bluuebunny/crossref_metadata_2025_split huggingface dataset:
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
(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
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.
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
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.