bluuebunny/crossref_metadata_2025 huggingface dataset:
Advances in the Aqueous Processing of Ni-Rich Positive Electrodes
Authors: Radloff Sonja , Carbonari Gilberto , Scurtu Rares-George , Hölzle Markus , Wohlfahrt-Mehrens Margret
Published: November 2022

A sustainable and environmental friendly production process of the battery components is a crucial factor for a successful contribution of Li-ion batteries to a more sustainable energy supply. For carbon-based anodes the eco-friendly, water-based processing is already widely established, whereas the same procedure still poses several challenges for cathode materials, especially those with high Nickel content. One major challenge is the detrimental side-reaction of Ni-rich cathode active materials (CAM) with water, creating hydroxide and carbonate species which increase the pH of the paste to above 12. Consequently, the Al foil is corroded during the coating process. Therefore, it is essential to control the paste’s pH before casting the paste on the substrate Al foil. This step becomes more challenging the longer the electrode mixing and coating procedure takes. On top of this, a promising way of improving the aqueous-based processing is to identify a suitable water-based binder system to improve the electrochemical cycling stability.

We present the application of a variety of different water-based binders, all used in combination with carboxymethyl cellulose (CMC) as thickening agent. The paste pH is controlled by adding H3PO4. Electrodes with industry relevant areal capacities of up to 3 mAh/cm2 are electrochemically evaluated in full pouch cells. The long-term cycling stability determined with 1 C charge/discharge was highly dependent on the binder system. The best electrodes reached an excellent capacity retention of up to 88% after 1000 cycles. The NMP-based reference electrode reached 91%.

The investigation of the aged cells via post mortem analysis suggests that the main source of cell aging is the cathode electrode. According to scanning electron microscopy data, no stronger cracking of the secondary CAM particles and no enhanced dissolution of transition metals were observed for the aqueous cathodes. However, a stronger rise in charge-transfer impedance was observed for the aged, water-based cathodes. This suggests that the formation of a blocking surface layer is the major reason for a stronger performance decay with increasing cycle number.

Acknowledgment

The presented work was financially supported by the project DigiBattPro4.0 BW (3–4332.62-IPA/69) by the Ministry of Economic Affairs, Labour and Housing Baden-Württemberg and by the project DigiBattPro4.0 BMBF funded by the German federal ministry of education and research Baden-Württemberg (03XP0374D).
Degradation and Durability of Highly Ni-Rich Cathode Materials According to Dwell Times at the Charged State
Authors: Sun HoHyun , Allen Jan L
Published: November 2022

Unlike batteries in classical experimental settings, batteries in practical applications are generally not discharged immediately upon reaching a fully charged state but remain for a period of time before usage. Such a state is demanding on the cathode as much of the Ni-rich layered oxide degradation mechanisms occur at the deeply charged state. Here, we examine a Ni-rich cathode material (i.e., Li[Ni0.90Co0.05Mn0.05]O2) under conditions simulating real-use behavior of batteries and find that the addition of a short dwell period at the deeply charged state leads to substantial differences in cycling performance (89.4 % versus 37.5 % retention rates after 100 cycles, respectively). Furthermore, to overcome the rapid deterioration, Sb was used as a dopant to promote stability, especially at the grain boundaries regions, to suppress degradation at the cathode-electrolyte interface. The resulting cathode energy material (i.e., Li[Ni0.895Co0.05Mn0.05Sb0.05]O2) proved to be stable during extended periods at the charged state.

Figure 1
Ultrafine-Grained Ni-Rich Layered Cathode for High-Performance Li-Ion Batteries
Authors: Park Geon-Tae , Noh Tae-Chong , Sun Yang-Kook
Published: November 2022

Currently, Li-ion batteries (LIBs) are the main power source for electric vehicles (EVs) because of their high energy density, excellent rate performance, and long cycle life. However, even EVs that are powered by state-of-the-art LIBs are unable to meet the driving range offered by internal combustion engine vehicles (ICEVs), which is typically 600–800 km.1 The properties of LIBs are strongly related to the nature of positive electrodes (cathodes), and thus, the selection of appropriate cathodes is of paramount importance. Currently, Ni-rich layered LiMO2 (M = Ni, Co, Mn, and/or Al) compounds are considered ideal cathode materials for EV batteries because their high capacity enables EVs to achieve high mileage per charge. Although Ni-rich layered cathodes are advantageous in terms of energy density and material cost, in general, they have considerably decreased cycling lifetimes with inferior thermal stabilities, which hinder their commercialization. The inherent structural instability of Ni-enriched layered oxide cathodes, particularly in the deeply charged state, leads to a build-up of mechanical strain.2 The strain build-up causes the nucleation and propagation of microcracks, which enable electrolyte infiltration and accelerate structural deterioration, which has plagued attempts to stabilize the cycling performance of Ni-rich layered cathodes.3 In this study, we demonstrate that limiting the primary particle size of the cathode resolves the capacity fading problem as nano-sized primary particles effectively relieve the high internal strain associated with the phase transition near charge end and fracture-toughen the cathode. Particle size refinement, achieved by inhibiting the grain growth during lithiation through the introduction of a high-valence dopant, imparts the necessary mechanical toughness to counter the high internal strain associated with the phase transition near charge end. The Li[Ni0.95Co0.04Mn0.01]O2 cathode, whose microstructure is engineered to mitigate the mechanical instability of Ni-rich layered cathodes, represents a next-generation, high energy-density cathode with a long cycle life and fast charging capability.

Reference
s
:

[1] K. B. Naceur, Tracking Clean Energy Progress (International Energy Agency, 2016).

[2] H.-H. Ryu, K.-J. Park, C. S. Yoon and Y.-K. Sun, Chem. Mater. 30 (2018) 1155–1163.

[3] G. W. Nam, N.-Y. Park, K.-J. Park, J. Yang, J. Liu, C. S. Yoon, Y.-K. Sun, ACS Energy Lett. 4 (2019) 2995–3001.
Crystallographic Design of Intercalation Materials
Authors: Renuka Balakrishna Ananya
Published: November 2022

In this talk, I will share some of our ongoing work to enhance the lifespans of lithium battery materials. We recently demonstrated how film straining of intercalation electrodes can circumvent its structural degradation upon repeated cycling. While suppressing chemo-mechanical degradation has been a longstanding problem; our paper initiates a new line of research by using mechanical stress states to regulate the energy landscape in intercalation materials and to thus improve their lifespans [1]. In a more recent work, we draw inspiration from shape memory alloys to design microstructures that mitigate degradation in intercalation materials. We have developed a theoretical framework that predicts structural transformation pathways of intercalation materials and identifies candidate compounds that approximately satisfy geometric constraints to form shape-memory-like microstructures [2]. Overall, our research aims to establish a theoretical and computational framework to accelerate the discovery and development of energy-related materials.

References

[1] Zhang, D., Sheth, J., Sheldon, B.W., & Balakrishna, A.R. (2021). Film strains enhance the reversible cycling of intercalation electrodes. Journal of the Mechanics and Physics of Solids, Volume 155, 10455

[2] Balakrishna, A.R. (2022). Crystallographic design of intercalation materials. arXiv preprint arXiv:2204.04525, 2022
Influence of Cerium Oxide Coating on LiNi0.5Mn1.5O4 Microspheres As Cathode in High Performance Lithium-Ion Batteries
Authors: Qureshi Zawar Alam , Tariq Hanan Abdurehman , Shakoor Abdul , Kahraman Ramazan , Al-Qaradawi Siham
Published: November 2022

Cobalt-free LiNi0.5Mn1.5O4 (Lithium Nickel Manganese Oxide; LNMO) has attracted much attention as a cathode material due to its high operating voltage, high energy density, lower cost, and environmental friendliness. However, LNMO cathodes are currently suffering from poor cyclability, and capacity degradation at elevated temperatures and high voltages, greatly limiting their large-scale adaptation. To this end, we used a microwave-assisted chemical co-precipitation approach to manufacture pure LiNi0.5Mn1.5O4 (LNMO-P) and CeO2-coated LMNO (LNMO-Ce) microspheres. Cells with these cathodes were cycled between 4.9 V and 3.5 V to study their stability and performance. During cell cycling, the LNMO cell exhibited an initial capacity of 139 mAhg-1 at the C/10 rate with a capacity retention of 82% after 100 cycles. Remarkably, LNMO-Ce exhibits an initial capacity of 169 mAhg-1 with a 92% capacity retention at the same conditions. The microwave-assisted co-precipitation technique enables the development of microspheres with high interfacial stability and tap density, also the addition of protective ceria coating over the cathode enhances the cycling stability of the cathode at high voltage operation. Due to the novel material architecture and synthesis techniques, parasitic reactions at the electrolyte and active electrode material interface are avoided, Mn3+ dissolution is reduced due to the Jahn Teller effect, and conductive pathways are improved, significantly improving the electrochemical performance. When applied to other types of electrode materials, the suggested technique for material production is capable of significantly improving the materials' cyclic performance.
Material and Processing Considerations for Thick All Active Material Mildly Sintered Lithium-Ion Electrodes
Authors: Koenig Gary , Cai Chen , Nie Ziyang
Published: November 2022

Electrodes containing only electroactive material processed to relatively large thicknesses (often greater than 500 microns) can have high energy density at the cell level due to the high loading of electroactive material. The specific all electroactive lithium-ion material electrodes in this work undergo a mild thermal treatment and are referred to as sintered electrodes. While in general the great thickness results in long ion diffusion paths which limits rate capability of sintered electrode cells, the lack of inactive additives provides a relative advantage in effective ionic transport properties.

In this talk, recent improvements in sintered electrode batteries will be discussed. In particular, incorporation of new materials with increased gravimetric and more importantly volumetric energy density will be described. In some cases, the alternative materials have lower electronic conductivity than previously used electroactive materials for sintered electrodes, and processing strategies for alleviating electronic conductivity limitations will be discussed. Incorporation of modified materials and processing results in very high energy density small form factor battery cells.
Multiscale Simulation of Carbonate-Based Electrolytes for Li-Ion Battery
Authors: Allam Omar , Jang Seung Soon
Published: November 2022

Organic electrodes have been extensively studied for their application as cathode materials for Li-ion battery due to their relatively inexpensive synthesis, earth-abundant precursors, and their high-rate capabilities. In our previous studies, we developed hybrid machine learning-density functional theory protocols to predict and analyze the redox potentials for novel organic moieties. Although the prediction of the electrochemical activity is critical for the design of high energy density cathodes, one of the most detrimental challenges facing the practical application of organic electrode materials is their dissolution by liquid electrolytes. Therefore, it is necessary to investigate several avenues to curb this undesirable dissolution by the electrolyte. In this fundamental study, we investigate novel carbonate-based solid-polymer electrolytes (SPE) using MD simulations and compare their performance to their conventional liquid carbonate electrolyte counterparts. Specifically, we characterize how the nanophase morphology of the amorphous polycarbonate systems is affected by modulating the composition of the carbonate side chains, while comparing them with their liquid electrolyte counterparts such as dimethyl carbonate and ethylene carbonate. Moreover, our study will elucidate how the morphology and thermodynamic properties, such as glass transition temperature, are affected by using aliphatic vs aromatic carbonate side chains, mixing of the side chain types, as well as by adjusting the length of the spacer carbon chain between the carbonate groups and the main chain. Therefore, this investigation can provide valuable insight regarding the optimal polymeric composition and mixture to achieve a morphology that is desirable for enhanced ion transport, while also inhibiting the disintegration of the organic cathode by the electrolyte.
The Investigation of SOC Estimation Algorithm for High-Voltage Lithium Ion Battery of Construction Equipment
Authors: Jung Hong-Ryun , Kim Hee Su , Kim Jun Ho , Yun Jeong Woo
Published: November 2022

The estimation of the state of charge (SOC) is crucial to determine the remaining capacity of the lithium-ion battery, and thus plays an important role in many electric vehicles and construction equipment driven by the lithium-ion battery. In this study, the optimal algorithm was investigated for high-voltage lithium-ion batteries of construction equipment that can be operated under harsh environmental conditions. The SOC estimation algorithms are designed by combining the Extended Kalman Filter which is an adaptive control method for nonlinear systems. The discharge capacity profiles was evaluated under each C-rate and various temperature to estimate SOC accurately. Also, the internal parameters required for the electrical equivalent circuit model were obtained by measuring the OCV and internal resistance under various temperature and C-rate conditions for the battery cell and battery module, respectively. The proposed SOC estimation algorithm was achieved excellent performance with maximum error of less than 5%. Finally, the SOC estimation method was found to satisfy the precision requirements in various temperature conditions.
Transition Metal-Doped Ni-Rich Layered Cathode Materials for Sustainable Li-Ion Batteries
Authors: Sun H. Hohyun , Kim Un-Hyuck , Lee Soobean , Sun Yang-Kook
Published: November 2022

Doping is a well-known strategy to enhance the electrochemical energy storage performance of layered cathode materials. Many studies on various dopants have been reported; however, a general relationship between the dopants and their effect on the stability of the positive electrode upon prolonged cell cycling has yet to be established. Here, we explore the impact of the oxidation states of various dopants (i.e., Mg2+, Al3+, Ti4+, Ta5+, and Mo6+) on the electrochemical, morphological, and structural properties of a Ni-rich cathode material (i.e., Li[Ni0.91Co0.09]O2). Galvanostatic cycling measurements in pouch-type full Li-ion cells show that cathodes featuring dopants with high oxidation states significantly outperform their undoped counterparts and the dopants with low oxidation states. In particular, Li-ion pouch cells with Ta5+- and Mo6+-doped Li[Ni0.91Co0.09]O2 cathodes retain about 81.5% of their initial specific capacity after 3,000 cycles at 200 mAh g-1. Furthermore, physicochemical measurements and analyses suggest substantial differences in the grain geometries and crystal lattice structures of the various cathode materials, which contribute to their widely

Myung et al. ACS Energy Lett.
2017, 2, 196-223.

Kim et al. Energy Environ. Sci.
2018, 11, 1271-1279.

Kim et al. energy.
2020, 5, 860-869.

Kim et al. ACS Energy Lett.
2017, 2, 1848-1854.
Isomorphism in Ternary Mathematics
Authors: Pozinkevych Ruslan
Published: November 2022

Aims/ Objectives: Given research is an attempt to establish a connection between various groups of numbers The author aims to justify the statement: is true as an example of the so-called “Ternary Groups” Definition of “ Ternary” very much depends on vector properties and it’s components

Keywords: Three Component Vector ,Bayesian Decomposition ,Matrix of Rotation 1 Introduction

Let’s first write the definition of a three component vector :

It is a vector the components of which are orthonormal and is written as The indice x,y,z are commonly referred to as i,j,k units along x,y,z axis The question is whether such reference is correct As an example we use most commonly used dot and cross product often referred to as scalar and vector multiplication

The outcomes of these two products result in different classes of number presentations i.e., a scalar and a vector respectively Having said that we want to establish a link between numeric values and their vector representation

Figure 1
Enhanced Visible Light Transmittance and Phase Transition in ZnO/VO2 /AL2O3 Bilayer Thin Film for Energy Efficient Smart Windows.
Authors: Saharan Chirag
Published: November 2022

To ameliorate the limitation of low visible light transmittance of smart window, single phase Vanadium dioxide (VO2) and bilayer of Zinc oxide ZnO/VO2 on Al2O3 substrate were fabricated using the Radio frequency (RF) sputtering technique. These films were deposited at different temperature ranges starting from 28 degrees Celsius which goes up to 90 degrees Celsius. Structural Phase transition was witnessed from monoclinic to rutile phase after a critical temperature (Tc) of 68 degrees Celsius. Structural characterisation was done using the X-rays diffraction(XRD) analysis technique at grazing incidence mode by using monochromatic X – rays (λ = 0.06926 nm). Further, the morphology of the surface structures was studied by using field emission scanning electron microscopy (FESEM). The visible light transmittance change was studied using the Ultra Violet (UV) – Vis spectroscopy in transmittance mode at room temperature. This increased transmittance of the bilayer deposited can be a potential way out to have more efficient smart windows.
Advanced Concentration Gradient Cathode Material for Next-Generation Electric Vehicles
Authors: Park Nam-Yung , Kim Jae-Min , Sun Yang-Kook
Published: November 2022

With the prevalence of electric vehicles (EVs), the use of Li-ion batteries (LIBs) in EVs presents a new set of challenges such as cost, charging behavior, driving range per charge, risk of thermal runaway, and battery life. As the performance of LIBs is largely determined by the cathode material, the development of high-performance LIBs for EVs has focused on increasing the capacity of the cathode by using Ni-rich Li[NixCoyAl1−x−y]O2 (NCA) and Li[NixCoyMn1−x−y]O2 (NCM) cathodes.1

Ni-rich core encapsulated by a shell with concentration gradients (CSG) is the only field-proven strategy that is able to tap the potential capacity of Ni-rich cathodes while providing long cycle life.2 Despite the success of CSG cathodes, concentration gradients in the hydroxide precursor are intrinsically unstable and susceptible to flattening through interdiffusion during lithiation process.3 Furthermore, excessive coarsening during lithiation destroys the aligned microstructure, which undermines the mechanical stability of the cathode against microcrack formation.3 Therefore, CSG cathodes require a narrow processing temperature window; however, this increases their manufacturing cost.

Herein, it was demonstrated that the doping of a CSG cathode with an average composition of Li[Ni0.9Co0.5Mn0.5]O2 with 0.5 mol% Sb substantially improved its cycling stability while providing manufacturing flexibility. Sb doping allowed precise tailoring of the cathode microstructure through the retardation of cation migration and the inhibition of coarsening by pinning particle boundaries. The Sb-doped CSG cathode retained ~80% of its initial capacity for 2500 cycles, while the pristine CSG90 cathode showed similar capacitive deterioration over only 1500 cycles. The proposed Sb-doped CSG90 cathode for use in electric vehicles represents an ideal high-energy-density cathode with a composition engineered to maximize capacity; its modified microstructure ensures a long battery life and ease of manufacturing, enabling cost reduction.

Reference
s
:

[1] H.-J. Noh, S. Youn, C. S. Yoon, Y.-K. Sun, J. Power Sources, 2013, 233, 121.

[2] U.-H. Kim, H.-H. Ryu, J.-H. Kim, R. Mucke, P. Kaghazchi, C. S. Yoon, Y.-K. Sun, Adv. Energy Mater.
2019, 9, 1803902.

[3] G.-T. Park, H.-H Ryu, T.-C. Noh, G.-C. Kang, Y.-K. Sun, Mater. Today, 2022, 52, 9.
Emulating Excitatory and Inhibitory Functions in Artificial Synaptic Devices
Authors: Kim Dongshin , Lee Jang-Sik
Published: November 2022

Synaptic signals are controlled by neurotransmitters. The synaptic signals can be excited or inhibited depending on the types of neurotransmitters. The demonstration of the balancing between excitatory and inhibitory signals has important implications for the complex and efficient computing of the nervous system. Emulating the excitatory-inhibitory balancing behaviors of the nervous system is one way to establish neuromorphic computing. In this study, we demonstrate artificial synapses using PEDOT:PSS channel and neurotransmitter solutions to emulate the excitatory-inhibitory balancing behaviors. The devices show excitatory and inhibitory postsynaptic characteristics using the neurotransmitter solutions. Also, using the interaction between excitatory and inhibitory synaptic responses, the devices emulate the excitatory-inhibitory balancing behaviors of the nervous system. The devices exhibit multifunctional characteristics similar to the biological synapses, resulting in their potential for use in neuromorphic devices.
LIOVIXTM Printable Lithium Technology for Advanced Energy Storage Applications
Authors: Xia Jian , Fitch Brian , Cabaniss Joseph Emory , Black Rebecca , Watson Andrew , Reid Julian , Navulla Anantharamulu , Yakovleva Marina
Published: November 2022

Livent has developed LIOVIXTM printable lithium technology, that utilizes a stable lithium metal containing suspension that can be deposited on the most common substrates when a controlled amount of lithium metal is required. One of the most common uses of LIOVIX technology is pre-lithiation of anode electrodes. We have successfully demonstrated this technology in pre-lithiating of silicon-based anodes that contain from 5% to 100% silicon. LIOVIX can also be used to deposit thin lithium foils on current collectors, separators, and even solid or polymer electrolytes for lithium metal anode applications with controlled thickness and width. We have demonstrated printed lithium foils’ thickness in the range of 5µm to 50µm. LIOVIX technology is easily scalable using industry standard coating and printing equipment. The technology is flexible, cathode agnostic and adaptable to any energy storage device where an independent source of lithium is desired.
Estimating Surface Layer Thickness on Electrodes from Lithium-Ion Batteries By Surface Analysis
Authors: Zhou Liu (Amy) , Guillot Sarah Lucienne , Usrey Monica Lee , Peña-Hueso Adrián
Published: November 2022

As energy density and operational requirements increase, traditional battery electrolytes are pushed to the breaking point. Silatronix® organosilicon (OS) electrolyte materials are a key building block in next-generation Li-ion systems. Silatronix® has developed and synthesized an entirely new class of OS molecules with superior thermal, chemical, and electrochemical properties including lower anode and cathode impedance and reduce gas generation after high temperature cycling1.

The surface layers that form on the electrodes during battery aging are one of the main factors affecting the performance of lithium-ion batteries and can be key to understanding battery electrochemistry2. Thicker surface layers may lead to higher impedance while composition of the surface layer can also affect impedance. In this work, X-ray photoelectron spectroscopy (XPS) was used as the main tool to estimate the thickness of the surface layers on both cathode and anode (Figure 1). The anode surface layer thickness was estimated using depth profiling through the decomposition layer to reveal signal from the bulk anode. The cathode surface layer thickness was estimated using the PVDF signal from the bulk cathode and calculating the attenuation of the pristine signal due to the overlying decomposition species3.

Utilizing these methods, the surface layer thicknesses on the anode and cathode were estimated after formation, after HT cycling and after HT storage4. The trend of anode surface layer thickness with aging was explored, as well as the effects of different OS materials on surface layer thickness after different stages of aging, and the correlation between the cell impedance and surface layer thickness.

References:

Guillot, S.L.; Usrey, M. L.; Peña-Hueso, A.; Kerber, B.M.; Zhou, L.; Du, P.; Johnson, T. Reduced gassing in Lithium-ion batteries with organosilicon additives. Journal of The Electrochemical Society 2021, 168, 030533-030543.

Wang, A.; Kadam, S.; Li, H.; Shi, S.; Qi, Yue. Review on modeling of the anode solid electrolyte interphase (SEI) for lithium-ion batteries, npj Computational Materials 2018, 4, 15.

Cumpson, P.J. The Thickogram: a method for easy film thickness measurement in XPS. Surf. Interface Anal. 2000, 29, 403-406.

Niehoff, P.; Passerini, S.; Winter, M. Interface investigations of a commercial Lithium-ion battery graphite anode material by sputter Depth Profile X-ray Photoelectron Spectroscopy. Langmuir 2013, 29, (19), 5806–5816.

Figure 1
Malonatophosphate As a Dual Functional Additive That Outperforms Unsymmetrical Fluorinated Malonatoborate for LiNi0.8Co0.1Mn0.1O2/Graphite Lithium-Ion Batteries
Authors: Park Jong Won , Park Doh Hee , Lee Hochun
Published: November 2022

The practical use of Ni-rich NCM cathode materials has been plagued by their poor thermal stability, especially at high-temperature (60 °C). In this study, we introduce lithium tetrafluoro(fluoromalonato)phosphate (LFMP) as a dual-functional electrolyte additive to improve the thermally stability of both LiNi0.8Co0.1Mn0.1O2 (NCM811) cathode and graphite anode materials. LFMP additive enables excellent cyclability, storage performance, and mitigated gas evolution of NCM811/graphite cells at 60 °C compared with its boron analogue, lithium difluoro(fluoromalonato)borate (LFMB). The underlying origin of the benefits of LFMP are elucidated to be two folds: (i) on the NCM811 cathode, LFMP derives a cathode electrolyte interphase (CEI) that suppresses electrolyte decomposition and gas evolution more effectively than LFMB-derived CEI, (ii) on the graphite anode, LFMP derives a LiF-rich solid electrolyte interphase (SEI) that is resistant to the attack by HF and PF5, compared to an organic-rich, LFMB-derived SEI. Our first-principles calculations corroborate that LFMP is superior to LFMB owing to the strong binding with a superoxide radical, the weak binding with PF5, and the favorable LiF formation upon electron reductions. Considering its formidable advantages, LFMP is an outstanding electrolyte additive for thermally stable NCM811/graphite batteries.
Al3+ Doped Li(Ni-Ni0.9Co0.1)O2 Core-Shell Cathodes for Rapid Charging and Dramatic Cycle Performance
Authors: Park Eui Jeong , Kim Hae In , Jang Hyun Ju , Tran Thi Bich Thuy , Kim Il Song , Hong Tae Whan , Kang Jeong-Won , Lee Yun Kyung , Kim Hag Wone , Lim Jeong Hyurk , Son Jong-Tae
Published: November 2022

Nickel-rich layered Li(Ni-Ni0.9Co0.1)O2 is a promising cathode material due to its high specific capacity. However, commercial application of this material is impeded by its rapid capacity degradation associated with structural instability. In this work, 0.01mol Al3+ Doped Li(Ni-Ni0.9Co0.1)O2 cathode material is prepared by heat treatment of a mixture of stoichiometric amounts of nano-sized Al(OH)3 powders, co-precipitated (Ni-Ni0.9Co0.1)(OH)2 precursors, and LiOH·H2O. The results show that Al3+ doping significantly improves the cycling properties of Li(Ni-Ni0.9Co0.1)O2 cathode material. Under a voltage range of 3–4.5 V, 0.02 mol% Al3+ doped Li(Ni-Ni0.9Co0.1)O2 cathode material shows an initial discharge capacity of 210 mAh/g at 0.1C, with a capacity retention of 97% for subsequent 100 cycles at 1C at room temperature. In contrast, bare Li(Ni-Ni0.9Co0.1)O2 shows a capacity retention of only ~62.8% under the same conditions, with an initial specific discharge capacity of 220 mAh/g. The improvement in cycling performance is attributed to stabilization of the layered structure by Al3+ , mitigated migration of Ni2+ to the Li layer, improved lithium diffusion kinetics and reduced lattice expansion/shrinkage during cycling. Stabilization of the layered structure by Al3+ doping is further reflected by the observation of fewer cracks in cathode electrodes after prolonged cycling.
NMC111 Cathode Thin Films for All Solid State Li Ion Battery
Authors: Uzakbaiuly Berik , Mukanova Aliya , Bakenov Zhumabay
Published: November 2022

This work investigates the electrochemical properties of NMC111 as thin film cathode materials for thin film Li ion batteries. The films were deposited on Si substrate coated with Pt using a radio frequency magnetron sputtering system. The samples were post annealed after deposition and the it’s effect is discussed. Crystalline structures were obtained for samples annealed at 700 oC and O2 atmosphere. The electrochemical properties of all solid state thin film batteries with the crystalline cathode, Lipon electrolyte and Li anode showed good capacity retention. This battery proved to be an effective solution for thin film and microbatteries.

Acknowledgement

This research was funded under the research grant #51763/ПЦФ-МЦРОАП РК-19 “New materials and devices for defense and aerospace applications” from MDDIAI Republic of Kazakhstan
Improving Performance of Regenerated Cathode Materials from Aged Lithium-Ion Batteries By Forming Nano-Coatings
Authors: Yan Chao , Koel Bruce , Yang Xiaofang , Xiang Jerry
Published: November 2022

Lithium-ion batteries (LIBs) have emerged as the battery of choice for rapidly growing markets in electric vehicles (EVs) and grid electricity storage. This spurs a great demand for lithium, graphite, cobalt, and nickel that could outstrip the supply of virgin materials. Thus, there is an enormous interest in the development of new sustainable technologies for recycling and recovery of valuable materials from secondary resources, especially from used lithium-ion batteries. Compared to conventional high-temperature pyrometallurgical or hydrometallurgical methods, direct recycling of LIBs is a more desirable approach because it can directly regenerate the cathode materials by relithiation without destroying the LIB compounds. Additionally, direct recycling is a comparatively low-cost and less resource-intensive method of recovering LIB materials.

However, completely regenerating the full capacity and long-term performance of the original materials is still particularly challenging. For instance, the cathode materials are often coated with a nanometer-thick protecting layer, which is engineered to reduce the degrading effect on the cathode from direct contact with the electrolyte. The long-term charge-discharge cycling causes damage to this coating layer, and thus it needs to be repaired in order to recover the material performance. To address this challenge, we have developed a novel process that can regenerate and upgrade cathode materials from aged lithium-ion batteries, as well as create a new coating layer to improve the performance of the cathode materials. In this presentation, we will provide a case study to show the performance improvement of recycled lithium cobalt oxide (LCO) materials by forming an alumina coating layer on the surface. By controlling the thickness and sintering temperature, this surface alumina coating can be an effective way to improve the stability and cyclability of recycled LCO cathode materials. Material characterization by XPS, SEM, STEM, and XRD helps to reveal the structure and composition of the surface alumina coating layer, and provides insights into the healing and protective roles of this layer for recycled LCO particles.
Exposing Heterogeneous Degradation in Prismatic Lithium-Ion Cells
Authors: Smith Alexander James , Mikheenkova Anastasiia , Fang Yuan , Ahmed Istaq , Ekström Henrik , Svens Pontus , Furo Istvan , Hahlin Maria , Lacey Matthew , Lindbergh Göran , Wreland Lindström Rakel
Published: November 2022

The energy density and lifetime of lithium-ion cells for automotive applications have both substantially improved in recent years. This enables electric vehicles in both the consumer and commercial sectors that have greater range, better reliability, and longer service lives [1]. These factors all contribute to the widespread adoption of electric vehicles. However, inhomogeneities exist within cells that contribute to uneven internal degradation and, when severe, can trigger rapid failure. These inhomogeneities can be related to manufacturing tolerances or distributions of component parameters [2], as well as gradients in internal or external conditions. As such, the reality of heterogeneous aging is a complex, multivariate problem to solve.

In this latest work, we cycle automotive-grade prismatic cells for several thousand cycles (until 10-30 % capacity fade) and harvest components for post mortem aging characterization and experimental parameter identification. The constituent electrodes are a Ni-rich layered oxide (approximately LiNi0.76Mn0.15Co0.09O2) and graphite. In addition to microscopy and electrochemical testing on harvested electrodes, we quantify local lithium plating on graphite with our recently developed method utilizing ex-situ, 7Li nuclear magnetic resonance spectroscopy [3]. We believe this to be the first report of spatially-resolved lithium plating quantification in commercial lithium-ion cells. Clear patterns emerge (see Figure 1), reflecting the geometry of the cell and showing reproducible heterogeneity that cannot be attributed solely to defects in manufacture. Several tests even confirm local lithium plating and unusually rapid degradation at comparatively mild cycle conditions (slow charge/discharge, low state-of-charge, and room temperature).

The wound jellyroll design in contemporary prismatic cells enables very high packing efficiency and energy density, but includes inherently weak points from where lithium plating and internal stresses [4] can propagate. In some cases, cells achieve satisfactory lifetimes without accelerated aging. In others, heterogeneities cause extreme local degradation that triggers end-of-life even though other regions may remain relatively intact. We explore the causes of these patterns and question how such damage can occur, even under cycling conditions usually considered safe.

References

[1] P. Svens et al., IEEE Trans. Transp. Electrif., (2022), doi:10.1109/TTE.2022.3158838.

[2] D. Beck et al., Energies, 14 (2022), 3276, doi:10.3390/en14113276.

[3] Y. Fang et al., manuscript submitted, (2022).

[4] P. Gupta and P. Gudmundson, J. Power Sources, 511 (2021), 230465, doi:10.1016/j.jpowsour.2021.230465.

Figure 1
Quantifying the Thermo-Electrochemical Sensitivity of Li-Ion Batteries to Modulating Interelectrode Thermal Gradients
Authors: Ishtiaque MD Mahdi UL , Ramamurthy Jayanth R. , Pint Cary L. , Kingston Todd A.
Published: November 2022

Li-ion secondary batteries are used in many applications and technologies as energy storage devices because of their relatively high Coulombic efficiency and energy and/or power density. However, Li-ion batteries (LIBs) are prone to safety concerns (e.g., thermal runaway), which limit their application [1]. Thermal conditions are one of the major parameters that influence the safety and performance of LIBs due to temperature-dependent electrochemistry. Low temperatures [2] and high temperatures [3] have distinct effects on LIB electrochemistry and are well-reported in the literature. Although non-uniform thermal conditions are more practical during use, the effect of various non-uniform thermal conditions is not fully understood. A non-uniform temperature distribution can easily develop inside Li-ion cells by surface cooling, and the resulting thermal gradient can have adverse effects. Moreover, the direction of the thermal gradient can dictate local transport mechanisms and can cause different degradation modes [4]. Thus, further assessment of the impact of thermal gradients is needed to fully understand the fundamental electrochemical mechanisms, performance, and safety implications. In this work, we quantify the thermo-electrochemical sensitivity of LIBs to modulating interelectrode thermal gradients in synchronization with electrochemical cycling using a custom test facility. Instrumented single-layer pouch cells are fabricated using NMC cathodes and graphite anodes. The internal temperature of each electrode is obtained in real-time using a thin thermistor. Electrochemical impedance spectroscopy is performed before and after galvanostatic cycling at C/5, and the magnitude and the direction of the thermal gradient in synchronization with cell cycling is varied.

Acknowledgments

The authors thank Dr. Michele Anderson (Office of Naval Research, grant N00014-21-1-2307) for financial support of this work. The authors also acknowledge Dr. Corey Love and Dr. Rachel Carter (U.S. Naval Research Laboratory) for technical discussion of this work.

References

[1] X. Wu, K. Song, X. Zhang, N. Hu, L. Li, W. Li, L. Zhang, H. Zhang, Safety Issues in Lithium Ion Batteries: Materials and Cell Design, Frontiers in Energy Research, 7 (2019).

[2] H.P. Lin, D. Chua, M. Salomon, H.C. Shiao, M. Hendrickson, E. Plichta, S. Slane, Low-temperature behavior of Li-ion cells, Electrochemical and Solid-State Letters, 4(6) (2001) A71-A73.

[3] P. Ramadass, B. Haran, R. White, B.N. Popov, Capacity fade of Sony 18650 cells cycled at elevated temperatures, Journal of Power Sources, 112(2) (2002) 614-620.

[4] R. Carter, T.A. Kingston, R.W. Atkinson, M. Parmananda, M. Dubarry, C. Fear, P.P. Mukherjee, C.T. Love, Directionality of thermal gradients in lithium-ion batteries dictates diverging degradation modes, Cell Reports Physical Science, 2(3) (2021) 100351.
Thermal Runaway Mitigation for Batteries in Shipping Configurations
Authors: Joshi Tapesh , Jeevarajan Judith
Published: November 2022

The widespread and increasing adoption of lithium-ion batteries for multiple applications has accelerated the demand for batteries. Updated transportation safety guidelines must be followed in order to avoid hazards during the shipment of batteries from manufacturing sites to end-consumers. Despite existing guidelines in place, there have been instances of battery-related safety hazards during transportation. Different off-nominal conditions arising due to mechanical, electrical, or environmental conditions can lead lithium-ion cells into failure and cause thermal runaway in worst-case scenarios. Outcomes including smoke, high temperatures, fire, and explosion are possible following a thermal runaway event. Hazards are magnified when thermal runaway in a single cell is propagated to other cells within a package or battery causing a chain of highly exothermic reactions.

In this study, effectiveness of several barrier materials was tested to mitigate the propagation of thermal runaway occurring in a single cell within the package. 25-cells configurations of lithium-ion cells were placed within shipping boxes and a single cell at the center of the configuration was triggered using an external heating method to go into thermal runaway. Among different test variations, regular cardboard and UN-rated shipping boxes were tested. Test articles were arranged in 25 single cell configurations (not connected) representing shipment of loose cells and 25P electrically connected configurations representing shipment of batteries. Barrier materials with 2 mm to 4mm intercell separation and different physical properties were tested. The materials tested were either in sheet form or a mold-pattern. State-of-charge (SOC) of all the cells in the container were either at 33% SOC or 100% SOC to represent current shipping SOC regulations and to study the worst-case hazard conditions.

Thermally insulating, conducting, and phase changing materials along with their effectiveness in mitigating the propagation of thermal runaway will be discussed. Additional thermal management requirements in batteries due to the conduction through tabs will also be highlighted through the results. Requirements for flame and fire retardation for preventing rapid propagation of thermal runaway will be presented. Efficacy of materials from different manufacturers at preventing the propagation of thermal runaway will be summarized.
Ga+ Focused Ion Beam Damage in n-type Ga2O3 and Its Recovery after Annealing Treatment
Authors: Xia Xinyi , Al-Mamun Nahid , Daudi Warywoba , Ren Fan , Haque Aman , Pearton Stephen J
Published: November 2022

In this study, the focused ion beam (FIB) Ga+ irradiation damage on β-Ga2O3 Schottky diode structure under different ion energies were tested, and the effective recovery of diode characteristics after rapid thermal annealing (RTA) post-annealing were also studied.

β-Ga2O3 based Schottky diodes have attracted increasing attention because of the prospects for use in next-generation high-power electronics. Focused ion beam (FIB) machining is one of the newest processing techniques, which is mainly used in semiconductor and chip manufacture and transmission electron microscopy (TEM) sample preparation. During FIB sample preparation, the energetic Ga ions are incident onto the sample to induce physical sputtering of the material, which in turn, modifies its chemical composition, crystallinity and electrical properties. It has been found in many studies that 20-30 nm amorphous layer can form on silicon after irradiation with 30 keV Ga ions. From our previous study, the FIB ion beam induced damages could cause significant degradation on diode on-resistance and turn-on voltage. Milling at lower energy has been used to reduce the electrical damage. However low energy milling is more time consuming and less precise. Short-time, high-temperature post-annealing treatments, such as RTA has been proved could remove the crystal damage. Thus, there is a great need to determine the maximal ion beam energy and post-annealing temperature for FIB without degrading diode characteristics.

In this work, energies ranging from 2 keV to 30 keV were employed to mill off a part of Ga2O3 epi-layer and Schottky diodes were fabricated on milled surface. Forward IV characteristic shows less degradations with lower ion beam energies. For the diodes exposed to 2, 5, and 10 keV Ga+ ion beams exhibited significant recovery of diode on resistance and turn-on voltage after 300°C RTA annealing. For the diodes exposed to 30 keV Ga+ ion beams recovered significantly after 400 °C annealing. In conclusion, decreasing the FIB energy shows effective alleviations on the FIB damage, and post annealing treatment effectively recovered the damage from Ga+ implantation.

This is the first time the thermal annealing treatment was performed for Ga2O3 Schottky diode recovering from FIB cutting, it is an effective and simple way to mitigate the degradation, especially for higher ion beam energies. This work could broaden the FIB’s usability and release tremendous potential as a specimen preparation and imaging tool in materials science applications.

Figure 1
Device-Level Impact of Highly Anisotropic Thermal Conductivity of AlN/GaN Digital Alloys
Authors: Aller Henry Tyler , Chaney Alexander , Pfeifer Thomas , Averett Kent , Asel Thaddeus , Hopkins Patrick E , Mou Shin , Graham Samuel
Published: November 2022

AlN/GaN digital alloys (i.e., short period superlattices) have the advantage of being an ultra-wide bandgap due to the quantum confinement effect, preservation of high mobility (no strong alloy scattering), and higher thermal conductivity than AlGaN random alloys.

Herein, we investigate the influence of AlN/GaN thickness combinations on digital alloy (DA) thermal conductivity. Using time-domain thermoreflectance and steady-state thermoreflectance, we measure the anisotropic thermal conductivity of AlN/GaN DA’s, with thickness combinations: (2 nm/1 nm), (4 nm/1 nm), (6 nm/1 nm), (11 nm/1 nm). DA's with thick AlN layers exhibit highly anisotropic thermal conductivity (i.e., 4x difference between cross-plane and in-plane).

Using finite-element modeling, we thermally simulate AlGaN and AlN/GaN DA devices. Improved lateral heat spreading in DA devices results in lower hot-spot temperatures compared to AlGaN devices. As the first thermal measurements of AlN/GaN DA’s, this study provides guidance for future device design.
(Invited) Spin and Optical Properties of the Silicon Vacancy in 4H-SiC for Quantum Science and Technology
Authors: Carter Samuel G , Lekavicius Ignas , Banks Hunter B , Soykal Oney O , Pavunny Shojan P , Pennachio Dan , Hajzus Jenifer R , DeJarld Matt T , Yeats Andrew L , Brereton Peter G , Glaser Evan R , Purdy Andrew P , Bielejec Ed , Myers-Ward Rachael L , Gaskill David Kurt , Reinecke Thomas L
Published: November 2022

Silicon vacancies in SiC are of significant interest for quantum information and sensing due to their unusual combination of long spin coherence time, optical addressability, and room-temperature operation in an industrially-relevant semiconductor. We characterize the spin and optical properties of the V2 silicon vacancy in 4H-SiC for both single defects and ensembles. We also show that they can be deterministically placed with sub-micron precision using focused Li ion implantation. Low-temperature photoluminescence excitation spectroscopy of the spin-dependent optical transitions of single silicon vacancies reveals two sharp lines with linewidths near the radiative lifetime limit. These lines correspond to the ms=±1/2 and ms=±3/2 states of an S=3/2 spin system that can be optically initialized, coherently manipulated with RF pulses, and read out via spin-dependent photoluminescence. We measure the different properties of spins in the two bases, and compare them to theoretical models. To suppress the limiting effects of the nuclear spin bath, we grow isotopically purified SiC with a very low abundance of 29Si and 13C. Our room temperature spin coherence measurements show orders-of-magnitude improvement of the coherence times in these materials. In particular, the inhomogeneous dephasing time T2
* in the ms=±1/2 basis shows a ~100x improvement, reaching 20 μs. We consider the prospects of this system for quantum sensing and as an efficient spin-photon interface for use in quantum networks.

This work was supported by the U.S. Office of Naval Research, the OSD Quantum Sciences and Engineering Program, the Defense Threat Reduction Agency, and the Center for Integrated Nanotechnologies, an Office of Science User Facility operated for the U.S. Department of Energy (DOE) Office of Science. Sandia National Laboratories is a multi-mission laboratory managed and operated by National Technology and Engineering Solutions of Sandia, LLC., a wholly owned subsidiary of Honeywell International, Inc., for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-NA-0003525.