derived from pure feedstock. Furthermore, LCA indicates that the use of waste derived materials result in much lower environmental impacts compared to the pure feedstock derived carbon materials.

This study strongly encourages the use of waste derived carbon materials in order to increase the circular economy concepts and decrease environmental impacts connected to material development and the use of materials in various applications.

Fig. 1. Plastic waste derived CNTs.

Figure 1
A Novel Si/C Composite as a High Capacity Anode Material for Lithium-ion Batteries
Authors: Jeehee Lee , Joonsup Kim , Sangjin Kim , Cho Jaephil , Namhyeong Kim
Published: February 2020

Silicon based electrode materials for Li-ion battery have attracted great attention due to the high theoretical capacity of 4212 mAh/g (3.75 moles of Li per mole of Si) compared to graphite (1 mol Li per 6 mol C) used in commercial LIBs. Unfortunately, practical applications of silicon as an anode material exhibit the huge volume change (>300%) during the alloying / dealloying process with Li, which would result in the loss of electrical conductivity, dramatic pulverization of silicon, and consequently a rapid capacity fading in the cycling. To alleviate this problem, silicon nanosized or nanostructures materials have been suggested, which can increase the transport of electron and lithium ion and reduce mechanical stress during cycling, resulting in improved electrochemical performance. Among these nanostructures, the combination with carbon is becoming attractive and important material because it improves the electric conductivity and plays a role of a buffer of volume expansion.

In this research, a novel composite electrode material consisting of nanocrystalline silicon and porous graphite has been developed as an anode candidate for LIB. Nanocrystalline silicon was coated onto porous graphite via chemical vapor decomposition of SiH4 gas and subsequently pitch coating was carried out, which is known for a good method for preventing the natural oxidation of silicon layer and improving capacity.

We analyzed electrochemical properties of blended anode with graphite and nanocrystalline silicon­-porous graphite composite material. The capacity retention of the blending anode for nanocrystalline silicon­-porous graphite is 96% after 50 cycles with high coulombic efficiency of 90.1%, which is improved electrochemical performance compared with silicon non-porous graphite composite anode. Especially, the nanocrystalline silicon­-porous graphite composite material has lower expansion of electrode, comparing with silicon non-porous graphite composite material. The expansion of the nanocrystalline silicon­-porous graphite composite electrode is 42% after 1 cycle, while the expansion of the silicon non-porous graphite composite is 62% after 1 cycle. These improvements are attributed to the porous carbon shell, which reduces the cell expansion, prevents rupture of electrical path, stabilize the cycle performance.
(Plenary) Challenge for Innovation of Li-S Battery System
Authors: Sakaebe Hikari
Published: February 2020

Policy recommendations of the electrification of the vehicles have been issued all over the world in these years. Energy density is one of the important keywords for realizing such policies. Several novel systems have been investigated, and Li-S system is quite promising among them. Leading research organizations and start-up companies have manufactured the trial prototype Li-S cell with energy density of 300-400 Wh/kg. And Li-S batteries application is not limited to vehicles.

We have tried to innovate the conventional Li-S battery using metal polysulfides like a-TiS4
1,2, Li8FeS5
3, 4, VS4
5, and so on in RISING2 (Research and Development Initiative for Scientific Innovation of New Generation Batteries 2) project. Sulfur is connected to metal atom and dissolution of Li polysulfides into the electrolyte was greatly suppressed. Quite recently 8 Ah cell was constructed and energy density of more than 310 Wh/kg was confirmed. Project target is to confirm 500 Wh/kg by prototype cell for innovative batteries in the end of FY2020. In the presentation, RISING2 activity, state of the art of the Li-S and our recent progress will be introduced.

Acknowledgement

This work was financially supported by RISING2 project by NEDO and METI.

References

1. A. Sakuda, T. Takeuchi, H. Sakaebe, et al., Electrochem. Commun., 31 (2013) 71

2. A. Sakuda, H. Sakaebe, T. Takeuchi, et al., J. Am. Chem. Soc., 139 (2017) 8796.

3. T. Takeuchi, H. Sakaebe, et al., J. Electrochem. Soc., 162 (2015) A1745.

4. T. Takeuchi, H, Sakaebe, et al., Solid State Ionics, 320 (2018), 378.

5. K. Koganei, T. Takeuchi, H. Sakaebe, et al., Solid State Ionics, 323 (2018) 32.
(Invited) Perspectives and Challenges of Next Generation Automotive Li-Ion Materials and Cells
Authors: Paschos Odysseas
Published: February 2020

The development of e-mobility is at a tipping point with increasingly optimistic forecasts for the future market share of electric vehicles. Nonetheless, for electric vehicles to achieve mass-market penetration, a further improvement in the ratio between driving range and costs is mandatory. Different strategies are considered to increase electric range, including the optimization of battery pack, cell, and electrode. However the largest impact on energy density could be realized through the introduction of novel cathode and anode materials. There are a number of electrode materials currently in the research or development stage. Nevertheless, only a few of them have chances to meet automotive requirements, particularly in terms of lifetime and safety. Considerable improvements in these respects are still required, before a possible industrialization of the new generations of batteries for automotive application can be envisaged. In parallel, more revolutionary concepts based on post-lithium full-solid-state systems are evolving and could offer an even larger improvement potential.

This presentation will outline the potential and limits of present material concepts from a car manufacturer point of view. In particular, it will address open issues to be solved in the future development of electric energy storage technologies for automotive applications.
(Invited) Study of the Safety of Fresh and Aged Lithium-Ion Cells and Modules
Authors: Jeevarajan Judith A. , Mukherjee Partha P. , Juarez-Robles Daniel
Published: February 2020

Lithium-ion batteries are more commonly used today in a variety of applications from portable power to automotive and stationary energy storage. Due to the high cost of lithium-ion batteries and the fact that these batteries can perform really well even after 20% capacity loss, the batteries used in automotive applications are being considered for reuse in stationary energy storage installations. However, it is well known that although these types of second use installations have been initiated, very little has been understood regarding any changes that may occur with respect to the safety of these once-used or aged cells and batteries. The current study included studying single cells as well as modules to understand the cycle life trends as well as safety trends. Under cycle life testing of the cells and modules, two voltage ranges were studied and a set of cells were also subjected to HEV profiles at three different temperatures. Safety tests (overcharge and external short) were carried out on fresh and cycled cells and modules. Destructive physical examination with SEM and EDS analysis provided more insight into the physical and chemical changes that occur inside the cells under test. The results of this extensive study will be provided in this presentation.
(Invited) Progress on Hybrid Gel Polymer Electrolyte and Solid Electrolyte for Lithium Ion Batteries
Authors: Bascour Dominique , Braida Marc-David , Gloesener Daniel , Abusleme Julio A. , Rouault Helene , Besnard Gaelle , Mourzagh Djamel , Salomon Jérémie
Published: February 2020

Next generation batteries will have to provide high performances with reduced costs and safety advantage compared to the current lithium-ion products based on liquid electrolyte technology. For doing so, an appealing solution is to reformulate the electrolyte in a nonflammable form, such as a quasi solid state. Solvay, as a raw materials provider to battery manufacturers, develops components for next generation electrolyte materials.

The first part of the talk will focus on our Solgain™ solution. This technology, based on a hybrid organic/inorganic network combined with trapped liquid electrolyte, exhibits high ionic conductivity, high flexibility and good mechanical strength in addition to good electrochemical performances. Safety concern will be discussed and progress achieved so far on advanced Li-Ion batteries will be presented.

The second part of the talk will be focused toward solutions for Solid State Batteries. All-solid-state batteries using inorganic solid electrolytes and composite electrolytes are considered as promising energy storage systems because of their safety and long life. We will discuss the pathway and product development that Solvay has established to propose full solid state battery materials for future market needs.
(Invited) Anionic and Cationic Substitution to Control the Properties of Vanadium Fluorophosphates for Li and Na-Ion Batteries
Authors: Croguennec Laurence , Boivin Edouard , Nguyen Hoang Bao Long , Broux Thibault , Chotard Jean-Noël , Olchowka Jacob , Fauth François , Iadecola Antonella , Carlier Dany , Masquelier Christian
Published: February 2020

Optimized carbon-coated Na3V2(PO4)2F3 showed exceptional rate and electrochemical cycling capabilities, more than 4000 times at 1 C rate, as demonstrated by performance of hard carbon//Na3V2(PO4)2F3 18650 prototypes of 75 Wh kg−1.1 These attractive results, among others, attract a renewed interest in the field of Na-ion and Li-ion batteries for vanadium fluoride phosphates. The control of their electrochemical performance requires the careful tuning of the oxygen and thus vanadyle-type defects’ concentration in these materials. Indeed, the competition between the ionic V3+−F bond and the covalent V4+=O bond has a major effect on the structure of the pristine materials, and thus on the phase diagram and redox mechanisms involved upon their cycling in batteries.

It will be illustrated for series of LiVPO4F1-yOy
2,3 and Na3V2-xMx(PO4)2F3-yOy
1, 4-6 phases combining mainly Synchrotron X-ray diffraction and spectroscopy studies. Original, probably firstly unexpected, crystal chemistry and redox activity will be discussed.

Acknowledgements:

The authors thank the European Union’s Horizon 2020 Research and Innovation Program under grant agreement No 646433-NAIADES, the French National Research Agency (STORE-EX Labex Project ANR-10-LABX-76-01, HIPOLITE Progelec Project ANR-12-PRGE-0005-02 and SODIUM Descartes Project ANR-13-RESC-0001-02), and the French RS2E and European ALISTORE-ERI networks for funding.

References

T. Broux, F. Fauth, N. Hall, Y. Chatillon, M. Bianchini, T. Bamine, J.-B. Leriche, E. Suard, D. Carlier, Y. Reynier, L. Simonin, C. Masquelier, and L. Croguennec - Small Methods
2018, 1800215-1800226

E. Boivin, R. David, J.-N. Chotard, T. Bamine, A. Iadecola, L. Bourgeois, E. Suard, F. Fauth, D. Carlier, C. Masquelier, and L. Croguennec - Chemistry of Materials
2018, 30 (16), 5682-5693

E. Boivin et al., submitted

T. Broux, T. Bamine, F. Fauth, L. Simonelli, W. Olszewski, C. Marini, M. Ménétrier, D. Carlier, C. Masquelier, and L. Croguennec - Chemistry of Materials
2016, 28(21), 7683-7692

T. Broux, T. Bamine, L. Simonelli, L. Stievano, F. Fauth, M. Ménétrier, D. Carlier, C. Masquelier, and L. Croguennec - Journal of Physical Chemistry C
2017, 121(8), 4103-4111

H. B. L. Nguyen et al., submitted
(Invited) Can a “Battery” Only be Used as a “Battery” or Can We Do More?
Authors: Liu Junnan , Wang Sunny , Goonetilleke Damian , Andersen Henrik L , Al Bahri Othman K , Sharma Neeraj
Published: February 2020

Electrodes in batteries undergo a variety of changes during function. These include, but are not limited to intercalation, alloying and conversion reactions, evolution of the oxidation state of elements, crystal structures and the particle size (and distribution). Ideally minimal or controlled structural, morphological and macroscopic changes are desired for long term rechargeable battery function, and indeed many electrodes undergo transitions that are both highly reversible and irreversible. Furthermore, a variety of tools exist to probe these changes both in an in situ/operando and ex situ manner, e.g. Raman and NMR spectroscopy, X-ray, electron and neutron diffraction, to name a few techniques.

This presentation will detail two inter-related but unconventional aspects of research recently performed by our group.

We have been working towards using batteries or electrochemical cells as part of a synthetic strategy, whereby the changes induced by electrochemical reactions are purposefully used to generate new phases. These new phases are likely feature new properties and possibly new functionalities thus new applications. The energy storage aspects of the battery are replaced with the synthetic flexibility provided by applying controlled amounts of charge, for controlled amounts of time and being able to visualise changes using various in situ methods.

We have coined the term electrochemically activated solid state synthesis, whereby an electrode reacted in an electrochemical cell is subsequently extracted and heated resulting in the generation of a range of new or metastable phases, most of which have not been previously reported. This has been demonstrated for materials within the Ta1-x­NbxVO5 and Sc2W3-xMoxO12 families of electrodes used in Li, Na and K-based cells. A multitude of phase transitions are found with thermal treatments approximately at the onset of the decomposition of the binder used in the electrode. The talk will highlight the electrode preparation parameter space that can result in the generation of new phases, the identification of the phases and preliminary development of the mechanistic model associated with the synthetic strategy.

The second part of this talk will detail our recent investigation into solar batteries, where an electrode is able to both generate photocurrent and store charge carriers with exposure to light. We detail a new in situ electrochemical cell used to verify structural evolution (charge storage) during photo-irradiation of a MoO3 electrode providing direct experimental evidence for this process.

The culmination of these ideas allows batteries to be more than batteries, or possibly more appropriately it allows electrodes to have multiple functions in electrochemical cells.
(Keynote) Polyanionic Compounds for K-Ion Batteries
Authors: Hosaka Tomooki , Shimamura Tomoaki , Kubota Kei , Komaba Shinichi
Published: February 2020

We reported the high working voltage of K-ion battery (KIB) comparable to Li-ion and higher than Na-ion thanks to the standard potential of potassium is lower than those of lithium and sodium in non-aqueous electrolyte [1,2]. In 2015, our group reported graphite negative electrode delivering 250 mAh g-1 or higher with excellent reversibility [1]. Furthermore, a Prussian blue analogue (PBA) of K2Mn[Fe(CN)6] demonstrated highly reversible potassium insertion/extraction and 4 V operation, realizing a 4 V-class K2Mn[Fe(CN)6]/graphite full cell [3]. The previous studies revealed that a three-dimensional open framework structure of PBAs is suitable for insertion/extraction of large K+ ion. Addition to the PBAs, polyanionic compounds are potential positive electrode materials for KIBs due to their open framework structure and inductive effect. In this talk, our recent studies on potassium insertion into various polyanionic compounds, such as heterosite FePO4, KFePO4, KMnPO4, K2FeP2O7, K2MnP2O7, KVPO4F, KVOPO4, monoclinic KFeSO4F, and orthorhombic KFeSO4F (o-KFeSO4F) [4,5], will be presented to give a perspective of potassium insertion material design.

Because K+ ion is too large to occupy the octahedral site in heterosite FePO4 prepared from olivine-type LiFePO4, the crystallinity of heterosite FePO4 significantly decreases after potassium insertion. On the other hand, KVPO4F, KVOPO4, and o-KFeSO4F possess the KTiOPO4-type structure providing large channels to diffuse K+ ion and show the reversible potassium insertion/extraction properties and excellent rate performance. These results indicate that the crystal structure plays a key factor for reversible potassium insertion and rate performance. Moreover, the average discharge voltage of KVPO4F and KVOPO4 is as high as 4 V in a K half-cell. That of o-KFeSO4F is 3.6 V, which is notably high redox potential of Fe2+/Fe3+ due to the strong inductive effect of SO4
2- and F- on the Fe2+/3+ couple. The cycling stability of these high-voltage electrode materials is highly improved by using highly concentrated potassium salt solutions [6]. From these results, we will present our future insight into electrochemical potassium insertion chemistry for high voltage battery applications.

References

[1] S. Komaba et al., Electrochem. Commun., 60, 172 (2015).

[2] K. Kubota, T. Hosaka, S. Komaba et al., Chem. Rec., 18, 459 (2018).

[3] X. Bie, K. Kubota, S. Komaba et al., J.
Mater. Chem. A, 5, 4325 (2017).

[4] K. Chihara, S. Komaba et al., Chem. Commun.,
53, 5208–5211 (2017).

[5] T. Hosaka, T. Shimamura, S. Komaba et al., Chem. Rec., in-press

[6] T. Hosaka, Kei Kubota, S. Komaba et al., Chem. Commun., 54, 8387 (2018).
(Invited) New Approaches for Materials and Energy Sustainability
Authors: Chen Zheng
Published: February 2020

Materials sustainability has becoming an urgent issue in the rapidly growing lithium-ion batteries (LIBs) market. Among different cell chemist tries, layered oxide LiNixCoyMnzO2 (0<x,y,z<1, x+y+z=1) or NCM is the dominating cathode material in high energy LIBs, which have degradation issues after cycling due to the Li loss and phase changes. Directly resolving these issues to generate new cathodes can not only reduce the high cost but also prevent environmental pollution from disposal of used LIBs. However, currently there is no effective approach to tackle this challenge. In this talk, we demonstrate the successful regeneration of degraded NCM cathodes using a novel particle-to-particle approach. Using non-destructive methods, nearly ideal stoichiometry, low cation mixing and high phase purity were achieved in the regenerated NCM particles, which offer high specific capacity, cycling stability and rate capability reaching pristine materials. Our work represents a simple yet efficient approach to directly regenerate high-performance NCM cathodes with distinct advantages over traditional hydrometallurgical methods and builds an important foundation for the sustainable manufacturing of energy materials.
(Plenary) Solid State Li-Ion Batteries: Material Advances and a Reality Check
Authors: Nazar Linda F , Kaup Kavish , Zhou Laidong , Zhang Zhizhen , Park Kern Ho
Published: February 2020

The development of safe and high-performance all-solid-state batteries (ASSB) is contingent on creating fast ion conductors that combine high ionic conductivity with good ductility and chemical stability in a large voltage window, while – especially - mastering the interface of the solid electrolyte with the electrode materials. This presentation will examine ways to address these factors with new materials, while also shedding light on design concepts for ion conductivity.

The talk will cover an overview of the state-of-the art in the field, followed by a focus on recent findings in our laboratory concerning a) synthesis of thiophosphate-halide argyrodites, where very significant increases in conductivity above that of the parent Li6PS5Cl phase have been attained by both tuning composition and developing “clean” solution-engineering processing routes to these materials; b) creation of novel thiophosphate-halide and related structures that exhibit both ion conductivities above 1 mS/cm and good chemical stability; c) understanding the critical role that the anion framework plays in dictating ion conductivity using a combination of room/high temperature X-ray/neutron diffraction, NMR, and ab initio molecular dynamics simulations; d) examination of the interface of the solid state electrolytes at the positive and negative electrodes in practical ASSBs.
(Invited) Measuring and Defining Electrochemical Reactions of Transition Metal Oxides in Mg Electrolytes
Authors: Cabana Jordi
Published: February 2020

Electrochemical energy storage was an important enabler of the wireless revolution and it is touted as a key component of a society that shifts away from its dependence on fossil fuels. Li-ion batteries are the primary technology when high energy devices are required. However, despite their improved functionality over older systems (e.g. lead-acid car batteries), they do not quite yet meet the emerging energy demands in transportation and grid markets. This roadblock sparked interest in the development of batteries that utilize Mg2+ as ionic carrier. Theoretical predictions indicate that couples exist between a Mg metal negative electrode and oxide positive electrodes that could surpass the current practical limits of current devices. Among the candidate oxides, those showing a spinel structure have been predicted as the most suitable for the reversible intercalation of ions such as Mg2+ or even Ca2+ [1], the critical reaction in the positive electrode. However, experimental validation, while incipient [2], has not been fully achieved. In this talk, we will present the most up-to-date insight into the ability of spinel oxides to diffuse and reversibly intercalate Mg2+. In this task, the ability to synthesize particles at small dimensions is vital, as is the characterization of chemical and physical phenomena using a combination of tools providing information at different scales. We will rely on data from X-ray diffraction, spectroscopy and scattering, electron microscopy and nuclear magnetic resonance to probe the reactions that occur when spinel oxides are used as working electrodes in cells with electrolytes containing Mg2+. The rationale for the choice of techniques and the key pieces they provided to complete the picture will be discussed. Our ultimate aim in the talk will be to establish relationships between crystal-chemistry, charge carrier and outcomes of the electrochemical reaction.

Liu, M., et al.,
Energy Environ. Sci. 2015, 8, 964.

Kim, C. et al., Adv.
Mater. 2015, 27, 3377.
(Invited) Exploring the Impact of Mechanical Pressure on the Performance of Anode-Free Lithium Metal Cells
Authors: Louli Alexander J , Genovese Matthew , Weber Rochelle , Dahn Jeff R
Published: February 2020

Research on lithium metal batteries has made a resurgence in the quest to surpass the energy density of conventional lithium ion batteries. Many reports in the literature utilize Li-metal cells with significant excess lithium, thereby artificially inflating the cycling efficiency and cycle life of such cells since lost lithium inventory can be replaced from a vast reservoir. However, utilizing significant excess lithium can drastically reduce the energy density of Li-metal cells even below that of conventional Li-ion as shown in Figure 1; at 200% excess lithium, the theoretical volumetric capacity of Li of 2060 mAh/L becomes 687 mAh/L, lower than the volumetric capacity of graphite of 719 mAh/L. Clearly cells with significant excess lithium are not poised to succeed conventional lithium ion cells in delivering superior energy density. In contrast, anode-free cells do not utilize excess lithium and thus can deliver the maximum theoretical capacity of lithium metal. In an anode-free cell, the lithium ions stored in the positive electrode plate on a bare current collector during the first charge to form a lithium metal anode in-situ.1,2 As such, lithium metal is not required during the construction of anode-free cells, resulting in a cheaper, safer and more practical Li-metal cell.

In this work, we evaluate anode-free Li-metal pouch cells (NMC532||Cu) with operando pressure measurements constrained to different stack pressures between 75-2205 kPa with two different electrolytes, 1M LiPF6 fluoroethylene carbonate: diethyl carbonate (FEC:DEC 1:2) and 1M LiPF6 fluoroethylene carbonate:bis(2,2,2-trifluoroethyl) carbonate (FEC:TFEC 1:2). Increasing the initial average pressure from 75 to 2205 kPa was found to generally improve cycling performance, with the most significant benefits achieved up to 1205 kPa. Cells containing FEC:TFEC electrolyte exhibited a superior initial plating efficiency than FEC:DEC cells. The benefit of constraining cells containing FEC:TFEC electrolyte is shown in Figure 1. Although generally beneficial, we found that the effect of increased pressure on the performance of cells with different solvent systems was not equal, particularly at high pressures, indicating that the physical properties of the electrolyte play an important role in cells constrained to higher pressures between 1205 and 2205 kPa. This work presents anode-free cells which deliver a larger energy density than conventional Li-ion cells for 50 cycles.

Figure 1
Plane-Selective Coating of LiCoO2 Powders for Li-Ion Batteries
Authors: Kim Hanseul , Lee Kyu Tae
Published: February 2020

LiCoO2 is one of the most widely commercialized cathode materials for Li-ion batteries. Recently, LiCoO2 has been revisited to improve its reversible capacity by increasing the upper cut-off voltage to 4.55 V (vs. Li/Li+). However, LiCoO2 suffers from determental Co-dissolution and electrolyte decomposition at high voltages and high temperatures, resulting in poor electrochemical performance.[1,2] In this connection, various coated LiCoO2 powders have been investigated to reduce these irreversible surface reactions.[3]

Coated LiCoO2 powders are usually obtained via sol-gel synthesis, dry coating, and atomic layer deposition. These coating techniques are pursuing to uniform coating covering the whole surface of LiCoO2 powders. However, the full coverage of coating layers interrupts the charge-transfer of Li+ ions, resulting in the poor rate capability of LiCoO2. This implies that we can improve the rate performance of LiCoO2, if we are able to coat specific facets of LiCoO2 powders except for the charge-transfer planes.

In this presentation, we introduce, for the first time, a new plane-selective coating of LiCoO2. For example, we demonstrate that metal oxides coating layers are grown plane-selectively on the LiCoO2(001) surface. We show synthesis details for the plane-selective coating of LiCoO2. Scanning transmission electron microscopy (STEM) analysis was carried out with a high-angle annual dark field (HAADF) mode to observe the plane-selective coatings. The electrochemical performance of the plane-selectively coated LiCoO2 was better than that of the conventionally coated LiCoO2. Moreover, we discuss the origin of the plane-selective coating of LiCoO2.

References

[1] B. Xu, D. Qian, Z. Wang, Y. S. Meng, Materials Science and Engineering: R: Reports 2012, 73, 51

[2] W. Li, A. Dolocan, P. Oh, H. Celio, S. Park, J. Cho, A. Manthiram, Nat Commun 2017, 8, 14589

[3] Y.-K. Sun, C. S. Yoon, S.-T. Myung, I. Belharouak, K. Amine, Journal of The Electrochemical Society 2009, 156, A1005
Towards High-Voltage Sodium-Ion Batteries Based on Aqueous Electrolytes
Authors: Kühnel Ruben-Simon , Reber David , Battaglia Corsin
Published: February 2020

Water-in-salt electrolytes enable the operation of batteries at higher voltage than previously possible with conventional aqueous electrolytes.[1,2] High-voltage aqueous batteries are potential candidates for stationary electricity storage where low total cost of ownership is more important than high energy density.

To date, most water-in-salt studies have focused on enabling aqueous lithium-ion batteries. However, considering the high salt content of water-in-salt electrolytes, sodium-ion batteries appear particularly interesting for this approach as sodium salts are typically significantly less expensive than their lithium analogues, but typically exhibit insufficient solubility due to the lower charge density of Na+ compared to Li+.[3]

Recently, we discovered that NaFSI displays very high solubility in water, enabling a wide electrochemical stability window.[4] Although S-F bonds present in the FSI anion are known to be relatively weak and hence make FSI prone to hydrolysis, we demonstrate a 2 V class NaTi2(PO4)3/Na3(VOPO4)2F cell with an excellent capacity retention of 85% after 500 cycles at 1C. To the best of our knowledge, the specific energy of our cell of 65 Wh/kg (based on the active masses of both electrodes) is the highest reported to date for an aqueous sodium-ion battery. Using strategies to prevent electrolyte crystallization, we also demonstrate stable cycling at temperatures as low as -10 °C.

[1] L. Suo, O. Borodin, T. Gao, M. Olguin, J. Ho, X. Fan, C. Luo, C. Wang, K. Xu, Science 350 (2015) 938.

[2] Y. Yamada, K. Usui, K. Sodeyama, S. Ko, Y. Tateyama, A. Yamada, Nat. Energy 1 (2016) 16129.

[3] D. Reber, R.-S. Kühnel, C. Battaglia, Sustainable Energy Fuels 1 (2017) 2155.

[4] R.-S. Kühnel, D. Reber, C. Battaglia, ACS Energy Lett. 2 (2017) 2005.
Casein As a Novel Binder for Silicon-Based Electrodes for Li-Ion Batteries
Authors: Chandrasiri Dilni Kaveendi , Lucht Brett L.
Published: February 2020

High capacity electrode material has been studied over the years due to the constant demand for high energy density applications in li ion batteries. Among others, silicon has been considered a more promising candidate for its high theoretical capacity of ~ 3600 mAh/g, abundant resources, low cost and low toxicity. However, silicon-based electrodes face rapid degradation due to the extensive volume variation (~300%) in the charge discharge process. Binders used in the electrode fabrication plays a crucial role in these high-performance electrodes since it can reduce the mechanical fracture in the cycling process.

Utilization of polymeric material as binders to hold the active material has been the most common approach used in the li ion battery electrode preparation. Recent studies carried out by Nguyen et. al have shown the use of small molecular carboxylic acids as binders which showed an improvement in the cell performance for silicon electrodes. In this study we introduce a cheap and environmentally friendly alternative that could be used as a non-polymeric binder for silicon electrodes. Further, the electrode preparation can be done in water medium which reduces the introduction of toxic organic solvents such as NMP to the environment. Casein is a milk protein found in bovine milk rich in amine groups and carboxylic acid groups which can form bonds with the silanol groups in silicon. A comparative study conducted between PVDF and Casein as binders have shown that when casein was used as binder, it shows better performance compared to PVDF. It has 12% higher capacity retention compared to PVDF with a 2200 mAh/g capacity after 50 cycles. Surface morphology and Solid electrolyte interface was analyzed using electron microscopy techniques and spectroscopic methods and the results will be discussed.
Stable Li Metal Anode through Designed Solution Chemistry
Authors: Liu Haodong , Zhou Hongyao , Liu Ping
Published: February 2020

Lithium metal is being extensively studied as an anode to replace graphite due to its high capacity and the lowest negative electrochemical potential. Current research focus is to mitigate lithium dendrite growth and to increase coulomb efficiency during electrochemical cycling by using various surface coatings, electrolyte additives.1, 2 In addition, a 3D host can be beneficial due to the reduced volume change.3 We have recently focused on designing novel electrolyte solution chemistry that enables dendrite free Li metal cycling. The structure, physical and chemical properties of the designed electrolyte solution are well in accordance with the quantum chemistry calculations. The XPS analysis of the SEI (solid electrolyte interface) components on the Li metal surface reveals that a LiF rich protection layer forms. As a result, a high average coulombic efficiency of 99.4% has been achieved at 0.5 mA cm-2 for 1 mAh cm-2 over 900 cycles. Even at a high current density of 10 mA cm-2, the coulombic efficiency of Li metal in this novel electrolyte is above 98.5%. A Li metal full cell with PANS (Poly(acrylonitrile) Sulfur) as cathode realizes a capacity retention of >98% over 900 cycles. This study offers a promising approach to enable highly stable Li metal battery applications.

Acknowledgements

This work was supported by the Office of Vehicle Technologies of the U.S. Department of Energy through the Advanced Battery Materials Research Program (Battery 500 Consortium) under Contract DE-EE0007764. Part of the work used the UCSD-MTI Battery Fabrication Facility and the UCSD-Arbin Battery Testing Facility.

H. Liu, X. Wang, H. Zhou, H.-D. Lim, X. Xing, Q. Yan, Y. S. Meng and P. Liu, ACS Applied Energy Materials, 2018, DOI: 10.1021/acsaem.8b00348.

H. Liu, H. Zhou, B.-S. Lee, X. Xing, M. Gonzalez and P. Liu, Acs Applied Materials & Interfaces, 2017, 9, 30635-30642.

H. Liu, X. Yue, X. Xing, Q. Yan, J. Huang, V. Petrova, H. Zhou and P. Liu, Energy Storage Materials, 2018, DOI: https://doi.org/10.1016/j.ensm.2018.09.021.
Pushing the Limit of Layered Cathodes for High-Energy Density, Long-Term Cycling, and High Thermal Stability Rechargeable Li Ion Batteries
Authors: Kim Un-Hyuck , Nam Gyeong Won , Yoon Dae Ro , Sun Yang-Kook
Published: February 2020

Development of advanced high energy density lithium ion batteries is important for promoting electromobility. Making electric vehicles attractive and competitive compared to conventional automobiles depends on the availability of reliable, safe, high power, and highly energetic batteries whose components are abundant and cost effective. Nickel rich Li[NixCoyMn1-x-y]O2 layered cathode materials (x > 0.5) are of interest because they can provide very high specific capacity without pushing charging potentials to levels that oxidize the electrolyte solutions. However, these cathode materials suffer from stability problems. We discovered that doping these materials with tungsten (1 mol%) remarkably increases their stability due to a partial layered to cubic (rock salt) phase transition. We demonstrate herein highly stable Li ion battery prototypes consisting of tungsten-stabilized Ni rich cathode materials (x > 0.9) with specific capacities > 220 mAh g-1. This development can increase the energy density of Li ion batteries more than 30% above the state of the art without compromising durability.

R. Dahn, U. von Sacken, M. W. Juzkow, and H. Al-Janaby, J. Electrochem. Soc., 1991, 138, 2207.

-U. Woo, B.-C. Park, C. S. Yoon, S.-T. Myung, J. Prakash, and Y.-K. Sun, J. Electrochem. Soc., 2007, 154, A649.

H. Lee, C. S. Yoon, J.-Y. Hwang, S.-J. Kim. F. Maglia, P. Lamp, S.-T. Myung, and Y.-K. Sun, Energy Environ. Sci., 2016, 9, 2152.

Watanabe, M. Kinoshita, T. Hosokawa, K. Morigaki, and K. Nakura, J. Power Sources, 2014, 258, 210.
A Safe Potassium-Sulfur Battery Using a Potassium Polysulfide Catholyte and Metal-Free Anode
Authors: Hwang Jang-Yeon , Kim Hee Min , Sun Yang-Kook
Published: February 2020

An integral part of promoting the large-scale use of new renewable energy sources is the development of cost- effective energy storage technologies.1,2 Recently, potassium-ion batteries (KIBs) have attracted widespread interest as a low-cost, alternative energy storage medium to replace the widely used lithium-ion batteries (LIBs) because potassium has higher natural abundance (the reserve of potassium is close to that of Na in the Earth’s crust) and a lower standard redox potential than other metallic elements (E°(Li/Li+): -3.04 V; E°(K/K+): -2.93 V; E°(Ca/Ca2+): -2.87 V; E°(Na/Na+): -2.71 V; E°(Mg/Mg2+): -2.27 V versus the standard hydrogen redox potential).3

Room-temperature metal–sulfur batteries have attracted extensive interest due to their advantages, which include high theoretical capacities, high elemental abundances, low costs, and environmental friendliness.3 We proposed a different type of room-temperature K–S battery composed of a solution-phase potassium polysulfide (K2Sx) catholyte and a 3D freestanding carbon-nanotube-film (3D-FCN-flm) electrode.4 Based on the reversible conversion reactions, K2Sx (5 ≤ x ≤ 6) → K2S3 (discharge) → K2S5 (charge), the proposed K-S battery delivered a high discharge capacity of ∼400 mAh/g at 0.1 C-rate with stable cycle retention (94% after 20 cycles) and good rate capability up to 2 C-rate. In addition, instead of an explosive and highly reactive potassium metal electrode, a full cell consisting of an electrochemically potassium-impregnated hard carbon and the K2Sx (5 ≤ x ≤ 6) catholyte was constructed to demonstrate the feasibility of a safe K-S battery system free of metallic potassium.

References

J.-Y. Hwang, S.-T. Myung and Y.-K. Sun, Chem. Soc. Rev., 2017, 46, 3529–3614.

J.-Y. Hwang, J. Kim, T.-Y. Yu, S.-T. Myung, and Y.-K. Sun, Energy Environ. Sci., 2018,11, 2821-2827.

J.-Y. Hwang, S.-T. Myung, and Y.-K. Sun, Adv. Funct. Mater. 2018, 28, 1802938.

J.-Y. Hwang, H. M. Kim, C. S. Yoon, and Y.-K. Sun, ACS Energy Lett. 2018, 3, 540-541.
Mg-Doped Na3V2(PO4)2F3/C Cathodes for Sodium Ion Batteries
Authors: Puspitasari Diah Agustina , Lee Tai-Chou , Chang Jeng-Kuei
Published: February 2020

Lithium-ion batteries (LIBs) are competent energy storage devices that have been used for electronic devices. However, for large-scale applications, there are concerns about the cost and lithium reserves. The market requires batteries which have high energy density, high safety, low cost, and environmental benignity [1-2]. Recently, the sodium-ion batteries (SIBs) have received much attention because of their similar electrochemical properties with LIBs. Na3V2(PO4)2F3 has been developed as a cathode material for SIBs due to high voltage, high thermo-stability, and high capacity [3].

Na3V2(PO4)2F3/C (NVPF/C) with a NASICON structure has a Na+ intercalation potential of 3.76 V. However, the NVPF/C has a low electronic conductivity which hinders the capacities and rate capability. Carbon coating and particle size reduction can improve the electrochemical performance. In addition, this work use Mg2+ doping attempting to increase the bulk conductivity of NVPF. Na3V2-xMgx(PO4)2F3/C cathodes are successfully synthesized using a sol-gel method with citric acid as the reducing agent and carbon source. X-ray diffraction (XRD) analysis confirms that Mg has been doped into NVPF/C. The XRD peak shifts indicate a lattice contraction due to the smaller atomic size of Mg as compared to V. The Mg-doped NVPF/C cathodes show promising properties for SIB applications.

Reference:

[1] M. Arumugam and Y. Ya. Advance Energy Mater., 2018, (8), 1-11

[2] W. Feixiang, Z. Chenglong, C. Shuangqiang, L.Yaxiang, H. Yanglong, H. Yong-sheng, M. Joachim and Y. Yan, Material Today. doi.org/10.1016/j.mattod.2018.03.004, 2017

[3] Z. Liu, Y.-Y. Hu, M. T. Dunstan, H. Huo, X. Hao, H. Zou, G. Zhong, Y. Yang and C. P. Grey. Chem. Mater., 2014, (26), 2513–2521.
Improvement of High-Rate Discharging Performance of LiFePO4 Cathodes by Forming Micrometer-Sized through-Holed Electrode Structures with a Pico-Second Pulsed Laser
Authors: Matsumoto Futoshi , Tsuda Takashi , Ando Nobuo , Nakamura Susumu , Hayashi Narumi , Soma Naohiko , Tanabe Toyokazu , Ohsaka Takeo
Published: February 2020

Holing of lithium iron phosphate (LiFePO4, LFP) cathodes with a pico-second pulsed laser, in which the average hole diameter and hole opening rate were 20-30 mm and 1-2%, respectively, enabled to retain the high-rate discharging performance even in the LFP cathodes composed of the having the LFP layer with the thickness of over 40 mm on an aluminum current collector. The conventional and flat LFP cathode exhibited the degradation of discharge retention at the high-rate discharge because of the low utilization of LFP materials in the case of the thick cathode layer. On the other hand, in the case of “through-holed” and “non-through-holed” LFP cathodes, there can be a more efficient insertion/de-insertion of Li+ ions to/from the LFP materials through the holes formed in the LFP layer, resulting in retaining the high-rate charging/discharging performance even in thick LFP cathodes. The electrochemical impedance spectroscopy analysis confirmed that the formation of through-holes in the thick LFP layer is significantly effective to improve the high-rate discharging performance as a result of the decreased charge-transfer resistance of the LFP discharge process. The decrease in the charge-transfer resistance results from the increase in the area available in the LFP discharge process because the sidewalls of the holes can also take part in the Li+ ion transfer during the discharge process.

Figure 1
Microstructure Development of Full Concentration Gradient Li[Ni0.75Co0.10Mn0.15]O2 Cathode for Lithium-Ion Batteries
Authors: Kim Jae-Hyung , Kim Un-Hyuck , Park Kang-Joon , Sun Yang-Kook
Published: February 2020

Detailed analysis of the microstructural changes during lithiation of a full-concentration-gradient (FCG) cathode with an average composition of Li[Ni0.75Co0.10Mn0.15]O2 was performed starting from its hydroxide precursor, FCG [Ni0.75Co0.10Mn0.15](OH)2 prior to lithiation. Transmission electron microscopy (TEM) revealed that a unique rod-shaped primary particle morphology and radial crystallographic texture were present in the pre-lithiation stage. In addition, TEM detected a two-phase structure consisting of MnOOH and Ni(OH)2, and crystallographic twins of MnOOH on the Mn-rich precursor surface. The formation of numerous twins, driven by the lattice mismatch between MnOOH and Ni(OH)2, resulted in crenellated surfaces. Furthermore, the twins persisted in the lithiated cathode; however, their density decreased with increasing lithiation temperature. Cation disordering, which influences cathode performance, was observed to continuously decrease with increasing lithiation temperature with a minimum observed at 790 °C. Consequently, lithiation at 790 °C (for 10 h) produced optimal discharge capacity and cycling stability. Above 790 °C, an increase in cation disordering and excessive coarsening of the primary particles led to the deterioration of electrochemical properties. It is conjectured that the twins in the FCG cathode precursor promoted the optimal primary particle morphology by retarding the random coalescence of primary particles during lithiation, effectively preserving both the morphology and crystallographic texture of the precursor. Furthermore, the effects of the precursor microstructure and subsequent final primary particle morphology on the optimal lithiation schedule and cation disordering were determined.

Y.-K. Sun, S.-T. Myung, B.-C. Park, J. Prakash, I. Belharouak, K. Amine, Nat. Mater.
2009, 8, 320.

J. H. Lee, C. S. Yoon, J.-Y. Hwang, S.-J. Kim, F. Maglia, P. Lamp, S.-T. Myung, Y.-K. Sun, Energy Environ. Sci.
2016, 9, 2152.

U.-H. Kim, E.-J. Lee, C. S. Yoon, S.-T. Myung, Y.-K. Sun, Adv. Energy Mater.
2016, 6, 1601417.

C. S. Yoon, K.-J. Park, U.-H. Kim, K. H. Kang, H.-H. Ryu, Y.-K. Sun, Chem. Mater.
2017, 29, 10436.
Lithiation/Delithiation Behaviors of Electrode/Electrolyte Materials for Li Ion Batteries Viewing from Defect Reactions
Authors: Fung Kuan-Zong , Tsai Shu-Yi , Liu Chi-Yang , Chang Li-Fu , Huang Bo-Yuan
Published: February 2020

For functional materials used for lithium ion batteries, their electrochemical properties are highly dependent on their defect structures. For examples, the reversible capacity of layered cathode such as LiCoO2 is limited by its highly defective layered structure when state of charge greater than 50%. On the other hand, capacity of spinel or olivine cathodes show higher delithiation rate without noticeable phase change. Furthermore, with oxygen defects formed in Li2MnO3, the capacity of Li-rich layer-structured cathode formulated as xLi2MnO3-(1-x)LiMO2(M = Mn, Ni, Co, etc.) was able to provide high reversible capacity (>250 mAh/g) for Li-ion battery applications. Similarly, the zero-strain anode materials Li4Ti5O12 shows high interface polarization and low rate capability due to low electronic defects. Hopefully, the rate capability may be improved by introduction of more electronic defects on Ti cation sublattice.

In additions, the properties of solid state Li ion conductors for all-solid-state lithium batteries is strongly affected by their defect structures as well. Due to its better safety characteristics, solid-state lithium battery may use more reactive anode, such as Li. Thus, it is extremely crucial to find a stable solid electrolyte when the high-capacity Li anode is used. In our study, the stability of perovskite-based La0.50Li0.50TiO3, NASICON-based Al-doped LiTi2(PO4)3, and garnet-based Li7La3Zr2O12 against metallic Li were investigated. After La0.50Li0.50TiO3 reacted with Li, the electron injection accompanied by the incorporation (insertion) of Li ion into vacant cation sites was likely to take place. The apparent reduction of tetravalent Ti into trivalent Ti was observed in La0.50Li0.50TiO3. On the other hand, Al-doped LiTi2(PO4)3, and garnet-based Li7La3Zr2O12 are much more stable when Li anode is used. For these solid electrolytes, the difference in stability against metallic Li may be rationalized based on their defect structures and corresponding atomic arrangements.