Cellulose-based material in lithium-sulfur batteries: A review

Cationic cellulose nanofiber solid electrolytes: A pathway to high lithium-ion migration and polysulfide adsorption for lithium-sulfur batteries

Polyethylene oxide (PEO) solid electrolytes, acknowledged for their safety advantages over liquid counterparts, confront inherent challenges, including low ionic conductivity, restricted lithium ion migration, and mechanical fragility, notably pronounced in lithium‑sulfur batteries due to the polysulfide shuttling phenomenon. To address these limitations, we integrate a quaternary ammonium cation-modified cellulose (QACC) nanofiber, electrospun with cellulose acetate (CA) from recycled cigarette filters, into the PEO electrolyte matrix. The nitrogen atom within the quaternary ammonium group exhibits a pronounced affinity for polysulfide compounds, effectively curtailing polysulfide migration. Concurrently, Lewis acid-base interactions between quaternary ammonium groups and lithium salt anions facilitate the release of additional Li+, achieving a lithium-ion transference number 1.5 times higher than its pure PEO counterpart. Furthermore, the introduction of a larger trifluoromethanesulfonimide (TFSI) group on the QACC macromolecule (TFSI-QACC) disrupts the ordered arrangement of PEO macromolecules, resulting in a noteworthy enhancement in ionic conductivity, reaching 2.07 × 10-4 S cm-1 at 60 °C, thus addressing the challenge of low PEO electrolyte conductivity. Moreover, the nanofiber enhances the mechanical strength of the PEO electrolyte from 0.49 to 7.50 MPa, mitigating safety concerns related to lithium dendrites puncturing the electrolyte. Consequently, the composite PEO demonstrates exemplary performance in lithium symmetrical batteries, enduring 500 h of continuous operation and completing 100 cycles at both room and elevated temperatures. This integrated approach, transitioning from waste to wealth, adeptly addresses a spectrum of challenges in the efficiency of solid-state electrolytes, holding considerable promise for advancing lithium‑sulfur battery technology.

Insights into the aspect ratio effects of ordered mesoporous carbon on the electrochemical performance of sulfur cathode in lithium-sulfur batteries

Tailoring porous host materials, as an effective strategy for storing sulfur and restraining the shuttling of soluble polysulfides in electrolyte, is crucial in the design of high-performance lithium-sulfur (Li-S) batteries. However, for the widely studied conductive hosts such as mesoporous carbon, how the aspect ratio affects the confining ability to polysulfides, ion diffusion as well as the performances of Li-S batteries has been rarely studied. Herein, ordered mesoporous carbon (OMC) is chosen as a proof-of-concept prototype of sulfur host, and its aspect ratio is tuned from over ∼ 2 down to below ∼ 1.2 by using ordered mesoporous silica hard templates with variable length/width scales. The correlation between the aspect ratio of OMCs and the electrochemical performances of the corresponding sulfur-carbon cathodes are systematically studied with combined electrochemical measurements and microscopic characterizations. Moreover, the evolution of sulfur species in OMCs at different discharge states is scrutinized by small-angle X-ray scattering. This study gives insight into the aspect ratio effects of mesoporous host on battery performances of sulfur cathodes, providing guidelines for designing porous host materials for high-energy sulfur cathodes.

A Light-Thin Chitosan Nanofiber Separator for High-Performance Lithium-Ion Batteries

With the development of portable devices and wearable devices, there is a higher demand for high-energy density and light lithium-ion batteries (LIBs). The separator is a significant component directly affecting the performance of LIBs. In this paper, a thin and porous chitosan nanofiber separator was successfully fabricated using the simple ethanol displacement method. The thickness of the CME15 separator was about half that of mainstream commercial Celgard2325 separators. Owing to its inherent polarity and high porosity, the obtained CME15 separator achieved a small contact angle (18°) and excellent electrolyte wettability (324% uptake). The CME15 separator could maintain excellent thermal dimensional stability at 160 °C. Furthermore, the CME15 separator-based LIBs exhibited excellent cycling performance after 100 cycles (117 mAh g-1 at 1 C). The present work offers a perspective on applying a chitosan nanofiber separator in light and high-performance lithium-ion batteries (LIBs).

Polyolefin-Based Separator with Interfacial Chemistry Regulation for Robust Potassium Metal Batteries

Potassium metal batteries (KMBs) are ideal choices for high energy density storage system owing to the low electrochemical potential and low cost of K. However, the practical KMB applications suffer from intrinsically active K anode, which would bring serious safety concerns due to easier generation of dendrites. Herein, to explore a facile approach to tackle this issue, we propose to regulate K plating/stripping via interfacial chemistry engineering of commercial polyolefin-based separator using multiple functional units integrated in tailored metal organic framework. As a case study, the functional units of MIL-101(Cr) offer high elastic modulus, facilitate the dissociation of potassium salt, improve the K+ transfer number and homogenize the K+ flux at the electrode/electrolyte interface. Benefiting from these favorable features, uniform and stable K plating/stripping is realized with the regulated separator. Full battery assembled with the regulated separator showed ∼19.9 % higher discharge capacity than that with glass fiber separator at 20 mA g-1 and much better cycling stability at high rates. The generality of our approach is validated with KMBs using different cathodes and electrolytes. We envision that the strategy to suppress dendrite formation by commercial separator surface engineering using tailor-designed functional units can be extended to other metal/metal ion batteries.

Noble-metal-free co-N-C catalyst derived from cellulose-based poly(ionic liquid)s for highly efficient oxygen reduction reaction

Noble-Metal-Free nitrogen-doped carbon-based materials are promising electrocatalysts for oxygen reduction reaction (ORR), yet it remains a great challenge to construct efficient porous non-noble metal nitrogen-doped carbon (M-N-C) catalysts with uniform distribution, due to the easy aggregation of metals. Herein, we reported the synthesis and assessment of a novel and efficient noble-metal-free catalyst for oxygen reduction reaction (ORR) from pyrolysis of a cobalt-containing cellulosic poly(ionic liquid) (Co-N-C). The prepared Co-N-C catalyst possesses high surface area, hierarchical porous structure, well-dispersed Co nanoparticles and large amounts of low-coordinated Co active sites. Especially, the Co-N-C-850 sample exhibits a high ORR activity (E_onset = 0.827 V, E_1/2 = 0.74 V) that can rival 20 wt% commercial Pt/C (E_onset = 0.833 V, E_1/2 = 0.71 V) in alkaline media. Moreover, the Co-N-C-850 sample also shows excellent anti-methanol poisoning activity and long-term stability toward ORR compared with commercial Pt/C. Our study provides a promising avenue both for the development of non-noble M-N-C catalysts for fuel cells and functional utilization of cellulose.

Advances in Cellulose-Based Composites for Energy Applications

The various forms of cellulose-based materials possess high mechanical and thermal stabilities, as well as three-dimensional open network structures with high aspect ratios capable of incorporating other materials to produce composites for a wide range of applications. Being the most prevalent natural biopolymer on the Earth, cellulose has been used as a renewable replacement for many plastic and metal substrates, in order to diminish pollutant residues in the environment. As a result, the design and development of green technological applications of cellulose and its derivatives has become a key principle of ecological sustainability. Recently, cellulose-based mesoporous structures, flexible thin films, fibers, and three-dimensional networks have been developed for use as substrates in which conductive materials can be loaded for a wide range of energy conversion and energy conservation applications. The present article provides an overview of the recent advancements in the preparation of cellulose-based composites synthesized by combining metal/semiconductor nanoparticles, organic polymers, and metal-organic frameworks with cellulose. To begin, a brief review of cellulosic materials is given, with emphasis on their properties and processing methods. Further sections focus on the integration of cellulose-based flexible substrates or three-dimensional structures into energy conversion devices, such as photovoltaic solar cells, triboelectric generators, piezoelectric generators, thermoelectric generators, as well as sensors. The review also highlights the uses of cellulose-based composites in the separators, electrolytes, binders, and electrodes of energy conservation devices such as lithium-ion batteries. Moreover, the use of cellulose-based electrodes in water splitting for hydrogen generation is discussed. In the final section, we propose the underlying challenges and outlook for the field of cellulose-based composite materials.

Recent Development in Novel Lithium-Sulfur Nanofiber Separators: A Review of the Latest Fabrication and Performance Optimizations

Lithium-Sulfur batteries (LSBs) are one of the most promising next-generation batteries to replace Li-ion batteries that power everything from small portable devices to large electric vehicles. LSBs boast a nearly five times higher theoretical capacity than Li-ion batteries due to sulfur's high theoretical capacity, and LSBs use abundant sulfur instead of rare metals as their cathodes. In order to make LSBs commercially viable, an LSB's separator must permit fast Li-ion diffusion while suppressing the migration of soluble lithium polysulfides (LiPSs). Polyolefin separators (commonly used in Li-ion batteries) fail to block LiPSs, have low thermal stability, poor mechanical strength, and weak electrolyte affinity. Novel nanofiber (NF) separators address the aforementioned shortcomings of polyolefin separators with intrinsically superior properties. Moreover, NF separators can easily be produced in large volumes, fine-tuned via facile electrospinning techniques, and modified with various additives. This review discusses the design principles and performance of LSBs with exemplary NF separators. The benefits of using various polymers and the effects of different polymer modifications are analyzed. We also discuss the conversion of polymer NFs into carbon NFs (CNFs) and their effects on rate capability and thermal stability. Finally, common and promising modifiers for NF separators, including carbon, metal oxide, and metal-organic framework (MOF), are examined. We highlight the underlying properties of the composite NF separators that enhance the capacity, cyclability, and resilience of LSBs.

Cellulose: Characteristics and applications for rechargeable batteries

Cellulose, an abundant natural polymer, has promising potential to be used for energy storage systems because of its excellent mechanical, structural, and physical characteristics. This review discusses the structural features of cellulose and describes its potential application as an electrode, separator, and binder, in various types of high-performing batteries. Various surface and structural characteristics of cellulose (e.g., fiber size, surface functional groups, the hierarchy of pores, and porosity levels) that contribute to its electrochemical performance are discussed. Cellulose structure/property/processing/function relationships are further focused and elucidated in terms of the latest developments in the emerging field of sustainable materials in Li-Ion, Na-Ion, and LiS batteries.

Synergistic Capture and Conversion of Soluble Polysulfides in Li-S Batteries with Composite Freestanding Carbonaceous Interlayers

Lithium-sulfur (Li-S) batteries are considered promising next-generation energy storage systems due to their high energy density and low cost. However, their practical application still faces challenges such as the "shuttle effect" caused by polysulfides (LiPS). In this work, we use environmentally friendly bacterial cellulose (BC) as the substrate and prepare a flexible Ni-containing coordination polymer-modified carbonized BC interlayer (Ni-CBC). The combined electrochemical theoretical analysis shows that Ni-CBC not only captures LiPS effectively but also facilitates the electrochemical conversion of the adsorbed LiPS. As a result of these favorable features, the battery with the Ni-CBC interlayer delivers a stable discharge performance at 0.2C during long charge-discharge cycles and a high rate capacity of 852 mAh g^-1 at 2C. This work suggests that cellulose-based materials with tailored functionality can improve the performance of Li-S batteries.

Lignin-Based Materials for Sustainable Rechargeable Batteries

This review discusses important scientific progress, problems, and prospects of lignin-based materials in the field of rechargeable batteries. Lignin, a component of the secondary cell wall, is considered a promising source of biomass. Compared to cellulose, which is the most extensively studied biomass material, lignin has a competitive price and a variety of functional groups leading to broad utilization such as adhesive, emulsifier, pesticides, polymer composite, carbon precursor, etc. The lignin-based materials can also be applied to various components in rechargeable batteries such as the binder, separator, electrolyte, anode, and cathode. This review describes how lignin-based materials are adopted in these five components with specific examples and explains why lignin is attractive in each case. The electrochemical behaviors including charge–discharge profiles, cyclability, and rate performance are discussed between lignin-based materials and materials without lignin. Finally, current limitations and future prospects are categorized to provide design guidelines for advanced lignin-based materials.

Flexible, Electrically Conductive, Nanostructured, Asymmetric Aerogel Films for Lithium-Sulfur Batteries

Lithium-sulfur batteries are afflicted with capacity fading on account of polysulfide shuttling. A novel cost-effective electrode that can hinder the polysulfide shuttling and realize high active material utilization is highly required. Here, we demonstrate a flexible, electrically conductive, nanostructured, and asymmetric hybrid cathode by integrating a high-aspect-ratio wood nanocellulose and a low-cost commercial carbon nanotube (∼$ 0.2 g^-1) into an entangled aerogel film. The vacuum filtration combined with lyophilization enables the aerogel film with quite different nanofiber/nanotube packing densities and pore structures at its two sides. The cooperative effects of the entangled building blocks and the asymmetric porous structure of the aerogel film stimulate the simultaneous increase of active sulfur loading, enhancing the electrolyte penetration, alleviating dissolution and shuttling of polysulfide ions, and promoting the fast electron transportation. The as-generated cathode exhibited a capacity fading of 0.01% per cycle over 1000 discharge/charge cycles at a 0.5 C rate (1 C = 1675 mA g^-1). The average Coulombic efficiency reached ∼99.7%.

Fluorinated Graphite (FG)-Modified Li-S Batteries with Superhigh Primary Specific Capacity and Improved Cycle Stability

Lithium-sulfur (Li-S) batteries have received extensive attention because of their high theoretical energy density and low cost. However, the low sulfur utilization and the shuttle effect of polysulfide cause low initial capacity and serious capacity decay. Herein, fluorinated graphite (FG) is introduced to the cathode to alleviate these issues. The results indicated that the FG could provide additional capacity during the first discharge process and increase the porosity and polarity of the cathode via in situ formation of lithium fluoride (LiF) nanocrystals, which can enhance the infiltration of electrolyte and polysulfide adsorption. As a result, the as-prepared cathode containing FG shows a high initial specific capacity of 1602 mA h g-1 and the reversible specific capacity is 650 mA h g-1 at 0.5C after 300 cycles. Moreover, its specific capacity remains at 860 mA h g-1 at 5C, which is 367% higher than that of the sample without FG. This paper provides a new strategy to improve the energy density and the cycle stability of Li-S batteries.

Seaweed-based cellulose: Applications, and future perspectives

Cellulose is a naturally occurring organic polymer extracted mainly from lignocellulosic biomass of terrestrial origin. However, the increasing production of seaweeds for growing global market demands has developed the opportunity to use it as an additional cellulose source. This review aims to prepare comprehensive information to understand seaweed cellulose and its possible applications better. This is the first review that summarizes and discusses the cellulose from all three types (green, red, and brown) of seaweeds in various aspects such as contents, extraction strategies, and cellulose-based products. The seaweed cellulose applications and future perspectives are also discussed. Several seaweed species were found to have significant cellulose content (9-34% dry weight). The review highlights that the properties of seaweed cellulose-based products were comparable to products prepared from plant-based cellulose. Overall, this work demonstrates that cellulose could be economically extracted from phycocolloids industrial waste and selected cellulose-rich seaweed species for various commercial applications.

Review on Comparison of Different Energy Storage Technologies Used in Micro-Energy Harvesting, WSNs, Low-Cost Microelectronic Devices: Challenges and Recommendations

This paper reviews energy storage systems, in general, and for specific applications in low-cost micro-energy harvesting (MEH) systems, low-cost microelectronic devices, and wireless sensor networks (WSNs). With the development of electronic gadgets, low-cost microelectronic devices and WSNs, the need for an efficient, light and reliable energy storage device is increased. The current energy storage systems (ESS) have the disadvantages of self-discharging, energy density, life cycles, and cost. The ambient energy resources are the best option as an energy source, but the main challenge in harvesting energy from ambient sources is the instability of the source of energy. Due to the explosion of lithium batteries in many cases, and the pros associated with them, the design of an efficient device, which is more reliable and efficient than conventional batteries, is important. This review paper focused on the issues of the reliability and performance of electrical ESS, and, especially, discussed the technical challenges and suggested solutions for ESS (batteries, supercapacitors, and for a hybrid combination of supercapacitors and batteries) in detail. Nowadays, the main market of batteries is WSNs, but in the last decade, the world's attention has turned toward supercapacitors as a good alternative of batteries. The main advantages of supercapacitors are their light weight, volume, greater life cycle, turbo charging/discharging, high energy density and power density, low cost, easy maintenance, and no pollution. This study reviews supercapacitors as a better alternative of batteries in low-cost electronic devices, WSNs, and MEH systems.

Polysaccharides for sustainable energy storage - A review

The increasing amount of electric vehicles on our streets as well as the need to store surplus energy from renewable sources such as wind, solar and tidal parks, has brought small and large scale batteries into the focus of academic and industrial research. While there has been huge progress in performance and cost reduction in the past years, batteries and their components still face several environmental issues including safety, toxicity, recycling and sustainability. In this review, we address these challenges by showcasing the potential of polysaccharide-based compounds and materials used in batteries. This particularly involves their use as electrode binders, separators and gel/solid polymer electrolytes. The review contains a historical section on the different battery technologies, considerations about safety on batteries and requirements of polysaccharide components to be used in different types of battery technologies. The last sections cover opportunities for polysaccharides as well as obstacles that prevent their wider use in battery industry.

Photocatalytic Behaviour of Zinc Oxide Nanostructures on Surface Activation of Polymeric Fibres

Zinc oxide (ZnO) in various nano forms (nanoparticles, nanorods, nanosheets, nanowires and nanoflowers) has received remarkable attention worldwide for its functional diversity in different fields i.e., paints, cosmetics, coatings, rubber and composites. The purpose of this article is to investigate the role of photocatalytic activity (role of photogenerated radical scavengers) of nano ZnO (nZnO) for the surface activation of polymeric natural fibres especially cotton and their combined effect in photocatalytic applications. Photocatalytic behaviour is a crucial property that enables nZnO as a potential and competitive candidate for commercial applications. The confirmed features of nZnO were characterised by different analytical tools, i.e., scanning electron microscopy (SEM), field emission SEM (FESEM) and elemental detection spectroscopy (EDX). These techniques confirm the size, morphology, structure, crystallinity, shape and dimensions of nZnO. The morphology and size play a crucial role in surface activation of polymeric fibres. In addition, synthesis methods, variables and some of the critical aspects of nZnO that significantly affect the photocatalytic activity are also discussed in detail. This paper delineates a vivid picture to new comers about the significance of nZnO in photocatalytic applications.