With the increasing global demand for net-zero carbon emissions, actions to address climate change have gained momentum among policymakers and the public. The urgent need for a sustainable economy is underscored by the mounting waste crisis in landfills and oceans. However, the proliferation of distributed electronic devices poses a significant challenge due to the resulting electronic waste. To combat this issue, the development of sustainable and environmentally friendly materials for these devices is imperative. Cellulose, an abundant and CO2-neutral substance with a long history of diverse applications, holds great potential. By integrating electrically interactive components with cellulosic materials, innovative biobased composites have been created, enabling the fabrication of bulk electroactive paper and the establishment of new, potentially more sustainable manufacturing processes for electronic devices. This review explores recent advances in bulk electroactive paper, including the fundamental interactions between its constituents, manufacturing techniques, and large-scale applications in the field of electronics. Furthermore, it addresses the importance and challenges of scaling up production of electroactive paper, highlighting the need for further research and development.

Lignin has been extensively researched as a cathode active material in secondary batteries. In the present work, the energy storage potential of lignin naturally present in papers made of chemi-thermomechanical pulp (CTMP) is explored. More specifically, effects from CTMP fines on the electrochemical characteristics have been studied. Compared to pulp fibers, fines are higher in lignin content and have higher specific surface area. It was expected that this would be positive for the electrode performance; however, the result points to the opposite. The fines do not significantly contribute to a higher lignin specific capacity, and they deteriorate the cycling stability. Higher fines content was found to result in a higher oxidative activity as well as more abundant competing reactions. These competing reactions are believed to be linked to the cycle stability. Therefore, we hypothesize that the electrochemical stability of lignin can be better understood by studying differences between fines and fiber lignin. As the theoretical specific capacity of this material is about 20 times larger than obtained here, identification of the reasons for this capacity discrepancy is needed to realize the full potential of lignin-based paper batteries.

Taking ideas to market can be a long, iterative, and complex process. When dealing with new bio-based materials, under-standing factors that help bridge the lab-to-market gap and how materials are selected for new product development have the potential to speed up the transition to a circular bioeconomy. This article defines abstract and conceptual material demonstrators and explores how they support the innovation process in different ways. Nine roles are iden-tified, including how material demonstrators contribute to generating and expressing new ideas, enable a shared understanding of technology, support the discovery of market value and the visualization of potential applications as well as helping to articulate internal and external strategies and communications. Abstract and conceptual material dem-onstrators are exemplified with both technology-driven and market-driven bio-based materials used in packaging.

Due to growing concerns about the environmental impacts of fossil fuels and the capacity and resilience of energy grids around the world, engineers and policymakers are increasingly turning their attention to energy storage solutions1. In turn, the huge demand for materials for such storage systems will require a considerable energy input in extraction, processing and materials formulation, and new and sustainable electrochemical systems need to be developed2. Current report is the result of the exploration work where the circularity and environmental potentials of biobased energy storage solutions were analysed in the form of iterative interviews with stakeholders along the energy storage and packaging value chains, complemented by literature research. The work was performed within the scope of Digital Cellulose Center (DCC) research center3 in the sub-project 1 “Circularity of DCC materials” of the Theme 1: Design for a circular bioeconomy. Totally three systems were selected and analysed in the form of three respective case studies: • Case study I: Biobased battery (Chemical energy storage system) • Case study II: Biobased printed supercapacitor (Electrochemical energy storage system) • Case study III: Intelligent packaging (Chemical or electrochemical energy storage for fiber-based packaging) Each case study was put into the life cycle context where aspects such as legislation, circularity potential and potential environmental impact were discovered. The biobased battery for large-scale grid storage applications was classified as an industrial battery with collection rate requirement of 75% at end-of-life, of which 50% to be materially recycled. The biobased printed supercapacitor was classified as an electric and electronic equipment (EEE) with collection rate requirement of 65%, of which recovery and recycling / preparing for reuse targets vary between 55% - 85% depending on application. The material recycling target for the fiber-based intelligent packaging is 85% since being perceived as a paper-based packaging it would enter paper packaging recycling stream rather than entering the recycling stream of Waste electrical and electronic equipment (WEEE). In next steps of this exploratory journey, the compositions of the respective energy storage solutions were identified, including biobased content and recycling potential on the short- and long-term, compared to their benchmark solutions where possible. Today, the material recycling processes for batteries and WEEE are strongly economically driven: the material components that are considered as valuable by recyclers are mainly base metals (e.g., aluminium, steel) and to low extent critical raw materials (e.g., cobalt, nickel). The biobased energy storage solutions though do not contain any critical raw materials and use base metals to a less extent. This is a dilemma where the material value of the biobased, renewable materials (more sustainable materials by origin) is not favourable in the end-of-life processes of today and therefore will be lost (i.e., incinerated). A more balanced approach to such dilemma is urged in order to facilitate both economic and environmental incentives in the energy storage value cycles. Current Battery and WEEE directives do not promote the recycling of materials that are critical or have a high environmental burden, which in practice results in loss of those materials, not least due to lack of economy in recycling processes. Moreover, the legislation needs to be adapted in order to meet innovative development in the area. It can be relevant to introduce a cross-sectoral category ‘Biobased energy storage solutions’ in the upcoming legislation with the aim to encourage use of more abundant, biobased materials and thus decouple energy storage applications from use of critical raw materials.

The society is transitioning towards a circular economy and the Digital Cellulose Center (DCC) that develops green electronics may play an important role in it. The research within the DCC focuses on the topic of digital cellulose, where cellulose is combined with electroactive material, making it possible to develop electrically active cellulose products that can communicate with the digital world while remaining sustainable. This could mean entirely new types of active packaging solutions, able to sense and adapt to their surroundings, or paper rolls able to store energy from solar cells or wind power [1]. This document offers guidance for the DCC stakeholders on the choice of sustainable materials for green electronics, focusing on the two life cycle phases of a product: • Raw materials • End-of-life Since the DCC green electronics are still in the development stage, a future scenario analysis has been applied in order to envision the possible future outcomes. The DCC green electronics have been explored in two opposite future scenarios: • Stuck in the Mud – A business-as-usual scenario, where the year 2045 is more or less the same as year 2022. • Circular Dawn – Where the circular economy has become a new normal and the whole society is thriving in a resource-efficient, circular and biobased economy. The guideline contains a sustainability checklist adapted to the needs of the DCC stakeholders for more informed decision-making and for being able to drive the development towards a circular economy, i. e. the future scenario Circular Dawn.

The global efforts in electrifying our society drive the demand for low-cost and sustainable energy storage solutions. In the present work, a novel material concept was investigated to enable fabrication of several 10 meter-long rolls of supercapacitor paper electrodes on a pilot-scale paper machine. The material concept was based on cationized, cellulose-rich wood-derived fibres, conducting polymer PEDOT:PSS, and activated carbon filler particles. Cationic fibres saturated with anionic PEDOT:PSS provide a conducting scaffold hosting the activated carbon, which functions as the active charge-storage material. The response from further additives was systematically investigated for several critical paper properties. Cellulose nanofibrils were found to improve mechanical properties, while carbon black enhanced both the conductivity and the storage capacity of the activated carbon, reaching a specific capacitance of 67 F g−1. This pilot trial shows that “classical” papermaking methods are fit for the purpose and provides valuable insights on how to further advance bio-based energy storage solutions for large-scale applications.

An environmentally benign synthesis of a magnetically responsive carboxymethylated cellulose nanofibril-based material is reported. Applied experimental conditions lead to the in-situ formation of magnetite nanoparticles with primary particle sizes of 2.0–4.0 nm or secondary particles of 3.6–16.4 nm depending on whether nucleation occurred between individual carboxymethylated cellulose nanofibrils, or on exposed fibril surfaces. The increase in magnetite particle size on the cellulose fibril surfaces was attributed to Ostwald ripening, while the small particles formed within the carboxymethyl cellulose aggregates were presumably due to steric interactions. The magnetite nanoparticles were capable of coordinating to carboxymethylated cellulose nanofibrils to form large “fibre-like” assemblies. The confinement of small particles within aggregates of reductive cellulose molecules was most likely responsible for excellent conservation of magnetic characteristics on storage of this material. The possibility for using the material in drug delivery applications with release rate controlled by daylight illumination is presented. © 2022 The Author(s)

Research in smart textiles is growing due to the increased demand from the healthcare sector and people's urge to keep track of and analyze the signals and metrics from their bodies. Electrically conductive filaments are the most fundamental material for smart textiles. These filaments can be imbued with functionalities and useful in fields like energy storage, sensing, and actuation. To be able to meet the requirements that the latter applications require, fabrication techniques must be developed to provide better processability and sustainability in a cost-effective manner. Here, a mixture of a conductive polymer, poly(3,4-ethylenedioxythiophene) (PEDOT), and biobased cellulose nanofibrils (CNFs) was used to spin filaments utilizing a water-based process. These filaments show electrical conductivities up to 150 S/cm and tensile stiffness of 20 GPa. Interestingly, the PEDOT aligned to a similar degree as the CNFs during the spinning process without a drawing step, which is hypothesized to be caused by the attachment of PEDOT on the CNFs. Lastly, the filaments were tested in an organic electrochemical transistor (OECT) configuration, which resulted in a working device with an on/off ratio approaching 1500. Furthermore, the OECT exhibited stable behavior when changing temperature (20-80 °C) and relative humidity (40-80%). This aqueous spinning method, resulting in filaments with robust electronic properties in different temperature and humidity environments, show greats promise for future innovative smart textiles.

Graphite materials show high electrical and thermal conductivity making them useful in electronics both as electrical conductor, but as of today primarily used as a thermal conductor for thermal management and as the dominating anode material in lithium ion batteries. The conductivities depend on for example the degree of graphitisation, that is how close the material is to perfect graphite. Graphite materials can occur naturally in the earth’s bedrock and can thus be extracted by mining and is then called natural graphite. Graphitic carbon materials can also be synthesised and are then usually referred to a synthetic or artificial graphite, even though they should be referred to as graphite materials if being strict, as they never reach the structure of perfect graphite and always contain some defects and irregularities. This report starts with a short description of all carbon allotropes, i.e. structurally different forms of the same element due to how the atoms are chemically bonded to each other. It then continues with an overview of how graphitic carbon materials can and should be characterised, as well as analytical methods for making this characterisation. After this a section on production methods for graphite materials follows, that dependent on the principles they operate by are divided into: • Mining for graphite that occurs naturally in the earth’s bedrock. • High temperature heat-treatment, so called carbonisation, hydrothermal carbonisation if done in water, and graphitisation. • Chemical vapour deposition, i.e. depositing molecules or atoms in gas phase on a solid surface, that is used to synthesise pyrolytic carbon and graphite. • Extraction from a steelmaking by-product called Kish to obtain so called Kish graphite. • Thermal decomposition of carbides. This is followed by a section on the today most common and important graphite materials, which are: natural graphite (mined), anisotropic synthetic graphite, isotropic synthetic graphite, pyrolytic carbon and graphite. This section also includes specific production process details for the above listed graphite materials, their main properties, advantages, and common uses. Two of the most common and important uses of graphite materials, i.e. as anode in lithium ion batteries and for thermal management in electronics, are described somewhat more in depth. The focus of this report is biomass derived graphitic materials and this focus start fully first in section number four, which compares published values on electrical and thermal conductivity of different fossil and bio-based graphitic carbon materials. This comparison clearly shows that it is very challenging to derive graphitic carbon materials with high conductivities from biomass. This is because essentially all biomass is so-called non-graphitising or hard carbon precursor meaning that it is not transformed into highly graphitic carbon no matter how high temperature it is heated to. Catalytic graphitisation using metals salts or oxides can increase the degree of graphitisation that can be achieved, but all substances used for catalysing graphitisation forms solid nanoparticles which leaves voids when removed by for example acid dissolution, making the resulting graphitic material porous which in turn limits its electrical and thermal conductivity. Of all production processes reviewed here to create highly electrically and thermally conductive graphitic carbon materials from biomass, requiring a high degree of graphitisation and dense material, two methods stand out as especially interesting: • Chemical vapour deposition on suitable substrate (carbon materials, metals or ceramics) using biomass as carbon source. • Resistive heating of biomass derived films/objects. Bio-based free-standing graphene film with very high electrical and thermal conductivity have been produced using chemical vapour deposition technique. From a practical handling perspective, it would be beneficial to create thicker highly graphitic carbon films to make them stronger, although it may reduce the conductivities of the material. Methods based on chemical vapour deposition may be improved to be able to produce thicker graphitic films. Resistive heating of a film made of e.g. biobased lignin, mixed with mined graphene to 2192 °C have been shown to create a highly graphitic carbon film with the excellent electrical conductivity of 4480 S/cm. By substituting the mined graphene to bio-based ditto may open up for the production of a fully biobased, highly graphitic film with excellent conductive properties. It is suggested that the way to achieve fully biobased highly graphitic and dense films is to further refine the chemical vapour deposition and the resistive heating method.

This study presents a novel, green, and efficient way of preparing crosslinked aerogels from cellulose nanofibers (CNFs) and alginate using non-covalent chemistry. This new process can ultimately facilitate the fast, continuous, and large-scale production of porous, light-weight materials as it does not require freeze-drying, supercritical CO2 drying, or any environmentally harmful crosslinking chemistries. The reported preparation procedure relies solely on the successive freezing, solvent-exchange, and ambient drying of composite CNF-alginate gels. The presented findings suggest that a highly-porous structure can be preserved throughout the process by simply controlling the ionic strength of the gel. Aerogels with tunable densities (23–38 kg m−3) and compressive moduli (97–275 kPa) can be prepared by using different CNF concentrations. These low-density networks have a unique combination of formability (using molding or 3D-printing) and wet-stability (when ion exchanged to calcium ions). To demonstrate their use in advanced wet applications, the printed aerogels are functionalized with very high loadings of conducting poly(3,4-ethylenedioxythiophene):tosylate (PEDOT:TOS) polymer by using a novel in situ polymerization approach. In-depth material characterization reveals that these aerogels have the potential to be used in not only energy storage applications (specific capacitance of 78 F g−1), but also as mechanical-strain and humidity sensors. © 2020 The Authors.