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Copyright of Rare Metals is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

A ladder‐type rigid‐coplanar polymer with highly ordered molecular arrangement has been designed via a covalent cycloconjugation conformational strategy. Benefitting from the extended π‐electron delocalization in the highly aromatic ladder‐type polymeric backbone, the prepared polymer exhibits fast intra‐chain charge transport along the polymeric chain, realizing extraordinary proton‐storage capability in aqueous proton batteries.Affordable and safe aqueous proton batteries (APBs) with unique "Grotthuss mechanism," are very significant for advancing carbon neutrality initiatives. While organic polymers offer a robust and adaptable framework that is well‐suited for APB electrodes, the limited proton‐storage redox capacity has constrained their broader application. Herein, a ladder‐type polymer (PNMZ) has been designed via a covalent cycloconjugation conformational strategy that exhibits optimized electronic structure and fast intra‐chain charge transport within the high‐aromaticity polymeric skeleton. As a result, the polymer exhibits exceptional proton‐storage redox kinetics, which are evidenced by in‐operando monitoring techniques and theoretical calculations. It achieves a remarkable proton‐storage capacity of 189 mAh g−1 at 2 A g−1 and excellent long‐term cycling stability, with approximately 97.8 % capacity retention over 10,000 cycles. Finally, a high‐performance all‐polymer APB device has been successfully constructed with a desirable capacity retention of 99.7 % after 6,000 cycles and high energy density of 56.3 Wh kg−1. [ABSTRACT FROM AUTHOR]

Developing multicomponent composite materials with delicate morphology and tailored structure is of vital importance for designing advanced sodium‐ion batteries (SIBs). Herein, a confinement‐structured Fe2Mo3O8@C@MoS2 with local‐expanded interlayer spacing is designed via high‐temperature phase transition from FeMoO4 to Fe2Mo3O8 and the tactically introducing dopamine molecules into the interlayer of MoS2 nanosheets. By analysis of the in situ generated solid electrolyte interphase film in different electrolytes, the favorable compatibility of Fe2Mo3O8@C@MoS2 in ether‐based electrolytes is well illustrated. Importantly, the sodium storage mechanism and detailed structural evolution of Fe2Mo3O8 are established for the first time by in situ X‐ray diffraction. Furthermore, theoretical calculations indicate the unique structure facilitates internal charge transfer and enhances Na+ adsorption ability. Thanks to the unique confinement structure, local‐expanded interlayers and robust framework, the Fe2Mo3O8@C@MoS2 composite achieves a high reversible specific capacity of 636 mAh g‒1 at 0.1 A g‒1, excellent rate capability (301 mAh g‒1 at 5.0 A g‒1) and ultralong cycling stability (365 mAh g–1 after 6000 cycles at 2.0 A g–1). The study provides an essential understanding of the Na storage mechanism of Fe2Mo3O8 and a promising strategy for constructing high‐performance anodes for SIBs. [ABSTRACT FROM AUTHOR]

Rational element doping is demonstrated as an effective strategy to optimize crystal stability and enhance the electronic conductivity of Prussian blue analogs (PBAs) to achieve a satisfactory sodium storage performance. However, unraveling the dopant selection principles is still a big challenge. Herein, the integrated crystal orbital Hamilton population (ICOHP) function is adopted to evaluate the strength of chemical bonds of N‐transition metals (N‐TM) and guide the dopant selection. Among the series of ICOHP values for N‐TM (TM = Mn, Fe, Co, Ni, Cu, Zn), the Cu─N bond exhibits the lowest ICOHP value, which indicates that Cu doping can improve the stability of PBAs compared to other dopants. Experimentally, among TM‐substituted Fe‐based PBAs (TMFeHCFs), the as‐prepared sample with 20 at.% Cu doping (CuFeHCF‐2) exhibits the best cycling performance, with a capacity retention of 83.5% after 400 cycles at 1 C, which is consistent with the theoretical calculation results. In addition, in situ XRD and in situ, Raman reveal a highly reversible monoclinic‐cubic two‐phase conversion and redox‐active pairs, respectively. This study provides valuable guidelines for dopant selection to enhance the performance of PBAs cathodes. [ABSTRACT FROM AUTHOR]

Hard Carbon is the most widely used negative electrode material for sodium-ion batteries today. Achieving high storage capacity and increasing the plateau capacity, as opposed to the sloping profile, are crucial for enhancing energy density of the full cells. While several publications address the synthesis of hard carbon, the economic viability for commercial scale-up hinges on the choice of precursors. In this study, we report the electrochemical properties of hard carbon derived from two biomass precursors, sugarcane waste (bagasse) and corn waste, and compare their performances with commercially available hard carbon. The hard carbon derived from bagasse delivers a capacity of 307 mAh/g at C/10 rate and retains approximately 234 mAh/g at 3C discharge rate. We integrate surface area, pore size distribution, Raman spectroscopy, small-angle X-ray and neutron scattering data to elucidate the sodium storage mechanism in these hard carbon samples. Correlated graphitic domains with hexagonal ordering along with fractal like agglomeration of the nanosheets are quantified. The high plateau capacity of the bagasse-derived hard carbon is attributed to the characteristic morphology and size distribution of the nanosheets and their nature of agglomeration.

CO2 -EGR technology, as a critical element within the framework of CCUS (CO2 capture, utilization, and storage), is recognized for its substantial potential in accomplishing the dual objectives of reducing carbon emissions and augmenting natural gas production. The mechanisms through which CO2 enhances natural gas recovery and storage were comprehensively outlined, along with an examination of the associated potential and evaluation methodologies. Key findings indicate that CO2 improves natural gas recovery rates through mechanisms such as physical property differences, competitive adsorption, screening displacement, continuous convection displacement, restoration of gas reservoir pressure, and inhibition of water invasion. Additionally, the sealing mechanisms of CO2 in gas reservoirs encompass structural sealing, residual gas sealing, dissolution sealing, and mineralization sealing. The evaluation methods for CO2 -enhanced natural gas recovery rates include numerical simulation, theoretical analysis, and physical experiments. Similarly, methods for assessing CO2 storage in gas reservoirs involve the effective volume method, material balance method, numerical simulation, and theoretical evaluation. While the potential of CO2 to enhance natural gas recovery is established, and preliminary evaluation methods are outlined, current applicability remains limited. Further refinement is deemed essential, particularly in consideration of the geological characteristics of natural gas reservoirs in China, to enhance the accuracy of storage assessments. Continuous research efforts are acknowledged as imperative to broaden the scope of application and optimize evaluation methodologies within this field. [ABSTRACT FROM AUTHOR]

Copyright of Industrial Minerals & Processing / Huagong Kuangwu yu Jiagong is the property of Industrial Minerals & Processing Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In this study we investigate the Na insertion process occurring in the "free carbon" phase embedded in two different SiCN(O) matrices with operando Raman spectroscopy. The two SiCN(O) samples have been prepared using two different thermal treatments carried out at 1000 °C (SiCN(O)1000) and 1400 °C (SiCN(O)1400). X‐ray diffraction as well as argon adsorption reveal significant structural and morphological differences between the materials. SiCN(O)1000 shows an amorphous nature whereas SiCN(O)1400 reveals the presence of crystalline β‐SiC, accompanied by a notable increase in surface area (from 56.7 m2/g to 331 m2/g) and micropore volume (from 0.02 cm3/g to 0.12 cm3/g). These alterations in the ceramic matrix due to thermal treatment affect significantly the electrochemical performance with initial de‐sodiation capacities of 112.4 mAh/g and 52.3 mAh/g for SiCN(O)1000 and SiCN(O)1400, respectively. Operando Raman spectroscopy, carried out during the sodiation and de‐sodiation of the SiCN(O) ceramics, reveals the microstructural changes occurring to the "free carbon" phase during the storage of sodium ions. As sodium is inserted, a shift in the G‐band position is observed in both the samples from about 1600 cm−1 to 1555 cm−1, with a concomitant decrease of the D‐band intensity and the distance between defects (LD) growing from 7.5 nm to 17.5 nm. Upon de‐sodiation, SiCN(O)1400 exhibits an inferior storage reversibility compared to SiCN(O)1000. This may be attributed to the irreversible sodium trapping occurring in SiCN(O)1400, highlighted by the reduced efficiency of the electrochemical process. [ABSTRACT FROM AUTHOR]

[Display omitted] Aqueous zinc ion batteries (AZIBs) have attained enormous attention in the last few years. The cathode materials of aqueous zinc ion batteries play a vital effect in their electrochemical and battery properties. In this manuscript, Sandwich-like MXene@Na 2 V 6 O 16 ·3H 2 O (NVO@MXene) heterostructure was successfully prepared by the combination and cooperation of the layer lattice structure of Na 2 V 6 O 16 ·3H 2 O and the high conductivity of MXene. When used as the cathode material for AZIBs, NVO@MXene demonstrates preeminent rate capability and excellent reversible capacity of 175 mAh/g after 3000 cycles at 5 A/g with a retention rate of 88.9 % of initial discharge capacity. The outstanding battery performance can be attributed to the MXene layers with high conductivity for accelerating the ion diffusion rate and reducing the agglomeration of Na 2 V 6 O 16 ·3H 2 O nanowires during the (dis)charge process. Meanwhile, the stable layered structure of Na 16 V 6 O 6 ·3H 2 O with wide interlamellar spacing (d = 7.9 Å) is also favorable for the s fast intercalation/deintercalation of Zn2+. Finally, ex-situ X-ray diffraction and X-ray photoelectron spectroscopy were applied to study and reveal the energy storage mechanism of this novel material for aqueous zinc ion batteries. [ABSTRACT FROM AUTHOR]

Traditional optimization algorithms often have the problems of slow convergence and poor accuracy when facing complex situations. Therefore, a parameter optimization method based on multi-modal butterfly optimization algorithm is proposed for parameter adjustment of support vector machine and infinite impulse response digital filter. By introducing storage mechanism strategy, the accelerated detection mechanism and purification program strategy, the global searching ability and solving efficiency of the algorithm are improved. The results showed that the improved multi-modal butterfly optimization algorithm reached its optimal solution in the fifth iteration, and the objective function value reached its minimum without changing. The precision and recall of this algorithm were above 0.9, and the variance was close to 0. This algorithm successfully solved 942 epochs with a success rate of 93.314%. The total solution time was 14.338 seconds, and the average solution time was 0.014 seconds. The improved multi-modal butterfly optimization algorithm showed excellent performance in optimizing parameters, effectively improving parameter optimization performance, and showed high efficiency, stability, and reliability. This study is helpful to promote optimization algorithms and provide more efficient and reliable methods for solving practical problems.

Sisal fiber exhibits a fibrous and porous structure with significant surface roughness, making it highly suitable for storing phase change materials (PCMs). Its intricate morphology further aids in mitigating the risk of PCM leakage. This research successfully employs vacuum adsorption to encapsulate paraffin within sisal fiber, yielding a potentially cost-effective, durable, and environmentally friendly phase change energy storage medium. A systematic investigation was carried out to evaluate the effects of sisal-to-paraffin mass ratio, fiber length, vacuum level, and negative pressure duration on the loading rate of paraffin. The experimental results demonstrate that a paraffin loading rate of 8 wt% can be achieved by subjecting a 3 mm sisal fiber to vacuum adsorption with 16 wt% paraffin for 1 h at −0.1 MPa. Through the utilization of nano-CT imaging enhancement technology, along with petrographic microscopy, this study elucidates the mechanism underlying paraffin storage within sisal fiber during vacuum adsorption. The observations reveal that a substantial portion of paraffin is primarily stored within the pores of the fiber, while a smaller quantity is firmly adsorbed onto its surface, thus yielding a durable phase change energy storage medium. The research findings contribute to both the theoretical foundations and the available practical guidance for the fabrication and implementation of paraffin/sisal fiber composite phase change energy storage mediums. [ABSTRACT FROM AUTHOR]

This reviews the latest progress in the host structure, storage mechanism, electrolytes, and devices of aqueous ammonium ion storage devices from a structural perspective, and proposes research prospects and promising improvement strategies. [Display omitted] • Summarized the host materials of aqueous ammonium ions from a structural perspective, including storage mechanisms and improvement strategies. • The electrolytes used for NH 4 + storage was classified based on storage type and concentration, and the problems and solutions faced were summarized. • Summarized the advanced progress of various NH 4 + storage devices using NH 4 + as carriers. Aqueous ammonium ion energy storage devices have received widespread attention recently due to their high safety, fast diffusion kinetics, and unique tetrahedral structure with abundant charge carriers (NH 4 +) resources. Although many NH 4 + storage electrode materials have been frequently proposed, there are still face explorations and challenges in terms of performance improvement and storage mechanisms. Therefore, there is an urgent need to develop high-performance NH 4 + storage electrode materials and explore deeper mechanisms. This review comprehensively classifies and compares NH 4 + storage electrode materials from a structural perspective, and reviews the influence of electrolyte composition and concentration on NH 4 + storage systems. In addition, this review also elaborates on the current limitations and possible solutions. Finally, common NH 4 + storage devices are summarized, and their future development prospects and challenges are discussed. [ABSTRACT FROM AUTHOR]

Cation additives can efficiently enhance the total electrochemical capabilities of zinc-ion hybrid capacitors (ZHCs). However, their energy storage mechanisms in zinc-based systems are still under debate. Herein, we modulate the electrolyte and achieve dual-ion storage by adding magnesium ions. And we assemble several Zn//activated carbon devices with different electrolyte concentrations and investigate their electrochemical reaction dynamic behaviors. The zinc-ion capacitor with Mg2+ mixed solution delivers 82 mAh·g−1 capacity at 1 A·g−1 and maintains 91% of the original capacitance after 10000 cycling. It is superior to the other assembled zinc-ion devices in single-component electrolytes. The finding demonstrates that the double-ion storage mechanism enables the superior rate performance and long cycle lifetime of ZHCs. [ABSTRACT FROM AUTHOR]

The sluggish kinetics in traditional graphite anode greatly limits its fast‐charging capability, which is critically important for commercialization of potassium ion batteries (PIBs). Hard carbon possesses randomly oriented pseudo‐graphitic crystallites, enabling homogeneous reaction current and superior rate performance. Herein, a series of hybrid anodes with different hard carbon/graphite ratios are prepared by uniformly mixing graphite and hard carbon with ball‐milling. Comprehensive experimental results in combination phase‐field simulations reveal that the hybrid anode possesses a homogeneous reaction current and an intriguing potential difference between K+‐adsorbed hard carbon and non‐potassiated graphite. The homogeneous reaction current in the hybrid anode promotes sufficient utilization of electrode material, leading to an increase in the reversible capacity. The present potential difference between K+‐adsorbed hard carbon and non‐potassiated graphite provides an additional electric field force that facilitates the diffusion of K+ from hard carbon into the nearest neighbor graphite. All these together, emphasize the synergistic effects between hard carbon and graphite in hybrid anodes toward satisfactory rate and cycling performance. The hybrid strategy proposed here is compatible with the commercial battery manufacturing, offering a practical pathway for the development of high‐performance PIBs. [ABSTRACT FROM AUTHOR]

Raman spectroscopy is a non-destructive analytical technique that provides detailed information on the chemical structure and molecular interactions of a sample. In situ spectroelectrochemistry combined by spectroscopy and conventional electrochemical methods is a powerful technique for dynamically detecting the structure and phase composition of electrode materials. It has broad application prospects in energy storage and provides information on the micro-structure at the electrode interface. Raman spectroscopy can effectively characterize the change of various cathodic materials and complex ions in aluminum chloride-based electrolytes of rechargeable aluminum-ion batteries (AIBs) during the charging and discharging processes in situ. Combined with characterization techniques, such as XRD and XPS, Raman spectroscopy can effectively reveal the energy storage mechanism of rechargeable aluminum-ion batteries, including the study of electrolytes and electrode materials and in situ monitoring of electrode surface reactions. The study of the nature of electrode materials and interface structures can guide the optimal design of battery materials and microstructures, and the in-situ exploring of electrode surface reactions can help to conduct an in-depth study of the mechanism of electrode interface reactions for guiding the structural optimization of cathode materials and promoting the development of rechargeable aluminum-ion batteries. [ABSTRACT FROM AUTHOR]

The development history of carbon capture, utilization and storage for enhanced oil recovery (CCUS-EOR) in China is comprehensively reviewed, which consists of three stages: research and exploration, field test and industrial application. The breakthrough understanding of CO2 flooding mechanism and field practice in recent years and the corresponding supporting technical achievements of CCUS-EOR project are systematically described. The future development prospects are also pointed out. After nearly 60 years of exploration, the theory of CO2 flooding and storage suitable for continental sedimentary reservoirs in China has been innovatively developed. It is suggested that C7–C15 are also important components affecting miscibility of CO2 and crude oil. The mechanism of rapid recovery of formation energy by CO2 and significant improvement of block productivity and recovery factor has been verified in field tests. The CCUS-EOR reservoir engineering design technology for continental sedimentary reservoir is established. The technology of reservoir engineering parameter design and well spacing optimization has been developed, which focuses on maintaining miscibility to improve oil displacement efficiency and uniform displacement to improve sweep efficiency. The technology of CO2 capture, injection and production process, whole-system anticorrosion, storage monitoring and other whole-process supporting technologies have been initially formed. In order to realize the efficient utilization and permanent storage of CO2, it is necessary to take the oil reservoir in the oil-water transition zone into consideration, realize the large-scale CO2 flooding and storage in the area from single reservoir to the overall structural control system. The oil reservoir in the oil-water transition zone is developed by stable gravity flooding of injecting CO2 from structural highs. The research on the storage technology such as the conversion of residual oil and CO2 into methane needs to be carried out.

Prussian blue analogues (PBAs) have been regarded as promising cathode materials for alkali‐ion batteries owing to their high theoretical energy density and low cost. However, the high water and vacancy content of PBAs lower their energy density and bring safety issues, impeding their large‐scale application. Herein, a facile "potassium‐ions assisted" strategy is proposed to synthesize highly crystallized PBAs. By manipulating the dominant crystal plane and suppressing vacancies, the as‐prepared PBAs exhibit increased redox potential resulting in high energy density up to ≈450 Wh kg−1, which is at the same level of the well‐known LiFePO4 cathodes for lithium‐ion batteries. Remarkably, unconventional highly‐reversible phase evolution and redox‐active pairs were identified by multiple in situ techniques for the first time. The preferred guest‐ion storage sites and migration mechanism were systematically analysed through theoretical calculations. We believe these results could inspire the design of safe with high energy density. [ABSTRACT FROM AUTHOR]

The Fe/Fe 3 C@NC exhibits excellent capacitive deionization performance as a Cl-storage electrode. Its storage mechanism is a surface redox pseudocapacitance induced by the reversible conversion of Fe2+/Fe3+ couple occurring on or near the surface. [Display omitted] • The Fe/Fe 3 C@NC composite is fabricated by gel-sol method combined with Fe-catalyzed carbonization. • The Fe/Fe 3 C@NC is employed as a Cl-storage electrode for capacitive deionization. • The Fe/Fe 3 C@NC delivers an excellent Cl– adsorption capacity of 102.3 mg g−1. • The Fe/Fe 3 C@NC shows a stable Cl– capacity of 68.5 mg g−1 over 60 cycles. • The Cl– storage mechanism is surface redox pseudo-capacitance of Fe2+/Fe3+ couple. The practical application of carbon anode in capacitive deionization (CDI) is greatly hindered by their poor adsorption capacity and co-ion effect. Herein, an N -doped graphene-like carbon (NC) decorated with Fe/Fe 3 C nanoparticles composite (Fe/Fe 3 C@NC) with large specific surface area and plentiful porosity is fabricated via a facile and scalable method, namely sol–gel method combined with Fe-catalyzed carbonization. As expected, it exhibits superior CDI performance as a Cl-storage electrode, with Cl- adsorption capacity as high as 102.3 mg g−1 at 1000 mg L−1 Cl- concentration and 1.4 V voltage, and a stable capacity of 68.5 mg g−1 for 60 cycles in 500 mg L−1 Cl– concentration and 100 mA g−1 current density. More importantly, on the basis of electrochemical tests, ex-situ X-ray diffraction, ex-situ X-ray photoelectron spectroscopy (XPS), and XPS analysis with argon ion depth etching, it is revealed that the chlorine storage mechanism of the Fe/Fe 3 C@NC electrode is dominated by the surface-related redox pseudocapacitance behavior of Fe2+/Fe3+ couple occurring on or near the surface, enabling fast and reversible ion storage. This work proposes an economical and environmentally friendly general method for the design and development of high-performance Cl-storage electrodes for CDI, and offers an in-depth insight into the Cl- storage mechanism of Fe decorated carbon electrodes, further promoting the development of CDI technology. [ABSTRACT FROM AUTHOR]

Based on the intercalation reaction, molybdenum trioxide has become an attractive cathode material for rechargeable ion batteries owing to its high theoretical capacity and layered structure. This review summarizes the recent research progress of molybdenum trioxide‐based cathode in non‐aqueous lithium, magnesium, calcium‐ion batteries, aqueous zinc, hydrogen, and aluminum‐ion batteries, focusing on the energy storage mechanism, existing problems, and optimization strategies in rechargeable ion batteries. Finally, the perspectives about challenges and future further development directions of molybdenum trioxide cathode in electrochemical energy storage are proposed. This review will comprehensively summarize molybdenum trioxide as a cathode in rechargeable ion batteries and clarify its practical application prospects for sustainable development. [ABSTRACT FROM AUTHOR]

As anode material for sodium ion batteries (SIBs), biomass-derived hard carbon has attracted a great deal of attention from researchers because of its renewable nature and low cost. However, its application is greatly limited due to its low initial Coulomb efficiency (ICE). In this work, we employed a simple two-step method to prepare three different structures of hard carbon materials from sisal fibers and explored the structural effects on the ICE. It was determined that the obtained carbon material, with hollow and tubular structure (TSFC), exhibits the best electrochemical performance, with a high ICE of 76.7%, possessing a large layer spacing, a moderate specific surface area, and a hierarchical porous structure. In order to better understand the sodium storage behavior in this special structural material, exhaustive testing was performed. Combining the experimental and theoretical results, an "adsorption-intercalation" model for the sodium storage mechanism of the TSFC is proposed. [ABSTRACT FROM AUTHOR]

In this work, four shale cores with various mineral compositions were extracted from the Wufeng-Longmaxi formations in the Fuling area of Sichuan Basin to conduct a series of imbibition simulation experiments at normal temperature and pressure. Nuclear magnetic resonance monitoring technology was utilized to estimate the distribution positions of fracturing fluid at various imbibition times during the imbibition process. The molecular force was used to analyze the transport and storage mechanism of fracturing fluid in a shale reservoir. Due to clear differences in the distribution characteristics of fracturing fluid in shale samples with various mineral compositions, the T2 distribution of fractured shale sample imbibition demonstrated double-crests characteristics, the T2 of hard, brittle shale sample imbibition indicated a unimodal distribution, and the T2 of clay-rich shale sample imbibition revealed a trimodal distribution. The main pore radius of hard brittle shale reservoir in Wufeng-Longmaxi formations was 0.4-100 nm, and molecules and macropores were the primary channels for fracturing fluid migration. The fastest imbibition rate was reported 2 h prior to imbibition, and the imbibition amount of fracturing fluid amounted to about half of the total imbibition. The spontaneous imbibition of fracturing fluid was affected by three main forces, namely, (1) the dipoledipole force and hydrogen bond interaction (involved in entering inorganic micropores) between water molecules and the molecules on the inorganic pore wall; (2) the hydrogen bond interaction (involved in entering organic pores) between water molecules and the oxygen functional group on kerogen molecules; and (3) the capillary force (involved in entering molecules and macropores). [ABSTRACT FROM AUTHOR]

Aqueous zinc-ion battery (AZIB) attracts a great attention and becomes a hotspot due to its low cost and high safety in recent years. However, the sluggish transport kinetics of cathode materials is a significant drawback limiting their application. Herein, this work reports a novel VSe 2 /V 2 O 5 · n H 2 O/reduced graphene oxide ternary composite (VSe 2 /V 2 O 5 · n H 2 O/rGO) constructed with an anti-aggregation and porous 3D framework. The as-prepared ternary composite acting as cathode for AZIBs could provide a high capacity of 327.4 mA h g−1 at the current density of 0.2 A g−1. More importantly, it also possesses excellent rate capability and cyclic stability, which deliver a specific capacity of 254 mA h g−1 at a high current density of 5 A g−1. In addition, the structural evolution and transport kinetics of VSe 2 /V 2 O 5 · n H 2 O/rGO upon cycling are investigated. Benefiting from the high reversibility of phase evolution and the reduced graphene oxide (rGO) composition, the prepared VSe 2 /V 2 O 5 · n H 2 O/rGO can maintain a robust structure during cycling, improve the transport kinetics and thus displaying an outstanding electrochemical performance. This study offers a new route for designing cathode materials and promoting the development of high-performance AZIBs. • VSe 2 /V 2 O 5 · n H 2 O/rGO ternary composite was obtained by simple hydrothermal method. • The 3D framework design benefits structural stability and fast charge transfer. • Such ternary composite electrode shows enhanced rate capability. [ABSTRACT FROM AUTHOR]

Transition metal fluoride (TMF) conversion cathodes, with high energy density, are recognized as promising candidates for next-generation high-energy Li/Na-ion batteries (LIBs/SIBs). Unfortunately, the poor electronic conductivity and detrimental active material dissolution of TMFs seriously limit the performance of TMF-LIBs/SIBs. A variety of FeF3-based composites are designed to improve their electrochemical characteristics. However, the storage mechanism of the conversion-type cathode for Li+ and Na+ co-storage is still unclear. Here, the storage mechanism of honeycomb iron (III) fluoride and carbon (FeF3@C) as a general cathode for LIBs/SIBs is analyzed by kinetics. In addition, the FeF3@C cathode shows high electrochemical performance in a full-cell system. The results show that the honeycomb FeF3@C shows excellent long-term cycle stability in LIBs (208.3 mA h g−1 at 1.0 C after 100 cycles with a capacity retention of 98.1%). As a cathode of SIBs, the rate performance is unexpectedly stable. The kinetic analysis reveals that the FeF3@C cathode exhibit distinct ion-dependent charge storage mechanisms and exceptional long-durability cyclic performance in the storage of Li+/Na+, benefiting from the synergistic contribution of pseudocapacitive and reversible redox behavior. The work deepens the understanding of the conversion-type cathode in Li+/Na+ storage. [ABSTRACT FROM AUTHOR]

Aqueous ammonium-ion batteries (AAIBs) are promising candidates for next-generation energy storage devices. However, organic materials as suitable anodes face severe challenges due to their structural instability and poor conductivity, which hinder the development of AAIBs. Herein, an innovative approach is introduced by incorporating an organic benzoquinone framework, 5,7,11,14-tetraaza-6,13-pentacenequinone (TAPQ), with reduced graphene oxide (rGO) using a solvent exchange method. Benefiting from π-π interaction and electron delocalization, TAPQ/rGO features enhanced cycling stability and ion/electron transportation. Consequently, the composite electrode delivers a reversible capacity of 181.7 mAh g -1 at 0.5 A g -1 and achieves an ultrahigh capacity retention of 94.5% over 10 000 cycles at 5 A g -1 , surpassing most reported anodes in AAIBs. Combining density functional theory (DFT) calculation and ex situ electrochemical characterizations, the unique storage mechanism of chelation coordination between NH 4 + and N, O is revealed. Furthermore, a high-performance NH 4 + -based full cell, assembled with TAPQ/rGO anode and copper hexacyanoferrate (Cu-HCF) cathode, demonstrates long-term cycling stability with 93.95% capacity retention after 500 cycles. This work pioneers the concept of π-π interactions to significantly improve NH 4 + storage performance, presenting a novel strategy for the advancement of AAIBs research., (© 2024 Wiley‐VCH GmbH.)

K+ and Al3+ as the dual metal ions are uniformly pre-intercalated into the framework and the interlayer of δ-MnO 2 by hydrothermal method. The energy storage mechanism of δ-MnO 2 is the combination of dissolution/deposition and H+/Zn2+ co-insertion/co-extraction. [Display omitted] Layered δ-MnO 2 is a promising cathode material for aqueous zinc ion batteries (AZIBs) due to its high theoretical capacity, high operating voltage and low cost. However, the dissolution of MnO 2 and the disproportionation of Mn3+ will lead to irreversible reaction and serious structural degradation of the material during cycling process. In this work, the Al3+ pre-intercalated K 0.27 MnO 2 ·0.54H 2 O was prepared by a one-step hydrothermal method with citric acid as the complexing agent and weak reducing agent. Based on the pillars of bimetallic ions K+, Al3+ and water, the framework and interlayer of δ-MnO 2 is stabilized. Besides, a certain amount of Al3+ facilitates the increase of crystal water compared with the pure K 0.27 MnO 2 ·0.54H 2 O, which is not only conducive to promote the construction of porous and loose 3D morphology, but also beneficial to improve the stability of layered structure and accelerate the migration rate of zinc ions. Contributed to the dissolution/deposition reaction mechanism combined with H+/Zn2+ co-insertion/co-extraction mechanism, it has achieved the high capacity with the maximum reversible specific capacity of 269.5 mAh g−1 at 0.5 A g−1 and excellent stability with 205.8 mAh g−1 even after 300 cycles in Zn//Al-KMO battery. [ABSTRACT FROM AUTHOR]

Sodium‐ion batteries (SIBs) have gained tremendous attention for large‐scale energy storage applications due to the natural abundance, low cost, and even geographic distribution of sodium resources as well as a similar working mechanism to lithium‐ion batteries (LIBs). One of the critical bottlenecks, however, is the design of high‐performance and low‐cost anode materials. Graphite anode that has dominated the market share of LIBs does not properly intercalate sodium ions. However, other carbonaceous materials are still considered as one of the most promising anode materials for SIBs in virtue of their high electronic conductivity, abundant active sites, hierarchical porosity, and excellent mechanical stability. In this review, we have tried to summarize the latest progresses made on the development of carbon‐based negative electrodes (including hard carbons, soft carbons, and synthetic carbon allotropes) for SIBs. We also have provided a comprehensive understanding of their physical properties, the sodium ions storage mechanisms, and the improvement measures to cope with the current challenges. In addition, we have proposed future research directions for SIBs that will provide important insights into further development of carbon‐based materials for SIBs. [ABSTRACT FROM AUTHOR]

Among many energy storage equipment, aqueous zinc-ion batteries (AZIBs) have attracted much attention because of their high safety and low cost. Herein, orthorhombic V2O5 nanobelts (NBs-V2O5) are prepared, and it is compounded with carbon nanotubes (CNTs), achieving freestanding NBs-V2O5/CNTs composite films. When NBs-V2O5/CNTs cathode is used for AZIBs, the assembled batteries provide excellent rate capability, large capacity of 380 mAh g−1 at 0.2 A g−1, and high capacity retention rate of 95% after 1000 cycles at the current density of 5 A g−1. Besides, due to the outstanding conductivity and flexibility of the NBs-V2O5/CNTs composite films, soft-package batteries are assembled with steady electrochemical performance at various bending states. The NBs-V2O5/CNTs cathode exhibits a Zn2+/H+ insertion/extraction storage mechanism during charge/discharge processes by in situ Raman spectroscopy investigations, leading to fast kinetics of ion transfer. [ABSTRACT FROM AUTHOR]

Carbon-based electrodes of potassium-ion batteries are of great research interest ascribed to their low cost and environmentally friendly distinctions. However, traditional carbon materials usually exhibit weak mechanical properties and incomplete crosslinking, resulting in poor stability and electrochemical performance. Herein, we report a new strategy for modifying reduced graphene oxide into a uniform few-layer structure through a sol—gel method combined with acid etching treatment. The obtained chemical cross-linking and mechanically reinforced carbon network constructed by graphene (CNCG) demonstrates excellent electrochemical and mechanical properties. Adopted as a free-standing anode (∼ 7 mg·cm−2) for potassium ion battery, the as-achieved CNCG delivers a high reversible specific capacity of 317.7 mAh·g−1 at a current density of 50 mA·g−1 and admirable cycle stability (208.4 mAh·g−1 at 50 mA·g−1 after 500 cycles). The highly reversible structural stability and fully cross-linked properties during potassiation are revealed by ex-situ characterization. This work provides new ideas for the synthesis of new carbon materials and the development of high-performance electrodes. [ABSTRACT FROM AUTHOR]

Abstract Potassium‐ion batteries (PIBs) show great potential in the application of large‐scale energy storage devices due to the comparable high operating voltage with lithium‐ion batteries and lower cost. Carbon‐based materials are promising candidates as anodes for PIBs, for their low cost, high abundance, nontoxicity, environmental benignity, and sustainability. In this review, we will first discuss the potassium storage mechanisms of graphitic and defective carbon materials and carbon‐based composites with various compositions and microstructures to comprehensively understand the potassium storage behavior. Then, several strategies based on heteroatoms doping, unique nanostructure design, and introduction of the conductive matrix to form composites are proposed to optimize the carbon‐based materials and achieve high performance for PIBs. Finally, we conclude the existing challenges and perspectives for further development of carbon‐based materials, which is believed to promote the practical application of PIBs in the future.

• Introduced the anode, cathode materials, and lithium storage mechanism of LICs. • Conducted a comprehensive review of TMO research for LIC anodes. • Highlighted advanced characterization techniques for LIC anodes. • Provided an outlook on the development prospects, opportunities, and challenges of TMOs in LICs. In recent years, driven by the widespread adoption of hybrid electric vehicles and portable electronic devices, there has been a notable surge in demand for energy storage devices boasting high power density and energy density. Additionally, the growing emphasis on renewable energy sources has spurred an immediate need for high energy density storage solutions. Lithium-ion capacitors (LICs) represent a novel class of energy storage devices positioned between supercapacitors and lithium-ion batteries. Leveraging their high power density, high energy density, and extended cycle life, LICs are poised to meet the burgeoning demand for advanced energy storage technologies. Transition metal oxide (TMO) materials boast exceptional lithium storage capacity, a moderate voltage platform, abundant resources, affordability, eco-friendliness, making them ideal candidates as anode electrode materials for LICs. This review explores the various preparation methods employed for transition metal oxide anodes, delving into their electrochemical properties and conducting a thorough analysis of their advantages and drawbacks as anode materials for LICs. Furthermore, the review offers insights into the prospective future directions for the development of transition metal oxide anodes, guiding research efforts toward enhancing the performance and applicability of TMO-based LICs. [ABSTRACT FROM AUTHOR]

[Display omitted] • Novel eco-friendly method to upgrade waste plastic into valuable carbon materials. • Enhanced electrochemical performance through molecular design, doping, and structure regulation. • Clarifies the sodium storage mechanism in hard carbons by linking synthesis, structure, and performance. The development of high-performance hard-carbon (HC) anode materials for sodium-ion batteries was constrained by slow charge-transfer kinetics and sodium-storage mechanisms. In this paper, high nitrogen-doped (12.24 %) HC with an efficient interworking structure was synthesized in situ using waste plastics as precursors by utilizing the strong 2-D self-template effect of guanine. Elucidating the mechanism of sodium storage in heteroatom-doped carbon with coexisting heterocyclic and graphitic nitrogen, which synergistically enhances electrochemical activity, utilizing a range of in-situ and ex-situ characterization methods. Based on density functional theory (DFT), it has been discovered that the doping of pyrrole nitrogen (N5) and pyridinium nitrogen (N6) can effectively expand the interlayer spacing during the Na+ sodiated/de-sodiated process, thereby enhancing electrochemical activity. The optimized HC has increased the Na+ diffusion coefficient by 1.5 orders of magnitude (10-8.2 cm2 s−1 vs 10-9.76 cm2 s−1) and exhibits high reversible capacity (452 mAh/g@20 mA g−1), high rate performance (388mAh/g@500 mA g−1), superior cycling stability (87.6 % @500 mA g−1 after 2,000 cycles). The full cell exhibits good cyclic stability (91.87 %@100 mA g−1 after 2,00 cycles), while the designed pouch cell also demonstrates favorable cycle life (90.78 %@200 mA g−1 after 100 cycles). [ABSTRACT FROM AUTHOR]

[Display omitted] • N-doped mesoporous hollow hard carbon nanospheres (NMHS) show high structure stability. • NMHS exhibit an excellent capacity retention of 92 % at 2 A g−1 over 5000 cycles. • The assembled dual-ion capacitors obtain both high energy density and power density. • The mechanism of anions storage on hard carbon and the different N-species effect are provided. High structural strength in-situ N-doped mesoporous hollow hard carbon nanospheres (NMHS) is prepared to overcome the low anions storage capacity (93 mAh g−1) of easy exfoliated graphite for dual-ion capacitors (DICs). The rich mesoporous structure facilitates the anions diffusion, and the hollow cavity provides expansion space in storage and weakens the high diffusion resistance in the nuclear bulge. With the synergistic effect, The NMHS delivers a high reversible capacity of 100 mAh g−1 with a low decay of 8 % over 5000 cycles at 2 A g−1. In-situ Raman reveals the storage mechanism on hard carbon is "adsorption (major)-intercalation (minor)". DFT calculations decode the effective storage action of graphitic N and pyridinic N. Consequently, the assembled NMHS-DICs exhibit good long-cycle performance and heterotherm stability, providing a high energy/power density of 200 Wh kg−1 and 11858 W kg−1. This work verifies a feasible cathode design strategy with future application potential on DICs. [ABSTRACT FROM AUTHOR]

[Display omitted] • The sandwich-like porous carbon was designed and prepared by durian peels. • A ZIHSs charge storage mechanism of DrHPC was firstly investigated. • For ZIHSs, DrHPC-4 exhibited an excellent energy density of 164 Wh kg−1. • Impressive specific capacitance and ultra-long life have been attained. Porous carbon materials derived from biomass are widely used as cathodes in Zinc-ion hybrid supercapacitors (ZIHSs) due to their inherent properties. However, understanding the link between biomass structure, composition, and electrochemical performance remains challenging. This study synthesized sandwich-like porous carbon materials (DrHPC) from durian peels. DrHPC features a unique sandwich-like structure characterized by abundant micropores, high specific surface area, elevated oxygen content, and minimal nitrogen content. These characteristics facilitate Zn2+ transport, provide active sites, enhance adsorption capacity, and improve kinetics. The aqueous Zn//DrHPC ZIHSs show significant specific capacity (232 mA h g−1 at 0.1 A/g), excellent rate capability (106 mA h g−1 at 10 A/g), high energy density (164 Wh kg−1 at 33 W kg−1), and long cycle life (96 % capacitance retention after 12,000 cycles at 10 A/g). Mechanistic studies reveal Zn2+ adsorption primarily on C O/N Ox functional groups, enhancing pseudocapacitance. This research provides insights for designing advanced biomass-derived carbon materials for improved ZIHSs. [ABSTRACT FROM AUTHOR]

Aqueous ammonium‐ion (NH4+) batteries (AAIB) are a recently emerging technology that utilize the abundant electrode resources and the fast diffusion kinetics of NH4+ to deliver an excellent rate performance at a low cost. Although significant progress has been made on AAIBs, the technology is still limited by various challenges. In this Minireview, the most recent advances are comprehensively summarized and discussed, including cathode and anode materials as well as the electrolytes. Finally, a perspective on possible solutions for the current limitations of AAIBs is provided. [ABSTRACT FROM AUTHOR]

In situ (operando) electrochemical dilatometry (ECD) provides information on the expansion/shrinkage of an electrode during cell cycling. It is shown that the ECD signal can be used as descriptor to characterize the charge storage behavior of lithium and sodium ions in hard carbon electrodes. It is found that sodium storage in hard carbons occurs by a three‐step mechanism, namely I) insertion, II) pore filling, and III) plating. Step III can be seen from a sudden increase in electrode thickness for potentials below around 36 mV versus Na+/Na and is assigned to plating on the hard carbon surface. Interestingly, this last step is absent in the case of lithium which demonstrates that the storage behavior between both alkali metals is different. The plating mechanism is also supported by reference experiments in which bulk plating is enforced. Bulk plating on hard carbon electrodes can be detected more easily for sodium compared to lithium. It is also found that the type of binder strongly influences the dilatometry results. A comparison between the binders sodium salt of carboxymethyl cellulose and poly(vinylidene difluoride) shows that the use of the former leads to notably smaller first electrode expansion as well as a higher initial Coulomb efficiency. [ABSTRACT FROM AUTHOR]

Hard carbons (HCs) have great potential as anode material for high‐performance potassium ion batteries (PIBs). However, due to the complexity of HCs, the relationship between their structures and potassium (K) storage behaviors is still not quite clear. Here, three types of HCs with different structures are designed for further understanding the electrochemical storage processes. Among them, the carbon spheres (CS) exhibit impressive rate performance (161.6 mAh g−1 at 2 A g−1) and cycle stability (140.2 mAh g−1 at 2 A g−1 after 500 cycles). The superior performance of CS can be mainly ascribed to the intercalation into its locally‐ordered carbon nanocrystallites, and the charge/discharge processes are further characterized with significant pseudocapacitive dominating. Suitable nanocrystalline size and the ratio of defects with proper morphology are the key factors to improve K storage efficiency. This work will contribute to understanding the role of these factors in the K storage performance of carbon materials. [ABSTRACT FROM AUTHOR]

88 Halim, J.; Palisaitis, J.; Lu, J.; Thörnberg, J.; Moon, E.; Precner, M.; Eklund, P.; Persson, P. Å.; Barsoum, M.; Rosen, J. Synthesis of two-dimensional Nb1. Keywords: battery; electrode materials; storage mechanism; supercapacitors EN battery electrode materials storage mechanism supercapacitors 53 88 36 03/11/22 20220301 NES 220301 Introduction It is worth emphasizing that the predictable exhaustion of fossil fuel resources and its negative environmental impacts have led to requests for evolving and improving renewable and eco-friendly energy resources to provide energy on demand to the world ([41]; [42]; [45]; [56]; [86]; [122]; [126]; [176]; [206]). 283 Yang, J.; Naguib, M.; Ghidiu, M.; Pan, L. M.; Gu, J.; Nanda, J.; Halim, J.; Gogotsi, Y.; Barsoum, M. W. Two-dimensional Nb-based M4C3 solid solutions (MXenes). On the other hand, because of its higher operating voltage windows of Organic electrolyte and IL-based SCs usually varying between 2.5-2.8 V and 3.5-4 V, respectively, both organic electrolyte-based SCs and IL-based SCs dominate the markets at present ([120]; [183]; [187]; [211]; [305]). 105 Huang, Y.; Zhao, Y.; Bao, J.; Lian, J.; Cheng, M.; Li, H. Lawn-like FeCo2S4 hollow nanoneedle arrays on flexible carbon nanofiber film as binder-free electrodes for high-performance asymmetric pseudocapacitors. [Extracted from the article]

Abstract Amorphous carbon shows great potential as an anode material for high-performance potassium-ion batteries; however, its abundant defects or micropores generally capture K ions, thus resulting in high irreversible capacity with low initial Coulombic efficiency (ICE) and limited practical application. Herein, pore engineering via a facile self-etching strategy is applied to achieve mesoporous carbon (meso-C) nanowires with interconnected framework. Abundant and evenly distributed mesopores could provide short K+ pathways for its rapid diffusion. Compared to microporous carbon with highly disordered structure, the meso-C with Zn-catalyzed short-range ordered structure enables more K+ to reversibly intercalate into the graphitic layers. Consequently, the meso-C shows an increased capacity by ~ 100 mAh g−1 at 0.1 A g−1, and the capacity retention is 70.7% after 1000 cycles at 1 A g−1. Multiple in/ex situ characterizations reveal the reversible structural changes during the charging/discharging process. Particularly, benefiting from the mesoporous structure with reduced specific surface area by 31.5 times and less defects, the meso-C generates less irreversible capacity with high ICE up to 76.7%, one of the best reported values so far. This work provides a new perspective that mesopores engineering can effectively accelerate K+ diffusion and enhance K+ adsorption/intercalation storage.

Abstract Ti3C2T x , a novel two-dimensional layer material, is widely used as electrode materials of supercapacitor due to its good metal conductivity, redox reaction active surface, and so on. However, there are many challenges to be addressed which impede Ti3C2T x obtaining the ideal specific capacitance, such as restacking, re-crushing, and oxidation of titanium. Recently, many advances have been proposed to enhance capacitance performance of Ti3C2T x . In this review, recent strategies for improving specific capacitance are summarized and compared, for example, film formation, surface modification, and composite method. Furthermore, in order to comprehend the mechanism of those efforts, this review analyzes the energy storage performance in different electrolytes and influencing factors. This review is expected to predict redouble research direction of Ti3C2T x materials in supercapacitors.

Sodium ion batteries (SIBs) are promising candidates for large‐scale energy storage owing to the abundant sodium resources and low cost. The larger Na+ radius (compared to Li+) usually leads to sluggish reaction kinetics and huge volume expansion. One of the efficient strategies is to reduce the size of electrode materials or the components of electrolytes to a suitable scale where size effect begin to emerge, leading to the improved or varied thermodynamics, kinetics, and mechanisms of sodium storage. However, only a few systematic reviews address size effects in SIBs, which requires further attention urgently. Herein, after a brief discussion of the general size effect, the size‐related kinetics, thermodynamics (equilibrium voltage and morphology), and sodium storage mechanisms (phase transition, conversion reaction, interfacial, and nanopore storage) of electrode materials are presented. The size effect on liquid, polymer, and inorganic solid‐state electrolytes are discussed as well, including the size of solvent molecules, Na salts, and inorganic fillers. Finally, neutral and adverse size effects are discussed, and some useful strategies are proposed to overcome them. The deep insights into the size effect will provide instructive guidelines for developing SIBs and other new energy storage systems. [ABSTRACT FROM AUTHOR]

SnSe nanorods with a length of about 1–2 μm and a width of 100 nm are achieved with the assistance of a metal complex. The growth mechanism and how metal complexes influence the morphology of SnSe are investigated. As a lithium-ion-battery (LIB) anode, the nanorod structure of SnSe not only provides a fast electron/ion transmission path but also relieves the volume expansion because of the inherent mechanical strength of the one-dimensional structure. The phase change of SnSe is evaluated by ex situ X-ray diffraction during lithium insertion/extraction to study the lithium-ion storage mechanism. Compared with SnSe nanoparticles, SnSe nanorods exhibit a better electrochemical performance, delivering an initial reversible specific capacity of 683.6 mAh g–1 at 100 mA g–1 and maintaining a specific capacity of 302 mAh g–1 even after 100 cycles, which demonstrates a promising anode material for LIBs. [ABSTRACT FROM AUTHOR]

Sodium ion batteries (SIBs) have been extensively investigated as a promising alternative for lithium ion batteries (LIBs) owing to the readily available character of sodium, lower costs of battery systems, as well as a similar working mechanism to LIBs. However, this view turns out to be oversimplified; countless reviews especially in the last years contradict each other, and it is still a challenging task to design highly performing electrode materials for SIBs. Due to the larger radius of Na+, its lower covalent character, and the resulting changes in intercalation chemistry, sodium is far from being only the bigger relative of lithium, and the difference leads to altered loading curves, and the occurrence of a multiplicity of binding sites. An in‐depth holistic understanding of the sodium storage mechanisms is needed to resolve the controversial discussions in the research community, ideally starting with unquestionable thermodynamic points. Here, taking a tutorial perspective, first the recent discussions on the storage mechanism of sodium in carbons are reviewed from an unorthodox viewpoint, namely addressing sodium uptake as a multifaceted adsorption process with an added electrochemical binding potential. This model is based on literature data. Afterward, challenges and perspectives revealed by such a model are discussed. [ABSTRACT FROM AUTHOR]