Characterization and Laser Structuring of Aqueous Processed Li(Ni0.6Mn0.2Co0.2)O2 Thick-Film Cathodes for Lithium-Ion Batteries

Lithium-ion batteries have led the revolution in portable electronic devices and electrical vehicles due to their high gravimetric energy density. In particular, layered cathode material Li(Ni0.6Mn0.2Co0.2)O2 (NMC 622) can deliver high specific capacities of about 180 mAh/g. However, traditional cathode manufacturing involves high processing costs and environmental issues due to the use of organic binder polyvinylidenfluoride (PVDF) and highly toxic solvent N-methyl-pyrrolidone (NMP). In order to overcome these drawbacks, aqueous processing of thick-film NMC 622 cathodes was studied using carboxymethyl cellulose and fluorine acrylic hybrid latex as binders. Acetic acid was added during the mixing process to obtain slurries with pH values varying from 7.4 to 12.1. The electrode films could be produced with high homogeneity using slurries with pH values smaller than 10. Cyclic voltammetry measurements showed that the addition of acetic acid did not affect the redox reaction of active material during charging and discharging. Rate capability tests revealed that the specific capacities with higher slurry pH values were increased at C-rates above C/5. Cells with laser structured thick-film electrodes showed an increase in capacity by 40 mAh/g in comparison to cells with unstructured electrodes.

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The Ultrafast Laser Ablation of Li(Ni0.6Mn0.2Co0.2)O2 Electrodes with High Mass Loading

Applied Sciences ◽

10.3390/app9194067 ◽

2019 ◽

Vol 9 (19) ◽

pp. 4067 ◽

Cited By ~ 3

Author(s):

Penghui Zhu ◽

Hans Jürgen Seifert ◽

Wilhelm Pfleging

Keyword(s):

Energy Density ◽

Lithium Ion Batteries ◽

Thick Film ◽

Power Density ◽

Discharge Capacity ◽

Rate Capability ◽

Lithium Ion ◽

Ultrafast Laser ◽

High Mass ◽

Simultaneous Increase

Lithium-ion batteries have become the most promising energy storage devices in recent years. However, the simultaneous increase of energy density and power density is still a huge challenge. Ultrafast laser structuring of electrodes is feasible to increase power density of lithium-ion batteries by improving the lithium-ion diffusion kinetics. The influences of laser processing pattern and film thickness on the rate capability and energy density were investigated using Li(Ni0.6Mn0.2Co0.2)O2 (NMC 622) as cathode material. NMC 622 electrodes with thicknesses from 91 µm to 250 µm were prepared, while line patterns with pitch distances varying from 200 µm to 600 µm were applied. The NMC 622 cathodes were assembled opposing lithium using coin cell design. Cells with structured, 91 µm thick film cathodes showed lesser capacity losses with C-rates 3C compared to cells with unstructured cathode. Cells with 250 µm thick film cathode showed higher discharge capacity with low C-rates of up to C/5, and the structured cathodes showed higher discharge capacity, with C-rates of up to 1C. However, the discharge capacity deteriorated with higher C-rate. An appropriate choice of laser generated patterns and electrode thickness depends on the requested battery application scenario; i.e., charge/discharge rate and specific/volumetric energy density.

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Utilizing the Intrinsic Thermal Instability of Swedenborgite Structured YBaCo4O7+δ as an Opportunity for Material Engineering in Lithium-Ion Batteries by Er and Ga Co-Doping Processes

Materials ◽

10.3390/ma14164565 ◽

2021 ◽

Vol 14 (16) ◽

pp. 4565

Author(s):

Sanghyuk Park ◽

Kwangho Park ◽

Ji-Seop Shin ◽

Gyeongbin Ko ◽

Wooseok Kim ◽

...

Keyword(s):

Lithium Ion Batteries ◽

Phase Stability ◽

Electrochemical Impedance ◽

Coulombic Efficiency ◽

Structural Phase ◽

Active Material ◽

Rate Capability ◽

Lithium Ion ◽

Ion Migration ◽

Co Doping

We firstly introduce Er and Ga co-doped swedenborgite-structured YBaCo4O7+δ (YBC) as a cathode-active material in lithium-ion batteries (LIBs), aiming at converting the phase instability of YBC at high temperatures into a strategic way of enhancing the structural stability of layered cathode-active materials. Our recent publication reported that Y0.8Er0.2BaCo3.2Ga0.8O7+δ (YEBCG) showed excellent phase stability compared to YBC in a fuel cell operating condition. By contrast, the feasibility of the LiCoO2 (LCO) phase, which is derived from swedenborgite-structured YBC-based materials, as a LIB cathode-active material is investigated and the effects of co-doping with the Er and Ga ions on the structural and electrochemical properties of Li-intercalated YBC are systemically studied. The intrinsic swedenborgite structure of YBC-based materials with tetrahedrally coordinated Co2+/Co3+ are partially transformed into octahedrally coordinated Co3+, resulting in the formation of an LCO layered structure with a space group of R-3m that can work as a Li-ion migration path. Li-intercalated YEBCG (Li[YEBCG]) shows effective suppression of structural phase transition during cycling, leading to the enhancement of LIB performance in Coulombic efficiency, capacity retention, and rate capability. The galvanostatic intermittent titration technique, cyclic voltammetry and electrochemical impedance spectroscopy are performed to elucidate the enhanced phase stability of Li[YEBCG].

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Effect of Fluence and Multi-Pass on Groove Morphology and Process Efficiency of Laser Structuring for 3D Electrodes of Lithium-Ion Batteries

Materials ◽

10.3390/ma14051283 ◽

2021 ◽

Vol 14 (5) ◽

pp. 1283

Author(s):

Dongkyu Park ◽

Dongkyoung Lee

Keyword(s):

Lithium Ion Batteries ◽

Morphological Variation ◽

Active Material ◽

Lithium Ion ◽

High Energy ◽

Process Efficiency ◽

Nanosecond Laser ◽

Laser Parameters ◽

Laser Structuring ◽

Number Of Passes

Lithium-ion batteries (LIBs) are widely used as energy storage systems. With the growing interest in electric vehicles, battery performance related to traveling distance has become more important. Therefore, there are various studies going on to achieve high-power and high-energy batteries. Laser structuring of electrodes involves a groove being produced on electrodes by a laser. This technique was used to show that battery performance can be enhanced due to improving Li-ion diffusion. However, there is a lack of studies about the morphological variation of grooves and process efficiency in laser parameters in the laser structuring of electrodes. In this study, the LiFePO4 cathode is structured by a nanosecond laser to analyze the morphological variation of grooves and process efficiency depending on laser fluence and the number of passes. First, the various morphologies of grooves are formed by a combination of fluences and the number of passes. At a fluence of 0.86 J/cm2 and three passes, the maximum aspect ratio of 1.58 is achieved and the surface area of structured electrodes is greater than that of unstructured electrodes. Secondly, three ablation phenomena observed after laser structuring are classified according to laser parameters through SEM images and EDX analysis. Finally, we analyze the amount of active material removal and process efficiency during laser structuring. In conclusion, applying low fluence and multi-pass is assumed to be advantageous for laser structuring of electrodes.

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MoS2 Layers Decorated RGO Composite Prepared by a One-Step High-Temperature Solvothermal Method as Anode for Lithium-Ion Batteries

NANO ◽

10.1142/s1793292018501357 ◽

2018 ◽

Vol 13 (11) ◽

pp. 1850135 ◽

Cited By ~ 2

Author(s):

Xuehua Liu ◽

Bingning Wang ◽

Jine Liu ◽

Zhen Kong ◽

Binghui Xu ◽

...

Keyword(s):

High Temperature ◽

Lithium Ion Batteries ◽

Active Material ◽

Rate Capability ◽

Lithium Ion ◽

Cost Effective ◽

Reversible Capacity ◽

Reduced Graphene ◽

One Step ◽

Anode Active Material

A one-step high-temperature solvothermal approach to the synthesis of monolayer or bilayer MoS2 anchored onto reduced graphene oxide (RGO) sheet (denoted as MoS2/RGO) is described. It was found that single-layered or double-layered MoS2 were synthesized directly without an extra exfoliation step and well dispersed on the surface of crumpled RGO sheets with random orientation. The prepared MoS2/RGO composites delivered a high reversible capacity of 900[Formula: see text]mAhg[Formula: see text] after 200 cycles at a current density of 200[Formula: see text]mAg[Formula: see text] as well as good rate capability as anode active material for lithium ion batteries. This one-step high-temperature hydrothermal strategy provides a simple, cost-effective and eco-friendly way to the fabrication of exfoliated MoS2 layers deposited onto RGO sheets.

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Design Considerations to Improve Transport in Porous Electrodes for Lithium-Ion Batteries

MRS Proceedings ◽

10.1557/opl.2012.1287 ◽

2012 ◽

Vol 1440 ◽

Cited By ~ 1

Author(s):

Rajeswari Chandrasekaran ◽

Andrew Drews ◽

Apoorv Shaligram ◽

Jeffrey Sakamoto

Keyword(s):

Transport Properties ◽

Lithium Ion Batteries ◽

Active Material ◽

Rate Capability ◽

Lithium Ion ◽

Porous Electrodes ◽

Design Considerations ◽

Lithium Ion Cells ◽

Effective Transport ◽

The Relationship

ABSTRACTThe relationship between tortuosity and porosity and its influence on effective transport properties in lithium-ion cells was analyzed. The variation in cell performance with changes in component thicknesses, porosities and tortuosities was investigated. Optimal, novel electrode designs are developed to improve their rate capability even at higher active material loadings.

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Excellent rate capability and cycling stability in Li+-conductive Li2SnO3-coated LiNi0.5Mn1.5O4 cathode materials for lithium-ion batteries

Dalton Transactions ◽

10.1039/c8dt00014j ◽

2018 ◽

Vol 47 (20) ◽

pp. 7020-7028 ◽

Cited By ~ 24

Author(s):

Jirong Mou ◽

Yunlong Deng ◽

Zhicui Song ◽

Qiaoji Zheng ◽

Kwok Ho Lam ◽

...

Keyword(s):

Energy Density ◽

Lithium Ion Batteries ◽

Power Density ◽

High Voltage ◽

Cathode Materials ◽

Active Material ◽

Rate Capability ◽

Lithium Ion ◽

Side Reactions ◽

Capacity Fading

High-voltage LiNi0.5Mn1.5O4 is a promising cathode candidate for lithium-ion batteries (LIBs) due to its considerable energy density and power density, but the material generally undergoes serious capacity fading caused by side reactions between the active material and organic electrolyte.

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Soft-templated LiFePO4/mesoporous carbon nanosheets (LFP/meso-CNSs) nanocomposite as the cathode material of lithium ion batteries

RSC Advances ◽

10.1039/c4ra00370e ◽

2014 ◽

Vol 4 (41) ◽

pp. 21325-21331 ◽

Cited By ~ 9

Author(s):

Ruofei Wu ◽

Guofeng Xia ◽

Shuiyun Shen ◽

Fengjuan Zhu ◽

Fengjing Jiang ◽

...

Keyword(s):

Lithium Ion Batteries ◽

Mesoporous Carbon ◽

Electronic Conductivity ◽

Active Material ◽

Rate Capability ◽

Lithium Ion ◽

High Rate ◽

Carbon Nanosheets ◽

High Electronic Conductivity ◽

Nano Size

A soft-templated LFP/mesoporous carbon nanosheets (LFP/meso-CNSs) nanocomposite as the cathode of lithium ion batteries displays an excellent high-rate capability and stable cycling property, benefitting from its high electronic conductivity, open mesoporosity, and the nano-size of its active material.

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Porous Polymer Gel Electrolytes Influence Lithium Transference Number and Cycling in Lithium-Ion Batteries

Electronic Materials ◽

10.3390/electronicmat2020013 ◽

2021 ◽

Vol 2 (2) ◽

pp. 154-173

Author(s):

Buket Boz ◽

Hunter O. Ford ◽

Alberto Salvadori ◽

Jennifer L. Schaefer

Keyword(s):

Transport Properties ◽

Lithium Ion Batteries ◽

Polymer Electrolyte ◽

Active Material ◽

Polymer Network ◽

Rate Capability ◽

Lithium Ion ◽

Transference Number ◽

Porous Polymer ◽

Performance Property

To improve the energy density of lithium-ion batteries, the development of advanced electrolytes with enhanced transport properties is highly important. Here, we show that by confining the conventional electrolyte (1 M LiPF6 in EC-DEC) in a microporous polymer network, the cation transference number increases to 0.79 while maintaining an ionic conductivity on the order of 10−3 S cm−1. By comparison, a non-porous, condensed polymer electrolyte of the same chemistry has a lower transference number and conductivity, of 0.65 and 7.6 × 10−4 S cm−1, respectively. Within Li-metal/LiFePO4 cells, the improved transport properties of the porous polymer electrolyte enable substantial performance enhancements compared to a commercial separator in terms of rate capability, capacity retention, active material utilization, and efficiency. These results highlight the importance of polymer electrolyte structure–performance property relationships and help guide the future engineering of better materials.

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