Cellulose Binder Research Articles

Influence of a carboxymethyl cellulose (CMC) binder on the mechanical properties of iron ore pellets

This paper is based on project work carried out in partial fulfillment of a BEng (Metallurgical Engineering) degree at the University of Pretoria.

Carboxymethyl cellulose binders enable high-rate capability of sulfurized polyacrylonitrile cathodes for Li–S batteries

Water-processable binders improved the electrode polarity and wettability. Li–S batteries consisting of such binders exhibited superior performance at high current densities.

High performance polymer binders inspired by chemical finishing of textiles for silicon anodes in lithium ion batteries

Inspired by the chemical finishing method for textile, theN-methylol acrylamide functionalized carboxymethyl cellulose binder has been developed for Si anodes. This binder can help maintain integration of the Si electrodes, leading to significant improvement in cycling performance of the Si based lithium ion batteries.

Graphite//LiNi0.5 Mn1.5 O4 Cells Based on Environmentally Friendly Made-in-Water Electrodes.

The performance of graphite//LiNi0.5 Mn1.5 O4 (LNMO) cells, both electrodes of which are made using water-soluble sodium carboxymethyl cellulose (CMC) binder, is reported for the first time. The full cell performed outstandingly over 400 cycles in the conventional electrolyte ethylene carbonate/dimethyl carbonate-1 m LiPF6 , and the delivered specific energy at the 100th, 200th, 300th, and 400th cycle corresponded to 82, 78, 73, and 66 %, respectively, of the initial energy value of 259 Wh kg-1 (referring to the sum of the two electrode-composite weights). The good stability of high-voltage, LNMO-CMC-based electrodes upon long-term cycling is discussed and the results are compared to those of LNMO-composite electrodes with polyvinylidene fluoride (PVdF). LNMO-CMC electrodes outperformed those with PVdF binder, displaying a capacity retention of 83 % compared to 62 % for the PVdF-based electrodes after 400 cycles at 1 C. CMC promotes a more compact and stable electrode surface than PVdF; undesired interfacial reactions at high operating voltages are mitigated, and the thickness of the passivation layer on the LNMO surface is reduced, thereby enhancing its cycling stability.

Fabrication of electrically conductive substrates using copper nanoparticles-deposited carbon black

Carbon black particles surrounded by copper nanoparticles (Cu NPs) were synthesized using electroless plating method. Palladium chloride was adsorbed onto carbon black, followed by the reduction of palladium chloride for catalyzing the reduction of Cu ions on the surface of carbon black particles. After that, carbon black particles doped by palladium catalyst were dispersed and stirred in Cu plating bath. Cu ions being reduced, Cu NPs surrounded the surface of carbon black particles (Cu@CB). The ratios of Cu to carbon black were controlled through variation of weight of Cu ions in Cu plating bath from 1:1 to 1:7. Cu@CB was applied to electrically conductive substrates with ethyl cellulose binder. Electrical properties and morphology were measured and compared with different weight ratio of Cu and carbon black. It was found that when weight ratio of Cu to carbon black was above three, resistivity of conductive substrates fabricated decreased dramatically. Lowest resistivity was 5.93 × 10−4 Ωcm, confirming the advantages of Cu@CB which has possibility of lowering weight percentage of metal in conductive substrates through simple process.

Effects and Mechanisms of Binders on the Properities of Magnesium Oxide Pellets

The physical characteristics of MgO pellets prepared with different amounts of sodium carboxymethyl cellulose binder or polyvinyl alcohol binder were studied by the compression strength test, drop test, and porosity test. The strength of the pellets increased, while the pellet porosity decreased, with higher binder content. Phase composition, microstructure, and thermal stability of the MgO pellets were investigated using x-ray diffraction, scanning electron microcopy, and thermogravimetric analysis, respectively. The binding mechanism of sodium carboxymethyl cellulose in the MgO pellets was investigated by infrared spectroscopy and x-ray photoelectron spectroscopy.

Effect of Carboxymethyl Cellulose Binder on the Quality of Biomass Pellets

Quality and energy efficiency are two critical concerns associated with the production of biomass pellets. This study elaborates methods to improve the quality of biomass pellets by using a new additive solution (carboxymethyl cellulose (CMC)) and its influence on pellet physical and mechanical properties during the densification of three types of agricultural waste (cotton stalks, wheat straw, and rape straw). Simultaneously, the cohesion and binding mechanisms were analyzed with attenuated total reflectance infrared spectra (ATR-FTIR) and light microscopy (LM). The results show that adding CMC lowers the energy consumption and increases the pellet quality by improving relaxed density, compressive strength, and durability for cotton stalks and wheat straw. However, adding CMC to rape straw decreased the pellet quality. Our results showed that addition of CMC leads to electrostatic forces among the particles that might be responsible for the cohesion strength of biomass pellets, which may be attributed to...

Insights from Studying the Origins of Reversible and Irreversible Capacities on Silicon Electrodes

Coulombic efficiency (CE) of a lithium-ion battery (LIB) anode is a measure of the charge capacity over discharge capacity for a given cycle. A low CE is not a major issue for half cell tests, where there is plenty of lithium in the counter electrode. However, full cell battery performance can be significantly affected by CE, especially the first cycle efficiency. Most battery research attributes the first cycle irreversible capacity to processes such as solid electrolyte interphase (SEI) formation and electrolyte decomposition [1,2]. This, however, does not adequately give a full picture of what is going on in the electrode. A better understanding of the different contributions leading to the reversible and irreversible capacities is necessary in order to suggest strategies for improvements. In this study, we use a systematic approach to separate the charge-discharge capacities of silicon electrodes into different contributions, in particularly SEI formation, lithium accommodation in carbon and binder, and lithiation and delithiation of the active material. This is possible because the three different contributions have different characteristics. Firstly, we note that SEI is typically formed during the first discharge above 0.1V before the lithiation of silicon [3]. So by comparing the CE of electrodes discharged to different capacities, SEI contribution can be identified. Secondly, the lithium accommodation in carbon and binder depends on their amount. So by comparing electrodes with different compositions, this contribution can also be distinguished. The remaining capacity is attributed to the lithiation and delithiation of silicon. The experimental is as follows. Silicon electrodes using commercial silicon particles (Sigma Aldrich), conductive carbon (acetylene black (AB)) and carboxymethyl cellulose (CMC) binder were made with a ratio of 4:3:3, 6:2:2 and 8:1:1. We kept the same ratio between AB and CMC so that the two components can be considered as one. Multiple cells were made, and each of them is initially discharged to different cutoff capacity (250, 500, 1000, 1500, 2000, 2500, 3000 and 3500mAh g-1), and the corresponding charge capacity is recorded. Figure 1a shows a summary of the initial discharge-charge curves of different cells with a composition of 4:3:3. The respective first charge capacity vs. first discharge capacity is summarized in Figure 1b, which shows a linear behavior that is shifted from the origin. The slope of the line corresponds to the intrinsic first cycle efficiency of Si, which is about 90% and is relatively constant regardless of the degree of lithiation. This suggests that no matter how much lithium is initially inserted into the material, 10% of them remains in the lattice and cannot be removed. On the other hand, the x-intercept corresponds to the irreversible capacity of the electrode. About 16 mAh (g Si)-1 can be attributed to SEI formation and electrolyte decomposition in our electrodes. It is interesting to note that despites the use of the same materials, the behavior of the 8:1:1 electrode deviates from those of the other two electrodes at high discharge capacity. Since the only difference is the electrode composition, the behavior is attributed to insufficient mechanical strength of the electrode, which significantly reduces the reversibility of lithium accommodation. So, our method also enables us to identify the onset of mechanical breakdown in the electrode. We have developed a method here to distinguish the different contributions to the overall capacity of silicon. The obtained information is valuable for designing electrode to increase its stability. Further works on the analysis of subsequent cycles, effect of particle surface area and binder type are underway and will be presented at the meeting. Reference: 1) Chen, X., Li, X., Mei, D., Feng, J., Hu, M. Y., Engelhard, M., Zheng, J., Xu, W., Xiao, J., Liu, Jun. & Zhang, J. G. ChemPubSoc. 7, 549-554 (2014). 2) Lin, Y. M., Klavetter, K. C., Abel, P. R., Davy, N. C., Sinder, J. L., Heller, A. & Mullins, B. ChemComm. 48, 7268-7270 (2012). 3) Wang,Z. C., Xu, J., Yao, W. H., Yao, Y. & Yang, W. Y. ECS Trans. 41, 29– 40 (2012). Figure 1

Surfactants as separation modifiers in chemical analyses by thin-layer chromatography: A review

The works reported in the literature (1994–2015) on the use of surfactants as separation modifiers of organic and inorganic compounds by thin-layer chromatography (TLC) is discussed. A number of adsorbents such as silica gel (plain and modified with surfactants and other compounds), stannous silicate, aminoplast, soil, urea-formaldehyde polymer with cellulose binder, and bismuth silicate have been used as layer materials. Surfactants used for the modification of the mobile and stationary phases in TLC have opened new opportunities for realizing novel separations of analytical importance. The salient features of TLC systems used in the analysis of organic and inorganic mixtures of substances have been provided in the tabular form.

Electrochemical properties of large-sized pouch-type lithium ion batteries with bio-inspired organic cathode materials

To investigate the feasibility of scaling up bio-inspired organic materials as cathode materials in lithium ion batteries, large-sized pouch cells are successfully prepared via tape casting using lumichrome with an alloxazine structure and aqueous styrene butadiene rubber-carboxymethyl cellulose (SBR-CMC) binders. A battery module with a two-in-series, six-in-parallel (2S6P) configuration is also successfully fabricated and is able to power blue LEDs (850 mW). Lumichrome shows no structural changes during the fabrication processes used to produce the positive electrode. The large-sized pouch cells show two sets of cathodic and anodic peaks with average potentials of 2.58 V and 2.26 V vs. Li/Li+, respectively. The initial discharge capacities are 142 mAh g−1 and 148 mAh g−1 for ethylene carbonate-dimethyl carbonate (EC-DMC) and tetraethylene glycol dimethyl ether (TEGDME) electrolytes, respectively, similar to that of a coin cell (149 mAh g−1). The EC-DMC-injected pouch cells exhibit higher rate performance and cyclability than the TEGDME-injected ones. The TEGDME electrolyte is not suitable for lithium metal anodes because of electrolyte decomposition and subsequent cell swelling.

Removal of volatile organic compounds over bagasse ash derived activated carbons and monoliths

The unburned carbon in bagasse ash was separated and used as a starting material for activated carbon and carbon monolith preparation. The separated carbon was steam activated in a rotary kiln under different conditions and compared with carbon activated in limited supply of air. The activated carbon from the rotary kiln showed surface areas ranging from 324 to 601m2/g. Different phenolic resins and cellulosic binders were used to prepare the monoliths using slurry casting method. The effects of different preparation conditions on the properties of the monolith were studied. Upon monolith formation, the surface area was reduced slightly and surface areas in the range 92–479m2/g were achieved. The activated carbons and monoliths were tested for static adsorption of volatile organic compounds (VOCs) using benzene, xylene, hexane and toluene as model compounds. With the activated carbons, adsorption capacities as high as 22.5, 31.1, 27.5 and 25.0g/100g sample were obtained for toluene, benzene, xylene and hexane, respectively. The adsorption capacities were reduced for the corresponding monoliths. The waste derived activated carbons and monoliths show promising results as adsorbents for the removal of volatile organic compounds.

Hyperpolarized129Xe Nuclear Magnetic Resonance Studies of Si Nanocomposite Electrode Materials

Porosity and interconnectivity of pores play an important role in the performance of composite electrodes in Li ion batteries. Hyperpolarized (HP) 129Xe nuclear magnetic resonance (NMR) is powerful for probing porosity and interconnectivity of nanopores. This study represents the first time that temperature-dependent HP 129Xe NMR has been successfully applied to explore the pore structure and interconnectivity in composite electrodes made of nano Si powder, super P carbon, and sodium carboxyl methyl cellulose (CMC) binder. In particular, this work focuses on the influence of the binder content on the porosity and pore interconnectivity in Si composite electrode (Si + C):CMC materials. Our data from HP 129Xe NMR spectra show that the CMC content has an effect on the porosity and pore interconnectivity of Si nanocomposite electrode materials. We determined parameters, such as pore size, heat of adsorption, and characteristic chemical shift, of (Si + C):CMC samples based on the temperature-dependent HP 129Xe...

나노 TiO<sub>2</sub>를 적용한 식품 포장 필름 개발 및 콩나물의 이취 제거

For testing the ultraviolet (UV)-blocking property of functional films coated with Nano-TiO₂ particles, UV-Vis spectra of oriented polypropylene (OPP) films uncoated and coated with TiO₂ of 3% and 5% in Polyurethane (PU) and polyvinyl butyral (PVB)-Cellulose binders were measured. The result of UV-Vis analyses showed that the film coated with 5% TiO₂ in PVB binders had a significant effect on UV protection of 90% compared with the film uncoated. Also The result of The photodegradation of methylene blue (MB), OPP films coated with 5% in both PU and PVB binders had a high photocatalytic activity for MB degradation. To evaluate the effect of the developed functional film coated with Nano-TiO₂ particles, fresh soybean sprouts were used. Nano-TiO₂ coated film was observed to decompose the off-flavor produced by soybean sprouts within packages during distribution, but uncoated film did not. Therefore, Nano-TiO₂ coated film package could give the greatest effect in extending the shelf life of soybean sprouts.

Ionically‐Functionalized Poly(thiophene) Conductive Polymers as Binders for Silicon and Graphite Anodes for Li‐Ion Batteries

AbstractNext‐generation anode materials for Li‐ion batteries such as silicon can lead to ten times more capacity than the state‐of‐the‐art graphite. However, novel binders are required to overcome the detrimental effects of volume changes during battery cycling of silicon because of the poor chemical interaction and electrical conductivity between silicon and the binder. Most studies focus on either ionic binders or electrically conductive binders, but herein it was demonstrated that a new family of polymers based on electrically conductive poly(thiophene) functionalized with an ionic alkyl carboxylate groups of various lengths can successfully work as multifunctional binders for silicon and commercial graphite anodes in Li‐ion battery half‐cells. It was determined that the polymer with shorter side chain (PT‐3‐LiA) gives the highest reversible capacity upon pairing with graphite or silicon, reaching 3000 mAh g−1 in the case of the latter, a capacity 500 mAh g−1 (≈22 %) higher than those obtained with the electrically, but non‐ionically, conductive PEDOT:PSS binder and the ionically, but non‐electrically, conductive sodium carboxymethyl cellulose (NaCMC) binder. It is demonstrated that the superior performance of this new type of multifunctional binders can be attributed to their ability to maintain their doping level and conductivity as well as due to good interaction with the silicon surface during cycling.

Cyanoethylated Carboxymethyl Chitosan as Water Soluble Binder with Enhanced Adhesion Capability and electrochemical performances for LiFePO4 Cathode

Cyanoethylated carboxymethyl chitosan (CN-CCTS) has been synthesized through a straightforward cyanoethylation reaction by reacting CCTS with acrylonitrile in NaOH aqueous solution. CN-CCTS shows improved adhesion strength of 0.047N/cm as compared with 0.013N/cm for CCTS after introducing cyanoethyl group in the chemical structure of CCTS. The electrochemical performances of LiFePO4 electrode with CN-CCTS binder have been investigated and compared with those using water soluble sodium carboxymethyl cellulose (CMC) and non-aqueous polyvinylidene difluoride (PVDF) binder. LiFePO4 electrode with CN-CCTS exhibits better cycling stability and rate capability, retaining 56.3% capacity of C/5 at 5C rate as compared with 48.4% and 32.8% for CMC and PVDF, respectively. Cyclic voltammetry and electrochemical impedance spectroscopy measurement reveal that LiFePO4 electrode with CN-CCTS has a more favorable electrochemical kinetics than that with CMC and PVDF, thus better rate capability.

Special tablets containing cellulose binder and Sr internal standard for simplifying X-ray fluorescence analysis of powder samples

The addition of a constant amount of SrCO3 was observed to be the proper internal standard for analysis by wavelength-dispersive X-ray fluorescence spectrometry to correct the matrix and grain size effects of many constituents. The weighing of constant amounts of SrCO3, binder and sample allowed for the preparation time for analysis to be extended, and special tablets containing binder and SrCO3 were developed. Several substances were tested as binders, among which microcrystalline cellulose was chosen for further study. The prepared tablets were checked for their weight stability and the repeatability of SrCO3 addition. The tablets were then used to prepare pellets from geological samples for X-ray fluorescence analysis. The exemplary application and calibration curves for several analytes confirmed that the prepared tablets could be useful for the pelletizing of such materials to compensate for matrix effects.

Effect of Crosslinking of Guar Gum As a Bio-Derivative Binder for Negative Electrodes of Lithium-Ion Batteries

Nowadays, large-sized lithium-ion batteries (LIB) for electric vehicles (EV) and energy storage systems (ESS) require extraordinary long-cycled, high-powered, and high-capacity, when compared to small-sized LIBs for mobile devices. In addition, it is also necessary to actively respond to environmental problems by applying green materials. From our previous results, guar gum binders, branched polysaccharides, facilitated the transport of lithium ions in Li4Ti5O12(LTO) electrodes than conventional carboxymethyl cellulose (CMC) binders, linear polysaccharide, even though their adhesive strength were not as strong as CMC[1]. Unlike polyvinylidene fluoride (PVdF), guar gum binder was soluble in water, thus allowing the LIB manufacturing process to be environmentally friendly. In this study, we investigate the effect of crosslinking of the guar gum binder on their mechanical properties in the LTO electrodes. To evaluate the effect of these crosslinking, a variety of physical and electrochemical characterization are applied. Reference 1. Bo-Ram Lee, So-Jin Kim and Eun-Suok Oh, Journal of the Electrochemical Society, 161, A2128-A2132 (2014)

Effects of polymer binder on rheological properties of silver pastes for screen printing front electrode films of solar cells

The purpose of the study is to characterize and improve the fundamental understanding of the effects of Ethyl Cellulose (EC) binder on the rheological properties of silver pastes for screen printing front electrode films of solar cells. Dispersions of silver particles (surface modified with oleic acid) in EC polymer solutions with and without thixotropic agent were prepared; and yield stress values were measured by setting shear stress to characterize the strength of interaction in pastes. Week flocculation network of silver particles is produced due to depletion of flocculation. EC polymer also has a significant interaction with thixotropic agent. Down-sweep flow curves of dispersions without thixotropic agent were measured and well fitted by Generalized Casson model. The model parameters p indicated that EC polymer with high molecular weight has a stronger shear-thinning ability. Steady-state flow, three interval thixotropy shear test (3ITT) and oscillatory measurements were conducted to study the effect of EC content on viscosity, structure rebuilding and viscoelastic properties of electrode pastes. Increasing EC polymer is not the best way to prevent the layer printed from laying down.

Processing of Alumina Honeycomb Catalyst Substrates and Studies on Methyl Cellulose Binder Burn Out Kinetics

Processing of Alumina Honeycomb Catalyst Substrates and Studies on Methyl Cellulose Binder Burn Out Kinetics

Cathodically induced antimony for rechargeable Li-ion and Na-ion batteries: The influences of hexagonal and amorphous phase

Cathodic corrosion, a green electrochemical method, has been employed to obtain Sb nanomaterials utilized as anode material for lithium-ion batteries and sodium-ion batteries. Interestingly, two different corrosion mechanisms are found, coming from the impact of electrolyte, resulting in the formation of hexagonal and amorphous Sb in aqueous and organic solution, respectively. With the help of water-soluble carboxymethyl cellulose binder and the electrolyte additive fluoroethylene carbonate, both hexagonal and amorphous Sb electrodes exhibit good cycling stability when utilized as anode materials for lithium-ion batteries and sodium-ion batteries. Additionally, both the hexagonal and amorphous Sb electrodes show very good rate capability in lithium-ion batteries. Even at high current density (2000 mA g−1), the hexagonal and amorphous Sb give reversible capacities of 422 and 379 mA h g−1, respectively. Surprisingly, when used as anode materials for sodium-ion batteries, the hexagonal Sb electrode exhibits a good rate performance of 632, 625, 569, 515 and 426 mA h g−1 at a current density of 100, 200, 500, 1000, and 2000 mA g−1, respectively. However, limited rate performance is observed from the amorphous Sb electrode in case of sodium-ion battery due to the large impedance.