bluuebunny/crossref_metadata_2025 huggingface dataset:
Quantifying the Inactivation of Battery Electrode Material Particles
Authors: Wiemers-Meyer Simon , Vahnstiege Marc , Kroeger Till-Niklas , Harte Patrick , Beuse Thomas , Wölke Mathis Jan , Klein Sven , Börner Markus , Winter Martin , Nowak Sascha
Published: February 2024

Lithium ion batteries, like any other battery technology, tend to lose capacity with continued charging and discharging. One of the effects contributing to the decline in capacity is the inactivation of positive electrode material particles. The electrodes typically consist of polydisperse active material particles, a conductive agent and a binder. By charging and discharging of the battery the active material particles are lithiated and delithiated. If a particle becomes inactive, e.g. by losing the electronical contact or by the formation of ion blocking surface films, it stops following the lithiation and delithiation of the rest of the electrode. Analyses of the degree of lithiation (DOL) of single particles therefore provide valuable information on the capacity loss attributed to inactive particles.[1-3]

Since TOF-SIMS and synchrotron-based techniques which are usually used to determine the lithium content of single electrode particles only analyze small areas of the electrodes and are not well suited for measuring large numbers of samples, a method has been developed applying common ICP-OES instrumentation. For the determination of the DOL of single particles, the most important advantage of many ICP-OES instruments is the simultaneous detection of several elements. In case of common positive electrode materials such as Li(NixMnyCoz)O2 (x+y+z=1) (NMC) the ratio of e.g. Li to Mn signal intensities can be used to determine the DOL. As an aqueous sample introduction cannot be used because these materials would undergo Li+/H+ exchange reactions, a sample introduction using argon gas that furthermore enables a classification of particle sizes was developed.

This presentation will focus on the method development and application of single particle ICP-OES for battery materials. It will be shown how this method helps to elucidate the mechanisms of capacity fading, and the advantages and disadvantages of ICP-OES will be compared with those of alternative methods for this application. Different parameters affecting the inactivation of poly- and single-crystallin NMC particles will be discussed.

[1] T. N. Kroger, S. Wiemers-Meyer, P. Harte, M. Winter, S. Nowak, Analytical Chemistry
2021, 93, 7532-7539.

[2] T.-N. Kröger, P. Harte, S. Klein, T. Beuse, M. Börner, M. Winter, S. Nowak, S. Wiemers-Meyer, J. Power

Sources
2022, 527, 231204.

[3] Kröger, T.-N.; Wölke, M. J.; Harte, P.; Beuse, T.; Winter, M.; Nowak, S.; Wiemers-Meyer, S. Chemsuschem
2022, 15, e202201169.

Figure 1
Speciation of Transition Metal Dissolution in Electrolyte from Common Cathode Materials
Authors: Rynearson Leah , Tiano Sophia , Jayawardana Chamithri , Antolini Cali , Yeddala Munaiah , Hayes Dugan , Lucht Brett L.
Published: February 2024

Significant capacity loss has been observed across extended cycling of lithium-ion batteries to high temperatures and high voltages. This occurs due to transition metal dissolution from the high voltage spinel or layered oxide cathode material, ion migration through the electrolyte, and deposition on the solid-electrolyte interphase (SEI) on the anode. While much research has been done to track the oxidation state of the transition metal in the cathode material or deposited on the anode, there have been mixed reports on the chemical state of the transition metal ions dissolved in the electrolyte depending on the type of cathode used. X-ray absorption near edge spectroscopy (XANES) was performed on electrolytes extracted from full cells built with four different cathode materials that were cycled at either high or standard voltages to determine the chemical state of Mn and Ni in solution. Inductively coupled plasma-mass spectrometry (ICP-MS) was performed on the anodes from these cells to determine the concentration of deposited metal ions.
(Electrodeposition Division Research Award) New Frontiers of Electrodeposition for Metallic Finishes
Authors: Innocenti Massimo , Giurlani Walter , De Luca Antonio , Bonechi Marco , Comparini Andrea , del Pace Ivan , Verrucchi Margherita , Caneschi Andrea
Published: February 2024

The interest in scientific research within the metal finishing sector is growing. The demand for durable metals and adaptable manufacturing processes is increasing across a wide range of applications, from aerospace and automotive to machinery and jewelry. In that respect, alloy plating offers better answers in terms of economic growth and environmental sustainability due to fine-tuning composition, morphology, and crystallinity [1]. Here, current trends in alloy electrodeposition research are reviewed highlighting open challenges and process innovations from an industrial perspective. Combining basic electrochemical techniques with spectroscopic, microscopic, and structural techniques is crucial for characterizing the structure-activity relationship for many different technological devices. Particular attention is devoted to advances in industrial quality control and viable solutions for the reduction of precious metal content in electroplated accessories as well as the replacement of cyanide and nickel baths with non-toxic compounds. Project funded under the National Recovery and Resilience Plan (NRRP), Mission 4 Component 2 Investment 1.3 - Call for tender No. 341 of 15 March 2023 of Italian Ministry of University and Research (MUR) funded by the European Union - NextGenerationEU - Project code PE_00000004, CUP B83C22004890007, Project title "3A-ITALY - Made-in-Italy circolare e sostenibile".

References

[1] W. Giurlani, M. Innocenti et all. , Electroplating for Decorative Applications: Recent Trends in Research and Development, Review, Coatings 2018, 8(8), 260.
(Invited) A Novel Dems Approach for Studying Gas Evolution in Pouch Cells
Authors: He Meinan , Cai Mei
Published: February 2024

In this study, we designed a novel differential electrochemical mass spectrometry (DEMS) system to in-situ quantify the gas generation in batteries. While a lot of battery gas analyses were carried out by DEMS previously, most of those studies were based on small coin cells or EL cells. The fluid electrolyte and limited amount of active material may make it challenging to quantify the gas generation. The DEMS we designed here can continually sample gas from a small 2.5Ah pouch cell, and it has a similar electrolyte to capacity ratio, 1.8g/Ah, with our production cell. To the best of our knowledge, this is the first DEMS design based on a pouch cell.

Moreover, by using flowrate-controlled Ar carrier gas and a reasonable residence time setup, our DEMS design not only can identify volatile electrolyte degradation products throughout battery cycling but also quantify the gaseous species production rates as a function of the state of charge. We found that cell chemistry and operation protocol greatly impact gas product species, the production profile of different gases during cycling, and the total gas quantity. For example, the gas evolution of oxidation products, such as CO2 and CO, is exacerbated by the elevated upper cutoff voltage, while reduction products are only minimally affected. Furthermore, changing the electrolyte SEI former, from EC to FEC, or adding different electrolyte additives can affect the gas product species generation dramatically as well.

Therefore, we successfully demonstrated DEMS as a powerful tool to probe the gas evolution behavior in different applications-based batteries, provided valuable data for battery reactivity simulation, and most importantly, provided guidance for electrolyte optimization.
Single-Crystal Li1+x[Ni0.6Mn0.4]1-xO2 Made By All-Dry Synthesis
Authors: Garayt Matthew D. L. , Zhang Ning , Yu Svena , James Abraham Jeffin , Murphy Aidan , Omessi Roee , Ye Ziwei , Azam Saad , Johnson Michel B. , Yang Chongyin , Dahn Jeff R.
Published: February 2024

Single-crystal LiMO2 (M = 3d transition metal such as Ni, Mn, Al, and Co) has received much attention as a positive electrode material over the last few years due to its superior cycling stability over conventional polycrystalline materials1. Moreover, Co has fallen out-of-favour as a transition metal of choice due to its relatively high cost2 and the human rights abuses associated with its mining3. As well, the synthesis of conventional LiMO2 materials requires complex co-precipitation equipment that not only increases the cost of manufacture, but also produces waste such as Na2SO4. Furthermore, coating W on the particles’ surface in a separate step after co-precipitation improves the electrochemical performance of these materials4. Therefore, Co-free, W coated, single-crystal LiMO2 materials, made in a simple synthesis process like LiNi0.6Mn0.4O2 (NM64) are of most interest.

In this presentation, a simple, solvent- and waste-free synthesis method is shown to create NM64 materials with and without a W coating. This all-dry synthesis uses a mixture of metallic Ni, MnO2, LiOH·H2O, and an optional W precursor, along with two to three heating steps, and an agglomeration separation step to produce single-crystal NM64. The resulting material is R-3m phase pure with ≤4% Ni in the Li layer and contains only trace residual lithium. Additionally, the NM64’s grain size is between 2 to 5 µm, as shown in Fig. 1a), which can be tuned by the addition of W during the initial synthesis rather than with a separate coating step. While W inhibits grain growth during synthesis4, the Ni, Mn, and Li interdiffusion is largely unaffected according to the unit cell parameters and the Ni in the Li layer obtained from Rietveld refinement of their XRD patterns. Fig. 1b) illustrates that while NM64 materials without W retain 91% of their original capacity after 100 cycles at C/5, matching the vendor material, when W is added they outperform it with 93% retained capacity. It is believed that this incredibly simple process could be adopted relatively easily into current commercial positive electrode manufacturing facilities to reduce the complexity, cost, and time of manufacture.

Figure 1. (a) shows SEM micrographs of the all-dry synthesized NM64 material without and with W. (b) shows half coin cell cycling of NM64 materials with and without W as compared to a vendor material.

References

J. Li et al., J Electrochem Soc, 164, A1534–A1544 (2017).

Mining.com https://www.mining.com/markets/.

J. P. Otamonga and J. W. Poté, J Geochem Explor, 208, 106394 (2020).

D. Rathore et al., ACS Energy Lett, 7, 2189–2195 (2022).

Figure 1
Synthesis, Structural and Electrochemical Investigation of Disordered Rock Salt Compounds Based on Ni and Ti
Authors: Reitano Agnese , Kunz Sylvia , Bianchini Matteo
Published: February 2024

Li-ion batteries achieved in the last 3 decades extremely high energy densities, making them the energy storage devices of choice for the electrification of our society. Despite this improvement, their energy density is still low as compared to gasoline, motivating further research towards materials with better performances. State of the art positive electrodes are nowadays layered materials with a ratio Li:M of 1:1, with M being one or multiple transition metals. Disordered rock salt (DRX) materials without a layered structure were thought to be electrochemically inactive. With the development of the percolation theory, 1(Urban, Lee, and Ceder) it was demonstrated that lithium-rich materials (Li:M>1) with a cation disordered rock-salt structure (DRX) can achieve high reversible specific capacities. The general formula of these lithium-rich compounds can be written Li1+y(MM′)1−yO2 where the Li content ranges usually from 1.05 to 1.33, essential to promote Li percolation pathways. With M is indicated a redox active specie (Mn, Ni, Fe, Cr, V) and M’ is typically a d0 element, which is redox inactive during charge and discharge and therefore stabilizes the disordered structure and acting as charge compensator.2 (Chen, Ahn, and Chen)

In this work a class of Li-rich compounds with the chemical composition Li2yNiyTi2-3yO2 has been investigated (y = 0.50, 0.55, 0.60, 0.67). These samples were prepared via solid-state reaction at three different temperatures (700 °C, 800 °C, 900 °C). X-ray diffraction has been used to determine the crystal structure of the samples, revealing a predominant rock salt-type phase. However, by decreasing the synthesis temperature and increasing the Li content, phase separation occurs into a rock salt-type and a Li2TiO3 phase. The synthesis has been also verified by DFT and by in situ X-ray diffraction. Neutron diffraction experiment have been carried out to fully understand the cationic distribution in the samples. Finally, the electrochemical performances of the samples have been investigated in Li half cells, revealing a strong voltage hysteresis between charge and discharge.3 (Li et al.)

Bibliography

Urban, Alexander, Jinhyuk Lee, and Gerbrand Ceder. “The Configurational Space of Rocksalt-Type Oxides for High-Capacity Lithium Battery Electrodes.” Advanced Energy Materials 4, no. 13 (September 2014): 1400478. https://doi.org/10.1002/aenm.201400478.

Chen, Dongchang, Juhyeon Ahn, and Guoying Chen. “An Overview of Cation-Disordered Lithium-Excess Rocksalt Cathodes.” ACS Energy Letters, March 17, 2021, 1358–76. https://doi.org/10.1021/acsenergylett.1c00203.

Li, Biao, Khagesh Kumar, Indrani Roy, Anatolii V. Morozov, Olga V. Emelyanova, Leiting Zhang, Tuncay Koç, et al. “Capturing Dynamic Ligand-to-Metal Charge Transfer with a Long-Lived Cationic Intermediate for Anionic Redox.” Nature Materials 21, no. 10 (October 2022): 1165–74. https://doi.org/10.1038/s41563-022-01278-2
(Olin Palladium Award Address) Our Path to Long Lifetime Li-ion and Na-ion Cells
Authors: Dahn Jeff R.
Published: February 2024

In 2008, I was sitting with graduate student Aaron Smith one evening and we wondered how a University could make a contribution to the development of Li-ion batteries with decades of lifetime. This conversation led to the development of Ultra High Precision Coulometry, Battery Isothermal Microcalorimetry (with 3M collaborators), in-situ volume measurements of gas generation and electrode stack growth, among other tools. Results from these tools point the way to chemistries that can deliver long lifetime and I will give examples which show the value of these tools. However, in the end, there is really no way to be absolutely certain about long lifetime other than by testing for years and years, even at elevated temperature. I will show results that suggest lifetimes of over 50 years can be obtained for Li-ion cells are simple to make.
(Invited) Controlling Nucleation and Growth of Lithium Metal for High Performance Batteries
Authors: Liu Ping
Published: February 2024

The cycling behavior of the lithium metal anode determines the life time of lithium metal batteries when paired with common oxide or polymer-based sulfur (e.g., sulfurized polyacrylonitrile, SPAN) cathodes. Significant progress has been made on electrolyte engineering to improve the morphology of lithium metal. Those electrolytes with high concentration or weakly solvating solvents have shown most promise due to the promotion of anion-cation ion pairing and the reduction in desolvation energy.

On the other hand, gaining control of the lithium nucleation and growth remains challenging. We have shown recently that the substrate plays an important role in dictating lithium nucleation. An in-situ formed Fe/LiF substrate has been shown to lead to uniform lithium nucleation and fast lithium surface transport, resulting in the formation of hexagonal lithium single crystal seeds. These faceted seeds promote subsequent dense lithium growth even after repeated cycles. Importantly, the growth of porosity and the pulverization are effectively mitigated.

In this talk, we systematically analyze the factors that contribute to the single crystal growth and strive to quantify the different kinetic processes (surface transport, electrolyte transport, bulk diffusion, charge transfer) that collectively determine the seed growth behavior. On the other hand, we will describe our implementation of the nucleation control mechanism on a lithium metal foil so that these electrodes can be paired with non-lithium containing cathodes. We have found that adding nucleation agents to the lithium metal mitigates the formation of random pits during lithium stripping and subsequently promote the formation of dense lithium layer on top. As a result, a Li/SPAN battery with an areal capacity of > 7 mAh cm-2 has demonstrated stable cycling for over 200 cycles. Adding nucleation control measures to lithium metal is thus a promising approach to improve the cycle life of lithium metal batteries.
Thin, Conformal Carbon-Coating of Silicon-Phosphorus Nanoparticle Agglomerates for Lithium-Ion Battery Anodes
Authors: Lai Samson Yuxiu , Nordby Tommy Vikan , Kuhn Raphael , Koposov Alexey , Andersen Hanne Flaten
Published: February 2024

Efforts to further enhance the capabilities of silicon as a lithium-ion battery anode are continuing into the realm of chemical composition. Adding varying amounts of other elements can significantly alter the material properties or side reactions, which influence electrochemical performance. Additionally, tuning the chemical composition combined with surface modifications can better enable application of silicon anodes in other devices such as hybrid supercapacitors.

Prior work, among others, has shown different performance enhancement regimes depending on how much phosphorus is added to silicon-containing anodes [1, 2]. In particular, the amount of phosphorus from ppm levels to majority atomic fraction can result in enhancement in the conductivity, diffusivity, or forming altogether a wholly new protective matrix [3]. However, while the rate capability has been enhanced only primarily for delithiation, silicon-phosphorus (SiPx) anodes still suffer from similar capacity degradation issues as pure silicon anodes.

In the present work, we attempt to address the capacity degradation issue by using a thin, conformal carbon coating to modify the solid-electrolyte interface (SEI) reaction. Firstly, amorphous nanoparticles of SiPx with a few atomic percent of phosphorus are prepared using silane and phosphine co-pyrolysis. Using an oscillating furnace at 800 degrees Celsius under a low flow of acetylene in Ar carrier gas, we are able to produce consistent, uniform carbon films on nanoparticle agglomerates with select thicknesses between 2 and 10 nm, validated using low voltage scanning transmission electron microscopy (LV-STEM), as shown in Figure 1. By comparing Si- and SiPx-containing anodes in electrochemical half cells, we can reproduce the rate capability results while demonstrating the effect of carbon coating on cycle life and capacity retention. Furthermore, the carbon coating’s effect on volume expansion for Si- and SiPx-containing anodes is studied in situ using an electrochemical dilatometer in half cell configuration.

[1] Y. Domi, H. Usui, M. Shimizu, Y. Kakimoto, H. Sakaguchi, ACS Applied Materials & Interfaces 2016, 8, 7125-7132.

[2] S. Huang, L.-Z. Cheong, D. Wang, C. Shen, ACS Applied Materials & Interfaces 2017, 9, 23672-23678.

[3] F. T. Huld, S. Y. Lai, W. M. Tucho, R. Batmaz, I. T. Jensen, S. Lu, O. E. Eleri, A. Y. Koposov, Z. Yu, F. Lou, ChemistrySelect
2022, 7, e202202857.

Figure 1
Approach for Mitigating Interfacial Degradation in Silicon-Based Electrodes to Enhance Cycling Stability of Lithium-Ion Batteries and Capacitors
Authors: O MinJu , Roh KwangChul
Published: February 2024

The growing demand for high energy density in lithium-ion batteries has led to extensive investigations on silicon negative electrodes. In this study, we propose a novel approach to address the interfacial degradation of electrodes caused by volume expansion during lithium insertion/extraction. The approach involves a sandwich structure consisting of a carbon nanofiber (CNF) undercoating electrode and a CNF-coated separator. The CNF is treated with acid to form carboxyl and hydroxyl groups on its surface, which improves the dispersion of the coating slurry and enhances adhesion to the electrode. Through electrochemical testing, the improved silicon electrode shows a high retention rate of 82% compared to the initial capacity after 100 cycles, and high electrochemical performance when applied to both lithium-ion batteries and lithium-ion capacitors. These results are attributed to the improved adhesion between the electrode and current collector, as well as the formation of a stable solid electrolyte interphase layer on the electrode surface. These findings suggest that the conductive coating process, applied to the separator and current collector, effectively mitigates interfacial issues that are associated with silicon-based electrodes. This approach has the potential to overcome the degradation characteristics of silicon electrodes and significantly contribute to improving the cycling stability of lithium-ion batteries and capacitors.
Influence of Binders on Printability and Battery Performance of Thick 3D-Printed Positive Electrode for Li-Ion Batteries
Authors: Nguyen Tu T.T. , Sallard Sébastien , Rangasamy Vijay , Hardy An , Safari Mohammadhosein , Lefevere Jasper
Published: February 2024

Nowadays, lithium-ion batteries have been considered to be the superior commercial batteries in the market, thanks to their high energy density (until ca. 250 Wh/kg at cell level) and low fabrication cost (actually < 0.3 Euro/Wh at cell level). However, due to the recent global push for electrification, there is a constant need to further improve battery performance while minimalizing the cost. Besides the development of new battery materials, engineering the electrodes could be a valid solution to meet such demand. By increasing the electrode thickness to 200 µm, the active material loading in the electrode is expected to increase to over 30 wt%, hence enhancing the energy density and limiting the cost at the cell level. Nevertheless, thick electrodes fabricated by conventional coating methods suffer severely from weak mechanical strength and delamination as well as long and highly-tortuous Li-ion diffusion path, sluggish electrochemical kinetics, and poor charge/discharge rate performance. Recently, great attention has gone to 3D printing (additive manufacturing) with the promise to overcome these limitations, thanks to the porous structures of the 3D- printed electrodes.

In this work, we present 450 µm thick lithium iron phosphate (LFP) electrodes produced by 3D micro-extrusion with a superior LFP loading of ca. 30 mg/cm2 and a high areal capacity of ca. 4.2 mAh/cm2. Two commercial polymeric binders were employed, including carboxymethyl cellulose (CMC) and poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS). It is concluded that both CMC and PEDOT:PSS are essential to obtain well-printed 3D electrodes. While CMC contributes significantly to the mechanical strength of the 3D-printed LFP electrodes, it is of great importance to add PEDOT:PSS to avoid intra-fiber cracks. Furthermore, the electrodes containing both binders have shown significantly improved specific capacity at different C-rates compared to those formulated from either CMC or PEDOT:PSS. Further analyses give insights into charge transfer resistance, tortuosity and electrical conductivity of the investigated electrodes. Additionally, we highlight the difference in the battery performance of 3D-printed electrodes and their standard doctor-bladed counterparts.

Reference

(1) Kuang, Y.; Chen, C.; Kirsch, D.; Hu, L. Thick Electrode Batteries: Principles, Opportunities, and Challenges. Adv. Energy Mater.
2019, 9 (33), 1901457. https://doi.org/10.1002/aenm.201901457.
Ultrafast Laser Patterning of Silicon/Graphite Composite Electrodes to Boost Battery Performance
Authors: Meyer Alexandra , Pfleging Wilhelm
Published: February 2024

The ever-increasing share of electric vehicles in the mobility sector urgently calls for an increase in the production capacity of high-power and high-energy lithium-ion batteries with low production costs. A gravimetric energy density of about 350 Wh/kg flanked by a volumetric energy densities of at least 750 Wh/L were defined as ambitious goals from the European Union to be achieved by 2025. For this purpose, novel, high-capacity anode materials containing significant silicon content should be utilized in next generation batteries. At room temperature, silicon has a theoretical specific capacity of 3579 mAh/g which is one order of magnitude higher compared to the state-of-the-art graphite anode material (372 mAh/g). The volume change which silicon undergoes during lithiation and delithiation and the thereby caused mechanical stresses inside the composite electrode, which lead to loss of electrical contact and delamination, are an obstacle for its implementation in industrial battery production. While many researchers focus on other promising approaches to facilitate the usage of silicon in electrodes, for example pre-lithiation, the usage of graphite-silicon composites, or carbon coating on the silicon particles, here, the implementation of additional porosity via laser patterning is pursued. A water-based silicon/graphite slurry concept for the large-scale electrode production is used. There, the silicon nanoparticles’ agglomerates are destroyed and the silicon is finely dispersed using a ball mill, while the slurry homogenization is finalized using a disk stirrer. This facilitates the production of electrode sheets on a roll-to-roll coater, delivering enough material for the high power, high repetition rate roll-to-roll laser patterning process, both of which exhibit a technology readiness level of 5 to 6. The slurry and electrode characterizations are performed using laser induced breakdown spectroscopy (LIBS) for both the binder and lithium spatial distribution, the cyclability and lifetime of the electrodes is assessed in pouch cells with NMC 622 as counter electrode, and the lithiation of the composite material is determined with cyclic voltammetry. Scanning electron, digital and light microscopy are used for the characterization of the laser patterning, while chemical analysis is used to assess the composition of the electrode and the silicon oxidation during water-based manufacturing.
All Dry in One Step (ADIOS to Water) Synthesis of W-Coated Li1+X(Ni0.7Mn0.3)1-XO2
Authors: Yu Svena , Zhang Ning , Garayt Matthew D. L. , Leslie Kate , Yang Chongyin , Dahn Jeff R.
Published: February 2024

Cathode powders for lithium-ion batteries are typically made from hydroxide precursors with the intended transition metal composition and calcined with a lithium source at high temperatures to make LiMO2, where M = Ni, Mn, Co. However, large amounts of process water and salts like NaOH are used in the co-precipitation process employed to make these hydroxide precursors1. Purifying and drying the precursors after co-precipitation requires additional energy input and produces waste streams that are difficult to treat, as illustrated in Fig. 1a. In this work, we introduce a simple, solvent-free method to produce tungsten (W) coated Li1+x(Ni0.7Mn0.3)1-xO2 (NM73) materials from a mixture of Ni, MnO2, LiOH·H2O and W precursors. NM73 was chosen as the primary focus of investigation so that cobalt is avoided due to its scarcity and high cost.

The starting reagents are dry mixed and calcined, followed by jet-milling. An extra reheating step after jet-milling is advantageous for minimizing cation disorder and lithium surface impurities. Pure phase, R -3m single crystal NM73 materials can be made with this method and Rietveld refinement analysis showed that low Ni/Li mixing was achieved. W is believed to remain at the surface, forming a separate LixWyOz phase2. The addition of W was found to reduce the mean particle size and improve both the initial discharge capacity and first cycle efficiency. Small amounts of W increase the initial discharge capacity up to 197 mAh/g. Full coin cells were made from both coated and uncoated materials. Their cycling performance is shown in Fig. 1b, revealing improved capacity retention as another improvement afforded by the W coating.

The proposed method simplifies the current production process of LiMO2 by eliminating the need for hydroxide precursors entirely. Cobalt-free single crystal materials with excellent electrochemical performance can be made all-dry in one step, potentially reducing the cost of cathode materials significantly and eliminating waste streams.

References:

Ahmed Shabbir et al 2017 Power Sources
342, 733–740

Divya Rathore et al2021 Electrochem. Soc.
168 120514

Figure 1. (a) Typical industrial co-precipitation process flow with input and output streams for each step. The red box represents the steps in the ADIOS process and inputs specific to the process are shown in red. (b) Full coin cell cycling from 3 — 4.3V, C/5 rate used. N:P ratio of 1.1 and no anode overhang used. Electrolyte used is 1.5M LiPF6, 25:5:70 EC:EMC:DMC, 2% VC + 1% DTD. The top graph shows the specific capacity vs. cycle number up to the 100th cycle. The bottom graph shows the voltage (vs. Li) vs. specific capacity of the first cycle at C/20 rate from 3 — 4.4 V in half coin cells with lithium metal as the anode. Electrolyte used is 1.2M LiPF6, 1:4 FEC:DMC. Both full and half coin cells were cycled at 30 ˚C.

Figure 1
Synthesis of LiNi1/3Mn1/3Fe1/3O2 as an Intended Cathode Material for Li-Ion Battery
Authors: Patel Roma , Mishra Atul
Published: February 2024

In the present work, we report the synthesis and characterization of LiNi1/3Mn1/3Fe1/3O2 as cathode material for Li-ion batteries. LiNi1/3Mn1/3Fe1/3O2 was synthesized using a very simple and low-cost sol-gel method and subsequent annealing treatment. The Structural, morphological, and electrochemical performance of the synthesized materials is investigated using X-ray diffraction (XRD), Raman spectroscopy, Field Emission Scanning Electron microscopy (FE-SEM), Cyclic voltammetry (CV), Galvanostatic Charge-Discharge (GCD) and Electrochemical Impedance spectroscopy (EIS), respectively. The XRD results revealed the formation of layer structure with a pure α-NaFeO2 hexagonal phase, space group R3¯m. Moreover, these results show negligible cation mixing, which suggests well order layer structure. Raman spectrum of the synthesized sample shows structural fingerprints at 609 and 503 cm-1, which also confirms the R3¯m space group. Raman results support the XRD results. The non-uniform microsphere-like morphology with an average particle size of around 200-300 nm was revealed using FE-SEM. The electrochemical properties of the synthesized products were evaluated in rechargeable Li-ion half cells using a non-aqueous organic electrolyte (1 M LiPO4). The cyclic voltammetry shows that redox reactions occur at the surface of the electrode, which is attributed to Mn3+/Mn4+ and Fe3+/Fe4+. The EIS of LiNi1/3Mn1/3Fe1/3O2 exhibits a lower charge transfer resistance, which indicates a shorter path to move the ions. Further, the electrochemical performance of the synthesized material will be discussed in detail.
High-Performance Ni-Rich Li[Ni0.92−XCo0.04Mn0.04Alx]O2 Cathodes for High Energy Density Lithium-Ion Batteries
Authors: Lee Soo-Been , Lee Han Uk , Sun Yang-Kook
Published: February 2024

A high-performing Ni-rich Li[Ni1−x−y−zCoxMnyAlz]O2 (NCMA) is developed by comparing the electrochemical performance of Li[Ni0.92−xCo0.04Mn0.04Alx]O2 cathodes (x = 0, 0.01, 0.03, and 0.05). Excessive Al leads to the accumulation of Al on secondary particle surfaces and at grain boundaries, resulting in the refinement of the cathode microstructure. Increasing the Al content enhances the degree of refinement, including primary particle elongation and radial alignment. A well-refined microstructure effectively dissipates the strain caused by the rapid contraction of unit cells during the H2 phase → H3 phase transition near the charge end, thereby suppressing the formation of internal cracks. An Al content of 3 mol% provides optimal overall electrochemical performance. The full cell with an optimized Li[Ni0.894Co0.041Mn0.034Al0.031]O2 cathode exhibits excellent long-term cycling stability, retaining >90% of its initial capacity after 500 cycles and an energy density of 740 Wh Kg-1. In contrast, a Li[Ni0.91Co0.04Mn0.04Al0.01]O2 cathode, in which Li and Ni cation mixing is prevented, loses 38.3% of its initial capacity after 500 cycles. This research demonstrates that an NCMA cathode with the optimal Al content can surpass existing layered cathodes and represents a new class of Ni-rich layered cathodes suitable for high-performance electric vehicles.
Versatile High-Valent Doping Strategy for Cathodes with Extremely High Ni Content
Authors: Park Nam-Yung , Lee Sin Gyu , Sun Yang-Kook
Published: February 2024

Currently, battery electric vehicles (BEVs) face significant challenges, such as shorter driving ranges than ICEVs and higher initial costs compared to ICEVs. As the performance and cost of Li-ion batteries (LIBs), that is, the core components of BEV, are mostly determined by the cathode material, automotive manufacturers are currently devoting improvements in energy density and lowering the cost of cathode materials. Ni-rich LiMO2 (M = Ni, Co, Mn, or Al) is a promising cathode material owing to its neartheoretical specific capacity and relatively low content of expensive cobalt. However, a high fraction of reactive Ni4+ ions at the cathode–electrolyte interfaces lead to capacity fading of Ni-rich cathodes.1,2 Therefore, a core–shell (CS) design encapsulating the Ni-rich region by a Ni-less shell is an effective approach for improving the cycling stability of the cathodes.3 However, with increasing average Ni content to increase the capacity, the thickness of the shell should be reduced or the Ni fraction of the shell will be inevitably higher, making it susceptible to interdiffusion, which flattens the concentration gradient during the lithiation process.4

Herein, the limit of the average Ni composition in the CS-type cathode is pushed to 94% via Ta doping, which suppresses interdiffusion by segregating the Ta-rich phases at the particle boundaries. Ta doping allows the maintenance of the highly aligned microstructure and the ordered intermixing structure of Li and transition metal ions, as well as the concentration gradient, over a wide lithiation temperature range. The Ta-doped CS-type cathode retains 92.6% of its initial capacity after 1000 cycles and exhibits resistance to damage from fast charging. Multifunctional Ta doping in the CS-type cathode provides a simple and all-around solution to maximize the electrochemical performance of Ni-rich cathodes, providing flexibility in the lithiation process.

Reference
s
:

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

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

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

[4] G.-T. Park, H.-H. Ryu, T.-C. Noh, G.-C. Kang, Y.-K. Sun, Mater. Today
2022, 52, 9.
Compositionally Partitioned Li[Ni0.9Mn0.1]O2 Cathode That Affords Fast-Charging Lithium-Ion Batteries
Authors: Park Geontae , Ryu Ji-Hyun , Sun Yang-Kook
Published: February 2024

The development of Co-free Li[NixMn1−x]O2 cathodes for lithium-ion batteries (LIBs) that can supersede Co-containing Li[NixCoyMn1−x−y]O2 and Li[NixCoyAl1−x−y]O2 cathodes is considered a priority as Co is associated with price volatility, environmental concerns, and human rights violations.1,2 In this study, a morphology-engineering approach is used to develop a Co-free Li[Ni0.9Mn0.1]O2 cathode with a Ni-rich core–Mn-rich shell structure to overcome the limitations of Co-free Li[NixMn1−x]O2 cathodes. The engineered morphology of the Co-free Li[Ni0.9Mn0.1]O2 cathode particles effectively dissipates internal strain caused by state-of-charge heterogeneity and fracture toughening the cathode. the Co-free cathode demonstrates excellent long-term cycling stability; it retains 78.5% of its initial capacity after 2000 cycles at 1 C charge and 0.8 C discharge rates, and retains an unprecedented 79.5% after 1000 cycles under fast-charging conditions (3 C charge and 1 C discharge). The proposed Co-free layered oxide cathode represents a next-generation cathode that affords fast-charging and durable LIBs, which are more cost effective than LIBs featuring commercial Co-containing cathodes.

Reference
s
:

[1] A. Aishova, G.-T. Park, C. S. Yoon, Y.-K. Sun, Adv. Energy Mater. 10 (2019) 1903179..

[2] G.-T. Park, B. Namkoong, S.-B. Kim, J. Liu, C. S. Yoon, Y.-K. Sun, Nat. Energy 7 (2022) 946.
Doping Strategy to Improve the Electrochemical Behavior of Lithium Rich Transition Metal Oxides As Cathodes for Lithium-Ion Batteries
Authors: Celeste Arcangelo , Tuccillo Mariarosaria , Silvestri Laura , Brutti Sergio
Published: February 2024

Lithium-rich transition metal oxides are considered a promising cathodic solutions in Li-ion batteries to meet the growing energetic demand, thanks to their high specific capacity and operational voltage [1-2]. Li-rich layered materials have a general stoichiometry Li1+xTM1-xO2, in which TM is a blend of transition metals, as Ni, Mn, Co [2]. They stand out due to their high lithium concentration and specific capacity [1-2]. The higher capacity of Lithium-Rich can be attributed to the specific anionic redox reaction in the bulk at above 4.5 V. Nevertheless, large irreversible capacity loss in the first cycle, poor rate capability, mean working potential decay upon cycling and cobalt content are still major drawbacks that are hindering commercialization. In order to make these materials up scalable to industrial production, it is important to consider the reduction of costs and the toxicity of raw materials, in particular cobalt. Cobalt reduction has been identified as major driver to improve the environmental benignity of batteries and the sustainability of the overall production-consumption-recycling lifecycle. Several efforts to reduce these problems have been made, including the development of different synthetic strategies, doping and surface modification. The most, widely explored, chemical strategy to mitigate the voltage decay and structural degradation in Lithium Rich cathodes is the doping. Elemental doping can be divided into cation and anion doping. As an example, incorporation of redox inactive metals, such as Al, Zr, Ti, has been proposed in order to stabilize the lattice as well as the partial replacement of lithium ions with other alkali cations, e.g. K and Na; or doping the oxygen anion sublattice. In this communication, we present our doping approaches. In particular, the simultaneous replacement of cobalt in the layered structure with aluminum and lithium (over-lithiation). Moreover, we present over-lithiated Co-free materials where the introduction of different amount of iron has been investigated. The characterization of these novel layered materials is reported in terms of composition, structure, morphology and electrochemical performances. These approaches can be applied as a strategy to mitigate the voltage decay and reduce the Cobalt content.

[1] Ji, X. et al. Journal of Power Sources 487, (2021).

[2] Zhao, S. et al. Angewandte Chemie - International Edition 60, 2208–2220 (2021).
Minimizing Carbon Content in Thiophosphate-Based Composite Cathodes for All-Solid-State Batteries
Authors: Reisacher Elias , Kaya Pinar , Knoblauch Volker
Published: February 2024

To achieve high energy densities with sufficient cycling performance in all-solid-state batteries (ASSBs), the fraction of active material has to be maximized while maintaining ionic and electronic conduction throughout the composite cathode. In a previous study, C65 added to the composite-cathode showed the potential to enhance the capacity and rate capability [1]. In contrast, it is known that carbon additives can lead to faster decomposition of the cathode constituents in thiophosphate-based cells [2]. By determining the electronic percolation threshold of the conducting matrix (CM), the C65 fraction shall be minimized. As a result, not only side reactions could be suppressed, but also the amount of AM and SE can be kept as high as possible [3,4]. Additionally, the role of the CM is discussed with respect to active material coatings, which are used to enhance electrochemically stability in thiophosphate-based ASSBs [5,6].

In this study, we systematically investigated the microstructure and the conductive behaviour of a CM containing the sulfide solid electrolyte (SE) Li6PS5Cl and various fractions of C65. The effective conductivity of the different compositions was determined by temperature depended electrochemical impedance spectroscopy (EIS) and the effective conductivity was calculated as a function of temperature and C65 content. The electronic percolation threshold pc
was determined to be about 4 wt.-% C65. It is suggested that below pc, the ionic contribution is dominant, which can be seen from the temperature dependency of the conductivity and blocked charge transfer. Above, the impedance of the CM becomes frequency-independent, and the ohmic law applies. In order to differentiate between electronic and ionic charge transport, the powder mixtures near pc
were additionally investigated in electron-blocking condition. Furthermore, the adjusted CM was used in composite-cathodes, and rate capability behaviour, as well as the cycling performance of the ASSB cells, was evaluated.

Acknowledgement

The authors gratefully acknowledge the support of the German Federal Ministry of Education and Research within the program “FH‐Impuls” (Project SmartPro, Subproject SMART‐BAT, Grant no. 13FH4I07IA), Nikolaos Papadopoulos and Dr. Veit Steinbauer (Aalen University).

References

[1] Florian Strauss et al., RSC Adv., 2020, 10, 1114.

[2] Wenbo Zhang et al., ACS applied materials & interfaces, 2017, 41, 35888.

[3] Yuki Kato et al., J. Phys. Chem. Lett., 2018, 9, 607.

[4] Georg Dewald et al., Batteries & Supercaps, 2021, 4, 183.

[5] Xuelei Li et al., J. Eng. Chem., 2020, 40, 39.

[6] Felix Walther et al., Chemistry of Materials, 2021, 33, 2110.
Factors Affecting Performance of Single-Crystal Nickel-Rich Layered Oxides Cathode
Authors: Fung Kuan-Zong , Tsai Shu-Yi , Fung Kenneth , Chen Yu-Hsuan , Yang Jen-Hao , Chang Chia-Chin
Published: February 2024

For the past decades, multi-element layered oxide such as Li(Ni,Co,Mn)O2 has been processed by a very popular co-precipitation method. Recently, layered oxides obtained by a single-crystal process has received great attention. The oxides prepared by co-precipitation typically show very uniform and fine particles in nm range <500nm. However, very fine co-precipitated oxide particles with large specific area may suffer from reaction with liquid electrolyte. When the grain size of Ni-rich layered oxides reaches µm range, they tend to show better cycling performance with better structural integrity and less volume change during charge/discharge cycles. Toward the formation of single crystal Ni-rich layered oxides, it may involve decomposition, chemical reactions, diffusion, oxidation, sintering, grain-growth. As a result, factors such as temperature, annealing period and atmospheres may be critical for high-performance cathode. Thus, the objective of this study is (1) to identify what are key factors; (2) the role of key factors; (3) optimization of key factors for better performance. For factor verification and understanding of single crystal process, the resulted electrical, optical, structural, and electrochemical properties of layered oxides will be analyzed and discussed based on defect chemistry consideration. During the different stages of processing, the structural, microstructural and electrical properties of decomposed precursors and resultant layered oxides will be examined using XRD, SEM and DC/AC impedance measurements. CV and charge/discharge tests from assembled coin cells will be used to evaluate electrochemical properties of single-crystal Ni-rich layered oxides.
Electrospun Perovskite Nanofiber/Poly(vinylidene fluoride-cohexafluoropropylene) Quasi-Solid-State for Lithium-Metal Batteries
Authors: Rath Purna Chandra , Lo Shih-Ting , Lee Sheng-Wei , Chang Jeng-Kuei
Published: February 2024

Solid-state lithium-metal batteries (SSLMBs) with a composite solid electrolyte (CSE) have great potential for achieving both high energy density and high safety and are thus promising next-generation energy storage devices. Nevertheless, the key bottleneck issues are a high electrode/electrolyte interface resistance and the limited Li+ conductivity of the solid electrolyte. A free-standing CSE consisting of Li0.33La0.557TiO3 (LLTO) nanofibers, poly(vinylidene fluoride-co-hexafluoropropylene (PVDF-HFP), and lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) is developed for room-temperature SSLMB applications. First, the calcination temperature for the electrospun LLTO precursor is optimized. The effects of the LLTO filler fraction and the morphology (spherical vs. fibrous) on CSE conductivity are examined. Furthermore, a succinonitrile interlayer (SNI), which is composed of succinonitrile, fluoroethylene carbonate, and LiTFSI, is developed to lower the high interfacial impedance. Compared to a conventional ester-based interlayer (EBI), SNI effectively decreases the Li//CSE interfacial resistance and suppresses unfavorable interfacial side reactions. The derived LiF- and CF
x
-rich protective layer on the Li electrode surface prevents the accumulation of dead Li and the excessive formation of SEI. Importantly, the dehydrofluorination reactions of PVDF-HFP are adequately mitigated, and a highly conductive and stable Li//CSE interface is achieved owing to SNI. Accordingly, both Li//CSE@SNI//Li and Li//CSE@SNI//LiFePO4 cells exhibit superior charge-discharge properties and cyclability to those of an EBI counterpart. A simple and low-cost interface modification strategy to enhance the performance of SSLMBs is proposed in this paper.
Improvement of Ionic Conductivity in Li7La3Zr2O12 (LLZO) Solid Electrolyte By Doping with Aluminum/Tungsten
Authors: Hong Da-been , Park Jae-wan , Shim Jae-Hyun , Kim Moon-Sung
Published: February 2024

Recently, there has been increasing interest in solid electrolytes, which are the most important materials in all-solid-state lithium-ion batteries. Among all solid electrolytes, garnet-type Li7La3Zr2O12 (LLZO) has been proven to be one of the most promising electrolytes due to its high Li+ conductivity, wide potential window, and electrochemical stability towards metallic lithium anode. In particular, cubic garnet-type LLZO solid electrolytes have received a lot of attention for the development of high-performance all-solid-state batteries with safety, energy density, and long cycle life. In this study, we synthesized LLZO solid electrolyte powders with garnet structure and determined the optimal composition and sintering temperature by adding Al/W to form a stable cubic phase.

In this study, Al or W-doped LLZO were prepared by a post-doping method. In this process, LLZO powder was first prepared, and then mixed with Al2O3 or WO3 powders to produce doped LLZO ceramic electrolytes, respectively. During this process, the doped ions entered the LLZO lattice, increasing the lithium ion transport channels and promoting lithium ion conductivity. The sintering time, crucible, and sintering temperature were adjusted to investigate the optimal process conditions of the post-doping method. As a result, the doped solid electrolyte exhibited high lithium ion conductivity and low activation energy. Using the high lithium ion conductivity and broad electrochemical stability window of the Al or W doped LLZO SSE, the (NCM622)/(Al or W doped-LLZO) cell delivered a steady cycle for 100 cycles at 0.1C. The Al or W doped-LLZO prepared in this study showed advantages of high conductivity, simple preparation process, high reproducibility, and low cost, which provides technical support and reference for further application of garnet-type SSEs in solid-state batteries with high energy density.