Large Hydrogen Research Articles

ITER-relevant 600 s steady-state extraction of negative hydrogen ions at the test facility ELISE

Abstract The neutral beam heating system for the future international fusion experiment ITER will be based on RF driven ion sources delivering a large (≈1×2 m2) and homogeneous negative hydrogen or deuterium ion beam of several ten Amperes over up to several hundred seconds. The size scaling experiment ELISE (Extraction from a Large Ion Source Experiment) is an integral part of the R&D road-map towards the ITER neutral beam heating system. Recently, 90 % of the ITER target for the extracted current density was achieved in hydrogen for 600 s, increasing the pulse length over that such current densities are possible by a factor of more than ten. For ten second beam pulses the ITER target current density was achieved. These breakthrough results are made possible by a steady-state capable HV power supply together with an improved version of internal potential rods and a modified topology of the magnetic filter field.

Incident investigation of hydrogen explosion and fire in a residue desulfurization process

A large hydrogen explosion and fire occurred on October 27, 2022 in a residue desulfurization (RDS) process in a refinery in Kaohsiung, Taiwan. RDS is an important process that use hydrogen to convert the sulfur in the fuel into hydrogen sulfide for producing low sulfur fuel. The incident occurred during pressurization of the RDS reactors and downstream coolers by hydrogen. The incident led to significant damages to the downstream coolers and some part of the RDS reactors. Detailed incident investigation was carried out. A reactor effluent air cooler (REAC) in the downstream of RDS reactors was found to be ruptured in the rectangular header box. With security videos, process DCS data, leak and dispersion modelling, and actual damage on the process, it is possible to reproduce the leak rate, size of the initial fireball and damages done to the process. It is also found that the hydrogen leak was accompanied by prompt ignition which is commonly encountered in high-pressure hydrogen services. Recommendations are made to prevent and mitigate any future incident from the RDS process.

Hydrogen storage with gravel and pipes in lakes and reservoirs

Climate change is projected to have substantial economic, social, and environmental impacts worldwide. Currently, the leading solutions for hydrogen storage are in salt caverns, and depleted natural gas reservoirs. However, the required geological formations are limited to certain regions. To increase alternatives for hydrogen storage, this paper proposes storing hydrogen in pipes filled with gravel in lakes, hydropower, and pumped hydro storage reservoirs. Hydrogen is insoluble in water, non-toxic, and does not threaten aquatic life. Results show the levelized cost of hydrogen storage to be 0.17 USD kg−1 at 200 m depth, which is competitive with other large scale hydrogen storage options. Storing hydrogen in lakes, hydropower, and pumped hydro storage reservoirs increases the alternatives for storing hydrogen and might support the development of a hydrogen economy in the future. The global potential for hydrogen storage in reservoirs and lakes is 3 and 12 PWh, respectively. Hydrogen storage in lakes and reservoirs can support the development of a hydrogen economy in the future by providing abundant and cheap hydrogen storage.

Integrating liquid hydrogen infrastructure at airports: Conclusions from an ecosystem approach at Rotterdam The Hague Airport

Aviation is a contributor to global warming. Hydrogen-powered aircraft are seen as an important option to decarbonise parts of commercial aviation. Airports have a pivotal role in facilitating the development of ground infrastructure. This paper provides a broader perspective on the supply and handling of liquid hydrogen, and necessary airport developments, to enable hydrogen-powered aviation. Hydrogen-related airport development projects at Rotterdam The Hague Airport (RTHA) are presented and discussed, and a detailed overview of the airport’s liquid hydrogen (LH2) storage facility is given. To link the ongoing developments to future needs, a LH2 demand scenario for RTHA is determined for the years 2040 and 2050. Based on this demand, analysis of levelised cost of hydrogen for relevant value chains were conducted. This study exemplifies that the LH2 value chain for an airport depends on individual characteristics of the airport and its surroundings. The hydrogen demand, the airport’s proximity to larger hydrogen hubs (import and/or production hubs) and the availability of local renewable resources, which influence electricity price and hydrogen production and liquefaction costs, are key parameters and heavily influence the airport LH2 value chain. Conceptualisation and future development of hydrogen infrastructure for airport supply should take into account the above factors. LH2 demand at RTHA in the year 2050 is predicted to range between 8–14kt. Under the given electricity price assumptions, local production and liquefaction of hydrogen at the airport is not seen as a viable option, as cost savings can be achieved by making use of the Port of Rotterdam’s large hydrogen production and import cluster nearby. The work shows that trailer-based logistics for both the delivery of LH2 to the airport and subsequent usage of these trailers in the storage and dispensing process at the airport seems the most viable for RTHA (and airports that show similarities). This further indicates that current small-scale LH2 demonstration at airports provides important lessons for scaling up.

Flexibility assessment and aggregation of alkaline electrolyzers considering dynamic process constraints for energy management of renewable power-to-hydrogen systems

In the energy management of renewable power-to-hydrogen (ReP2H) systems, quantifying the flexibility of alkaline electrolyzers (AELs) to respond to fast load-tracking commands and maintain energy balance across various timescales is crucial. However, the flexibility of AELs is subject to electrochemical, and dynamic heat and mass transfer constraints, making them very different, both physically and mathematically, from conventional power system flexibility resources such as energy storage (ES) and electrical vehicles (EVs). Additionally, in large hydrogen plants (HPs), aggregating the flexibility of multiple AELs is necessary. Despite extensive flexibility-related research on power and integrated energy systems, work on the electrolyzers is limited. To address these gaps, this paper presents a flexibility assessment method for AELs. Considering comprehensive nonlinear dynamic process constraints, we establish a flexibility metric based on the maximal/minimal energy an AEL can provide within varying time windows. This metric is additive, facilitating the aggregation of multiple AELs within seconds. By comparing it with the energy demanded by regulatory commands, the feasibility of load-tracking control can be assessed without time-domain simulation. In cases of infeasibility, the cause and required compensation can also be interpreted. Case studies validate the proposed method, and key factors impacting the flexibility of AELs are quantitatively analyzed.

Effect of Ni addition and bath temperature on electroless Cu microstructure in microvia preparation for HDI substrate

In this work, we investigated the microstructure evolution of electroless copper (Cu) deposition under different nickel (Ni) additions and reaction temperatures. It was found that the grain structure of electroless Cu is significantly influenced by the addition of Ni due to its inhibitory effect on Cu self-diffusion, while bath temperature had no impact on the electroless Cu grain growth. Additionally. nanovoids were observed in the electroless layer, primarily at the interface between the Cu trace and electroless layer, which is caused by the attachment of hydrogen bubbles during the electroless Cu reaction. These nanovoids do not affect the epitaxial grain growth in the microvia structure as observed through transmission electron microscopy (TEM). The nanovoids in the electroless Cu under different deposition conditions were also investigated through TEM images with the assistance of ImageJ. We found that the dimension of nanovoids initially increases with the reaction rate, as a result of the higher deposition rate introducing large hydrogen bubbles. However, as the reaction rate further increases, the size of the nanovoids stabilizes because larger hydrogen bubbles more easily escape the surface. This work may offer insights into potential approaches to enhance the quality of electroless Cu deposition for microvia preparation.

Future hydrogen economies imply environmental trade-offs and a supply-demand mismatch

Hydrogen will play a key role in decarbonizing economies. Here, we quantify the costs and environmental impacts of possible large-scale hydrogen economies, using four prospective hydrogen demand scenarios for 2050 ranging from 111–614 megatonne H2 year−1. Our findings confirm that renewable (solar photovoltaic and wind) electrolytic hydrogen production generates at least 50–90% fewer greenhouse gas emissions than fossil-fuel-based counterparts without carbon capture and storage. However, electrolytic hydrogen production could still result in considerable environmental burdens, which requires reassessing the concept of green hydrogen. Our global analysis highlights a few salient points: (i) a mismatch between economical hydrogen production and hydrogen demand across continents seems likely; (ii) region-specific limitations are inevitable since possibly more than 60% of large hydrogen production potentials are concentrated in water-scarce regions; and (iii) upscaling electrolytic hydrogen production could be limited by renewable power generation and natural resource potentials.

Pegylated Viologen Derivatives to Improve Performance of Aqueous Organic Redox Flow Battery

Renewable energy sources like wind and solar power are great alternatives for a clean way to produce electricity but have the inconvenience to fluctuate1. To address this issue and promote the implementation of renewables sources, scientists are developing new ways to store energy while production is at a maximum for a subsequent release when there is demand. Redox flow batteries (RFBs) are the most appropriate solution and are increasingly gaining attention for stationary, large scale electrochemical energy storage2,3. One variation of RFBs are aqueous organic redox flow batteries (AORFBs), where water-soluble organic molecules are use as the redox couple. Viologen type molecules are particularly well-suited as a negative potential species to develop cheaper and better AORFBs with great scalability, reversibility and long-term stability4.In this study, viologen derivatives were synthesized with various N-functional groups to explore the impact of the substituent on their solubility, viscosity and redox potential. We showed that the use of short chains of poly(ethylene glycol) improved the solubility of the viologens derivatives which could lead to batteries with higher capacity. The symmetric viologen (with two identical substituents) provided a great solubility in water and the formal potential was unaffected by the chemical nature of the substituents. We demonstrated that the 1,1’-(bisethylene glycol)-4,4’-bipyridium (PEG2-V-PEG2) showed the most promising properties with a high solubility (2.3 M in 1M KCl) and low viscosity (3.01 mPa*s at 1M). As such, this derivative was selected for further evaluation in an asymmetrical labs-scale RFB prototype cell versus bis(trimethylamoniumpropyl)ferrocene (BTMAP-Fc). The compound was studied at various concentrations to assess the maximum energy density that can be reached and the effect of concentration on cycling life by achieving a comparison to the symmetrical 1,1’-bis(3-sulfonatopropyl)-4,4’-bipyridium (SPr-V-SPr) at 0.5 M. Figure 1: Redox flow battery scheme using Viologen derivative as the negolyte and BTMAP-Fc as the posolyte Reference Shi, X., Qian, Y. and Yang, S. Fluctuation analysis of a complementary wind–solar energy system and integration for large scale hydrogen production. ACS Sustainable Chemistry & Engineering, 8(18), pp.7097-7110. (2020)Sánchez-Díez, E.; Ventosa, E.; Guarnieri, M.; Trovò, A.; Flox, C.; Marcilla, R.; Soavi, F.;Mazur, P.; Aranzabe, E.; Ferret, R., Redox flow batteries: Status and perspective towards sustainable stationary energy storage. Journal of Power Sources, 481, 1-23. (2021)Poullikkas, A., A comparative overview of large-scale battery systems for electricity storage. Renewable and Sustainable energy reviews, 27, pp.778-788. (2013)Gentil, S., Reynard, D. and Girault, H.H. Aqueous organic and redox-mediated redox flow batteries: a review. Current Opinion in Electrochemistry, 21, pp.7-13. (2020) Figure 1

A multi-objective planning tool for the optimal supply of green hydrogen for an industrial port area decarbonization

This study addresses the challenge of decarbonizing highly energy-intensive Industrial Port Areas (IPA), focusing on emissions from various sources like ship traffic, warehouses, buildings, cargo handling equipment and hard-to-abate industry, typically hosted in port areas. The analysis and proposal of technological solutions and their optimal integration in the context of IPA is a topic of growing scientific interest with considerable social and economic implications. Representing the main novelties of the work, this study introduces (i) the development of a novel IPA energy and green hydrogen hub located in a tropical region (Singapore); (ii) a multi-objective optimization approach to analyse, synthesize and optimize the design and operation of the hydrogen and energy hub, with the aim of supporting decision-making for decarbonization investments. A sensitivity analysis identifies key parameters affecting optimization results, indicating that for large hydrogen demands, imported ammonia economically outperforms other green hydrogen carriers. Conversely, local hydrogen production via electrolysis becomes economically viable when the capital cost of alkaline electrolyser drops by at least 30 %. Carbon tax influences the choice of green hydrogen, but its price variation mainly impacts system operation rather than design. Fuel cells and batteries are not considered economically feasible solutions in any scenario.

Integration of a Hydrogen Storage Cavern into the Carbon2Chem® Project

AbstractUnderground salt caverns allow large hydrogen storage capacities at low specific costs. Such storage is required to balance fluctuating hydrogen supply and constant demand of large consumers as a methanol plant from the Carbon2Chem® project. The geological and technical feasibility for developing up to 168 Mio. m3 (n.c.) or 595 GWh of working gas capacity until 2040 at a location in the Lower Rhine Bay is described. Various options for realization as well as a novel process for cavern leaching parallel to hydrogen storage operation are evaluated. Further work is required including geological exploration and optimization of brine production. The main hurdles for investment decisions are the political uncertainties on the hydrogen storage market design and on the ramp‐up of the hydrogen market.

Low-temperature hydrogen release exceeding 7 wt% from LiBH4-mannitol composites

Among conventional hydrogen storage materials, LiBH4 has been regarded as one of the best hydrogen transporters due to its relatively large hydrogen capacities. However, because of its extraordinarily high dehydrogenation temperatures, LiBH4 was not suitable for hydrogen storage due to its stable thermodynamic features. Herein, we present a novel approach to LiBH4 that uses solid-state multi-hydroxyl mannitol as a reactant, regulating hydrogen release below 69.9 °C. More than 7 wt% H2 could be released with ultra-fast rates at 140 °C from the LiBH4-mannitol composite. XRD, FTIR, and SEM tests revealed that the reaction between mannitol (Hδ+) and LiBH4 (Hδ−) to produce hydrogen was accompanied by the generation of large amounts of heat in situ, which further promoted the decomposition of LiBH4 for hydrogen production, exceeding the theoretical dehydrogenation amount of Hδ+- Hδ− reaction. This work indicates possibilities for the development of fast and easy high-capacity hydrogen generation systems based on complex hydrides.

Imparting Ultrahigh Strength to Polymers via a New Concept Strategy of Construction of up to Duodecuple Hydrogen Bonding among Macromolecular Chains.

Interconnecting macromolecules via multiple hydrogen bonds (H-bonds) can simultaneously strengthen and toughen polymers, but material synthesis becomes extremely difficult with increasing number of H-bonding donors and acceptors; therefore, most reports are limited to triple and quadruple H-bonds. Herein, this bottleneck is overcome by adopting a quartet-wise approach of constructing H-bonds instead of the traditional pairwise method. Thus, large multiple hydrogen bonds can be easily established, and the supramolecular interactions are further reinforced. Especially, when such multiple H-bond motifs are embedded in polymers, four macromolecular chains-rather than two as usual-are tied, distributing the applied stress over a larger volume and more significantly improving the overall mechanical properties. Proof-of-concept studies indicate that the proposed intermolecular multiple H-bonds (up to duodecuple) are readily introduced in polyurethane. A record-high tensile strength (105.2MPa) is achieved alongside outstanding toughness (352.1 MJ m-3), fracture energy (480.7 kJ m-2), and fatigue threshold (2978.4 J m-2). Meantime, the polyurethane has acquired excellent self-healability and recyclability. This strategy is also applicable to nonpolar polymers, such as polydimethylsiloxane, whose strength (15.3MPa) and toughness (50.3 MJ m-3) are among the highest reported to date for silicones. This new technique has good expandability and can be used to develop even more and stronger polymers.

Large scale photocatalytic hydrogen production from original natural Yellow River water and solvent (0.35 M Na2S and 0.25 M Na2SO3) over nano Cu@graphdiyne/Zn0.5Cd0.5S photocatalyst

The Zn0.5Cd0.5S material holds significant promise for employment in photocatalytic hydrogen evolution. However, it face an issue of photogenerated electrons, resulting in an elevated rate of photogenerated electron-hole recombination. To tackle this challenge, we propose a remedy utilizing a dual built-in electric field. This is accomplished by leveraging the distinct properties of graphdiyne, which can serve as either an electron donor or acceptor. To create the dual built-in electric field, we first grow a thin layer of graphdiyne on the surface of Nano Cu, forming the first layer. The subsequent layer consists of another graphdiyne thin layer combined with Zn0.5Cd0.5S. Upon exposure to light, Zn0.5Cd0.5S produces a substantial number of photogenerated electrons, which can swiftly move under the influence of the dual built-in electric field. In experiments conducted under square meter conditions with a reaction environment of 0.35 M Na2S and 0.25 M Na2SO3, hydrogen evolution reached a production quantity of 106,689 µmol within 30 h. In another experiment conducted with original natural water from the Yellow River, the production quantity amounted to 334 µmol within 84 h. Under 5 W simulated sunlight and 108 hours in pure water, 178 µmol of hydrogen and 50 µmol of oxygen were generated.

Damping wing-like features in the stacked Ly α forest: Potential neutral hydrogen islands at z < 6

ABSTRACT Recent quasar absorption line observations suggest that reionization may end as late as $z \approx 5.3$. As a means to search for large neutral hydrogen islands at $z\ \lt\ 6$, we revisit long dark gaps in the Ly $\beta$ forest in Very Large Telescope/X-Shooter and Keck/Echellette Spectrograph and Imager quasar spectra. We stack the Ly $\alpha$ forest corresponding to both edges of these Ly $\beta$ dark gaps and identify a damping wing-like extended absorption profile. The average redshift of the stacked forest is $z=5.8$. By comparing these observations with reionization simulations, we infer that such a damping wing-like feature can be naturally explained if these gaps are at least partially created by neutral islands. Conversely, simulated dark gaps lacking neutral hydrogen struggle to replicate the observed damping wing features. Furthermore, this damping wing-like profile implies that the volume-averaged neutral hydrogen fraction must be $\langle x_{\rm H\,{\small {I}}} \rangle \ge 6.1 \pm 3.9~{{\ \rm per\ cent}}$ at $z = 5.8$. Our results offer robust evidence that reionization extends below $z=6$.

Research on effective thermal conductivity of hollow glass microspheres under vacuum at low temperature

As insulation materials with excellent thermal insulation properties, high robustness, and low maintenance costs, hollow glass microspheres (HGM) are gradually being applied in large liquid hydrogen storage tanks. However, the low-temperature insulation mechanism of HGMs is still unknown, and the insulation effect of HGMs of different types under various conditions has been neglected in recent decades. In this study, an existing theoretical model was improved by considering the gas thermal conductivity equations under various pressure intervals, and an experimental platform was built based on the steady vertical heat flux method to measure the effective thermal conductivities of three commercially available HGM models. The effective thermal conductivities of HGM models K1, T15, and HL20 at 0.1 Pa were 10, 8.9, and 7.6 mW/(m·K), respectively. The values decreased to 2.5, 2.9, and 2.0 mW/(m·K), respectively, when the cold boundary temperature was 90 K. To analyse the effect of the HGM physical parameters and environment on the HGM insulation, the thermal conductivities were calculated using the derived theoretical model. It was found that continuing to reduce the pressure after the ambient pressure reached 10 Pa hardly improved the insulation performances of the HGMs. The radiative heat transfer was very sensitive to temperature changes and jointly dominated the heat transfer with integrated thermal conductivity in the low-temperature region. In summary, HGMs are advanced vacuum-insensitive insulation materials, which have great potential in the field of cryogenic liquid storage and transportation.

Crack propagation characteristics and fatigue life of the large austenitic stainless steel hydrogen storage pressure vessel

Hydrogen-induced cracking or embrittlement can have a substantial and severe impact on the fatigue life of large austenitic stainless steel hydrogen storage pressure vessels. In this study, a dynamic model for the plastic zone in the crack tip considering the hydrogen diffusion was established and a correction factor for the stress intensity factor of the hydrogen storage pressure vessel was proposed for 316L stainless steel, which is commonly used pressure vessel material. The crack propagation characteristics and fatigue life of the stainless steel vessel were investigated. The results indicated that the shortest fatigue life under hydrogen pressure occurs at the intersection of the vent nozzle and the vessel head. The hydrogen environment not only reduces vessel service life but also makes the influence of pressure on cracks propagation more pronounced. It leads to a significant reduction in the fatigue life of pressure vessels when overpressure happens during operation. These research findings are valuable for the accurate assessment of the vessel fatigue life and improving the quality of large hydrogen storage vessel structures.

Hydrogen diffusion and precipitation influenced by non-uniformly distributed stress in zirconium alloy with different textures

Hydrogen embrittlement is a crucial factor for the performance and life of zirconium alloys in nuclear industry. During service, the residual stress in the materials induces re-distribution of hydrogen, which further affects the fracture behavior. This study is dedicated to investigating the hydrogen diffusion and precipitation under the meso‑scale non-uniform deformation field. The texture effect of hydrogen behavior was examined by considering three different texture scenarios: grains with c-axis deviating from the tensile direction of random angle, 0°and 90° The cases were termed Random, T000, and T0900 respectively. The crystal plasticity finite element method (CPFEM) was employed to simulate the stress-assisted diffusion of hydrogen atoms in the polycrystalline zirconium alloy. It is determined that the T0900 case gets fewer regions with higher hydrostatic stress gradient, which helps relieve the hydrogen concentration. Compared to the T0900 texture, the interaction between soft and hard grains in the Random and T000 texture conditions results in higher stress gradient and severe hydrogen concentration. Statistical analysis was conducted and the hydrogen concentration in the three textures presents a normal distribution. T0900 gets a relatively lower overall hydrogen concentration while the T000 texture gets severe hydrogen concentration larger than 120 wt.ppm. In Random and T000 textures, hydrogen tends to accumulate at grain interior and boundaries, and continuous hydrogen concentration band forms along adjacent GBs. The T0900 scenario is free of large continuous hydrogen concentration zones, which helps reduces the adverse effects of hydrogen diffusion and precipitation. The findings of the work advance the understanding of the hydrogen behavior affected by stress heterogeneity and texture, which is the basis for the exploration of hydrogen embrittlement.

In Operando X-ray Spectroscopic and DFT Studies Revealing Improved H2 Evolution by the Synergistic Ni-Co Electron Effect in the Alkaline Condition.

The different electrolyte conditions, e.g., pH value, for driving efficient HER and OER are one of the major issues hindering the aim for electrocatalytic water splitting in a high efficiency. In this regard, seeking durable and active HER electrocatalysts to align the alkaline conditions of the OER is a promising solution. However, the success in this strategy will depend on a fundamental understanding about the HER mechanism at the atomic scale. In this work, we have provided thorough understanding for the electrochemical HER mechanisms in KOH over Ni- and Co-based hollow pyrite microspheres by in operando X-ray spectroscopies and DFT calculations, including NiS2, CoS2, and Ni0.5Co0.5S2. We discovered that the Ni sites in hollow NiS2 microspheres were very stable and inert, while the Co sites in hollow CoS2 microspheres underwent reduction and generated Co metallic crystal domains under HER. The generation of Co metallic sites would further deactivate H2 evolution due to the large hydrogen desorption free energy (-1.73 eV). In contrast, the neighboring Ni and Co sites in hollow Ni0.5Co0.5S2 microspheres exhibited the electronic interaction to elevate the reactivity of Ni and facilitate the stability of Co without structure or surface degradation. The energy barrier in H2O adsorption/dissociation was only 0.73 eV, followed by 0.06 eV for hydrogen desorption over the Ni0.5Co0.5S2 surface, revealing Ni0.5Co0.5S2 as a HER electrocatalyst with higher durability and activity than NiS2 and CoS2 in the alkaline medium due to the synergy of neighboring Ni and Co sites. We believe that the findings in our work offer a guidance toward future catalyst design.

Development and calibration of a bio-geo-reactive transport model for UHS

The increased share of renewable energy sources will lead to large fluctuations in energy availability and increases energy storage’s significance. Large-scale hydrogen storage in the subsurface may become a vital element of a future sustainable energy system because stored hydrogen becomes an energy carrier available on demand. Large hydrogen amounts can be stored in porous formations such as former gas fields or gas storages, while caverns can contribute with high deliverability. However, the storage of hydrogen induces unique processes in fluid-fluid and rock-fluid interactions (for example, bio- and geochemical reactions), which may affect the efficiency of the storage. In the present study, a mathematical model describing the two-phase multicomponent flow in porous media, including bio- and geochemical reactions, is developed to predict these hydrogen-related processes. The proposed model extends an existing model in the open source simulator DuMux describing the bio-reactive transport process considering methanation and sulfate-reduction by geochemical reactions. Significant attention is placed on the reduction from pyrite-to-pyrrhotite coming with the generation of harmful hydrogen sulfide. This reaction is calibrated by developing a kinetic model in DuMux that mimics the observations of reactor experiments from literature. The developed and calibrated model is afterwards used for simulation runs on field scale to assess the impact on Underground Hydrogen Storage (UHS) operations. The developed kinetic model describes the reduction from pyrite-to-pyrrhotite in agreement with the observations in the literature, whereby particular focus was placed on the hydrogen sulfide production rate. The consecutive implementation of the transport model in DuMux on field scale, including the bio- and geochemical reactions, shows the potential permanent hydrogen losses caused by reactions and temporary ones induced by gas-gas mixing with the initial and cushion gas.

Ion‐Conducting Molecular‐Grafted Sustainable Cellulose Quasi‐Solid Composite Electrolyte for High Stability Solid‐State Lithium‐Metal Batteries

AbstractCellulose‐based solid electrolyte possesses the characteristics of low cost, high strength, and sustainability, and has great potential in the field of solid‐state lithium metal batteries. However, the large hydrogen bonds between cellulose molecules make the molecular chains tightly arranged, and hinder the ion conduction, seriously limiting its further development. Herein, an ion‐conducting molecular grafting strategy is proposed for the fabrication of cellulose acetate quasi‐solid composite electrolyte (CLA‐CN‐LATP QCE) with a superior ionic conductivity of 1.25 × 10−3 S cm−1 at room temperature. Benefited from grafted functional molecules, the assembled symmetrical battery exhibits low polarization voltage and highly stable lithium stripping/plating cycling of more than 1200 h at 0.1 mA cm−2 current density. Moreover, it endows LFP|CLA‐CN‐LATP QCE|Li battery with excellent long‐cycle stability of 1500 cycles at 0.5 C and 25 °C and superior capacity retention of 92.1%. Importantly, this work provides an effective strategy for further opening the ion transport channel between cellulose molecular chains and improving the interface properties of electrolytes and electrodes.