Theoretical Specific Capacity Research Articles

Synergistic effect of molybdenum dioxide wrapped nitrogen doped carbon nanotubes in binder-free anodes for enhanced lithium storage properties

Molybdenum dioxide (MoO2) is regarded as a potential anode for lithium-ion batteries due to its highly theoretical specific capacity. However, its further application in lithium-ion battery is largely limited by insufficient practical discharge capacity and cyclic performance. Here, MoO2nanoparticles are in-situ grown on three-dimensional nitrogen doped carbon nanotubes (NCNTs) on nickel foam substrate homogeneously using a simple electro-deposition method. The unique structural features are favorable for lithium ions insertion and extraction and charge transfer dynamics at electrode/electrolyte interface. As a proof of concept, the as-synthesized nanocomposites have been employed as anode for lithium-ion battery, exhibiting a reversible and significantly improved discharge capacity of ∼517 mA h g-1at the current density of 150 mA g-1as well as superior cycle and rate performance. The first-principle calculations based on density functional theory and electrochemical impedance spectroscopy results demonstrate a reduced energy barrier of lithium ions diffusion, improved lithium storage behavior, reduced structure collapse, and significantly enhanced charge transfer kinetics in MoO2/NCNTs nanocomposites with respect to MoO2powder. The excellent performance makes as-prepared MoO2/NCNTs nanocomposites promising binder-free anode for high performance lithium-ion batteries. This work also provides important theoretical insights for other state-of-the-art batteries design.

A Novel Anion Receptor Additive for −40 °C Sodium Metal Batteries by Anion/Cation Solvation Engineering

AbstractSodium metal batteries, known for their high theoretical specific capacity, abundant reserves, and promising low‐temperature performance, have garnered significant attention. However, the large ionic radius of Na+ and sluggish transport kinetics across the interfacial structure hinder their practical application. Previous reviews have rarely regulated electrolyte performance from the perspective of anions, as important components of the electrolyte, the regulation mechanism is not well understood. Herein, a novel anion receptor additive, 4‐aminophenylboronic acid pinacol ester (ABAPE), is proposed to weaken the coupling between anions and cations and accelerate Na+ transport kinetics. The results of theoretical calculations and X‐ray photoelectron spectroscopy with deep Ar‐ion etching demonstrate that the introduction of this additive alters the solvation structure of Na+, reduces the desolvation barrier and forms a stable and dense electrode‐electrolyte interface. Moreover, ABAPE forms hydrogen bonds (−NH ⋅ ⋅ ⋅ O/F) with H2O/HF, effectively preventing the hydrolysis of NaPF6 and stabilizing acidic species. Consequently, the Na||Na symmetric cell exhibits excellent long‐cycle performance of 500 h at 1 mA cm−2 and 0.5 mAh cm−2. The Na||Na3V2(PO4)3 (NVP) cell with the addition of ABAPE maintains a capacity retention of 84.29 % at 1 C after 1200 cycles and presents no capacity decay over 150 cycles at −40 °C.

Accelerated Ion-Electron Transport in Bi-Heterostructures Constructed Based on Ohmic Contacts for Efficient Bi-Directional Catalysis of Lithium-Sulfur Batteries.

Although lithium-sulfur batteries have satisfactory theoretical specific capacity and energy density, they are difficult to further commercialize due to the shuttle effect of soluble polysulfides and slow sulfur oxidation kinetics. Based on this, in this work, the catalyst MXene-VS4-SnS2 (MVS), a dual heterostructured catalyst with ohmic contacts, is prepared by a one-step hydrothermal method and electrostatic self-adsorption for lithium-sulfur battery cathode materials. Experimental and theoretical results show that the ohmic contact induces spontaneous charge rearrangement, resulting in the formation of a fast charge transfer pathway at the MVS heterojunction interface, which helps to reduce the energy barrier for polysulfide reduction and Li2S oxidation during the discharge/charge process. In addition, the inherent sulfophilicity of VS4 and SnS2 promotes the conversion of S species, while the pleated MXene nanosheets not only provide a highly conductive network for the active sulfur but also retain a rich internal space to maintain the integrity of the cathode structure during the continuous cycling process. As a result, the MVS cathode exhibits excellent electrochemical performance even under high sulfur loading. The integration of excellent performance with a facile synthesis process provides a promising approach for designing highly efficient electrocatalysts suitable for the energy field.

Understanding of a Ni-Rich O3-Layered Cathode for Sodium-Ion Batteries: Synthesis Mechanism and Al-Gradient Doping.

O3-type NaNi0.8Mn0.1Co0.1O2 (NaNMC811) cathode active materials for sodium-ion batteries (SIBs), with a theoretical high specific capacity (∼187mAhg-1), are in the preliminary exploration stage. This study comprehensively investigates NaNMC811 from multiple perspectives. For the first time, the phase evolution ( - - ) during the solid-state synthesis is systemically investigated, which elucidates in-depth the mechanisms of the thermal sodiation process. Furthermore, an Al-gradient doping of NaNMC811 wassuccessfully implemented through Al2O3 coating on the cathode active material (CAM) precursor. The modified Al-NaNi0.8Mn0.1Co0.1O2 (Al-NaNMC811) exhibits excellent electrochemical dynamics and performance, maintaining a specific capacity above 100mAhg-1 after 100 cycles at 0.1 C (1.5-4.1 V) while providing a promising capacity retention of 63%. Additionally, the material demonstrates excellent rate capabilities, retaining a specific capacity of 107 mAh g-1 at 5 C. Compared to pristine NaNMC811, the modified Al-NaNMC811 is proven to have improved electrochemical kinetics with a higher Na+ diffusion coefficient due to dilated (003) interplanar spacing, and a more stable structure during the electrochemical charge-discharge processes, which is attributed to stronger Al-O bond energy. Understanding phase formations during the synthesis and comprehensive insight in the gradient doping for O3-type NaNMC811 CAMs guides further development of next-generation SIBsmaterials.

Design, perspectives, and challenges of modification strategies for alkali metal anodes

Abstract. The alkali metal anode has emerged as a focal point of research due to its extremely low oxidation-reduction potential and high theoretical specific capacity. However, challenges such as unstable solid electrolyte interphase (SEI), infinite volume expansion, and uncontrollable dendrite growth result in low coulombic efficiency and irreversible losses during the deposition and stripping processes. To address these issues, various effective strategies have been proposed to protect the alkali metal anode and achieve dendrite-free growth. In this review, we summarize recent advancements in enhancement strategies for alkali metal anodes, including the construction of three-dimensional current collectors and interface engineering. Specifically, we delve into the development of carbon-based current collectors with various dimensions and structures and the application of interface engineering techniques to tackle the challenges of unstable SEI, volume changes, and dendrite growth. Furthermore, we explore advanced characterization techniques that provide deeper insights into the reaction mechanisms and behavior of these enhancement strategies. Finally, we discuss the current limitations and future research directions in protecting alkali metal anodes, aiming to provide valuable insights into the study of dendrite growth and the development of effective protection strategies for alkali metal anodes.

One-Step Synthesis of NiCo-LDH@Ni(OH)2 Heterostructure Foams on Biomass-Derived Porous Carbon for High-Performance Supercapacitors.

Layered double hydroxides (LDHs) have attracted much attention as pseudocapacitor supercapacitor electrodes because of their high theoretical specific capacity. However, LDHs have drawbacks such as poor electrical conductivity, and their specific capacities are lower than the theoretical values. In this work, NNCLDH@OPC electrodes are constructed via in situ synthesis of heterostructure foams (NNCLDH) consisting of NiCo-LDH and Ni(OH)2 on pomelo peel-derived porous carbon (OPC) through a one-step solvothermal method using ZIF-67 as a template. Owing to the synergistic effect of the 3D nanofoam structure and the multicomponent heterostructure as well as the conductive porous carbon support, the NNCLDH/OPC exhibited ultrahigh electrochemical performance as well as excellent cycling stability: a specific capacity of 3290 F g-1 at 1 A g-1 and a capacitance retention of 77.8% after 4000 cycles at a current density of 10 A g-1. In addition, the assembled NNCLDH@OPC//OPC asymmetric supercapacitor (ASC) has a maximum energy density of 51Wh kg-1 with a power density of 812W kg-1 and a maximum power density of 16kW kg-1 at a current density of 20 A g-1. These results demonstrate the significant application potential of NNCLDH/OPC composites in supercapacitor electrodes.

Innovations in Energy Through Nanomaterials Enhancing Solid-State Battery Safety and Efficacy

This paper explores the potential of Si-based nanomaterials to enhance the performance of lithium-ion batteries (LIBs), particularly for electric vehicles (EVs). Traditional graphite anodes limit the energy density and range of EVs, increasing the need to search for alternative materials like silicon, which offers a much higher theoretical specific capacity. However, silicon’s application has been challenged by significant volume changes during cycling, leading to mechanical stress and failure. The use of nanotechnology, especially silicon nanomaterials, offers promising solutions to these challenges. Silicon nanostructures, such as nanowires, exhibit enhanced mechanical properties, allowing them to withstand volumetric changes and maintain high capacity during cycling. This review delves into the chemo-physical properties of silicon, the challenges posed by silicon anodes (SAs), and the recent advancements in silicon nanomaterials. Additionally, it also discusses different approaches to enhancing the performance of Si-based anodes, as well as the difficulties that exist now and the directions that future research in this exciting area is headed.

Application of nanotechnology in the negative electrode of Si-based lithium-ion batteries

Modern electronics and electric cars frequently employ lithium-ion batteries (LIBs) because of their excellent energy density, safety, and environmental friendliness. The anode of LIBs is typically composed of carbon. Nevertheless, it loses a lot of energy when charging and draining. Lithium metal precipitates quickly from the surface of carbon electrodes and forms dendrites. These can pass through the diaphragm and cause short circuits inside the battery, posing a public safety risk. The advantages of the silicon-based anode are excellent safety, low operating voltage, and high theoretical specific capacity. It is among the most critical potential materials for high-energy-density lithium-ion batteries. However, its drawbacks, such as volume expansion and poor electrical conductivity, limit the development of LIBs. In recent years, the emergence of nanotechnology has well solved these problems. This paper first explains how silicon-based lithium-ion batteries work and summarizes the challenges of silicon-based anodes. Then, it explores the application of nanotechnology in silicon-based anode, including different dimensions of silicon nanomaterials. After the group, the paper analyzes the shortcomings of current research and proposes future directions.

Design of Silicon-Based Anode Materials for High Energy Density Li-Ion Batteries

Compared to other types of batteries, lithium batteries have an extremely high energy density, which means they can store more energy while maintaining a smaller size and weight. The ideal electrode material must have a high lithium ion capacity to store many lithium ions. In addition, the electrode material must have good electronic conductivity to promote lithium ions' rapid entry and exit. However, traditional carbon materials have limited theoretical specific capacity, and the transmission of lithium-ion batteries in traditional materials is limited, resulting in a significant decrease in capacity. Silicon has a theoretical capacity of up to 4200mAh/g, more than ten times the capacity of commercial graphite negative electrodes. In addition, silicon and lithium can undergo alloying reactions to form Li Si alloys, which helps improve the material's specific capacity. This article first summarizes the advantages of electric vehicles and lithium-ion batteries. Then, the benefits and challenges of using silicon-based materials as negative electrodes for lithium-ion batteries were elaborated in detail, and finally, the prospects of silicon-based materials in lithium-ion battery applications were summarized. This article has reference significance in improving the energy density of lithium-ion batteries.

Highly Effective Polyacrylonitrile-Rich Artificial Solid-Electrolyte-Interphase for Dendrite-Free Li-Metal/Solid-State Battery.

Lithium metal anode batteries have attracted significant attention as a promising energy storage technology, offering a high theoretical specific capacity and a low electrochemical potential. Utilizing lithium metal as the anode material can substantially increase energy density compared with conventional lithium-ion batteries. However, the practical application of lithium metal anodes has encountered notable challenges, primarily due to the formation of dendritic structures during cycling. These dendrites pose safety risks and degrade battery performance. Addressing these challenges necessitates the development of a reliable and effective protection layer for lithium metal. This study presents a cost-effective and convenient method to spontaneously produce lithium metal protective layers by creating polymeric layers by using acrylonitrile (AN). This method remarkably extends 6× of the lifetime of lithium metal anodes under high current density (1 mA/cm2) cycling conditions. While the cycle life of bare lithium metal is approximately 150 h under high current cycling conditions, AN-treated lithium metal anodes exhibit an impressive longevity of over 900 h. The AN-treated lithium metal anodes are further integrated and tested with sulfide-based Li10GeP2S12 (LGPS) solid-state electrolytes to evaluate its interfacial stability at a solid-solid interface. The formation of the polyacrylonitrile (PAN)-rich ASEI, due to AN-treatment, effectively reduces and stabilizes the cell overpotential to only one-tenth of that with the interface without treatment. This strategy paves a route to enable a highly efficient and highly stable Li/LGPS solid-state battery interface.

First-principles calculation of ZrS2 as anode material of aluminium ion battery

Developing low-cost, high-stability, and high-performance new ion battery anode materials is beneficial for the rapid development of ion batteries in fields such as rail transit, electronic products, and aerospace. In this work, the first-principles calculation method was used to study the feasibility of ZrS2 monolayer as an anode material for Al ion batteries. The Al ions adsorbed in the strain system tend to bind to the ZrS2 monolayer. In the adsorption system, the adsorption of Al increases the conductivity of the system. The theoretical specific capacity of Al under full load is 690.303 mAh/g. The average open circuit voltage (OCV) is calculated to be 0.635 V. The diffusion barrier of Al ions is 0.071 eV. ZrS2 monolayer is an attractive anode material for ion batteries.

A Minireview of Multimetallic Iron‐Based Oxides for Supercapacitive Negative Electrode Materials

The serious mismatch between the positive and negative electrodes of supercapacitors (SCs) makes it imperative to develop high‐performance negative electrode materials. Among them, multimetallic iron‐based oxides (MIBOs) are intensively investigated attributed to their high theoretical specific capacitance, wide operating potential window, copious electrochemical active sites, variable metal oxidation states, and abundant redox centers. This paper briefly introduces some essential information on SCs and the most common synthesis methods of MIBOs. Also, the research progress of several important MIBOs and their composites is discussed. Finally, the existing problems and challenges of MIBOs are summarized and future outlooks are likewise proposed.

“Dead Lithium” Formation and Mitigation Strategies in Anode‐Free Li‐Metal Batteries

AbstractThin lithium‐metal foil is a promising anode material for next‐generation batteries due to its high theoretical specific capacity and low negative potential. However, safety issues linked to dendrite growth, low‐capacity retention, and short cycle life pose significant challenges. Also, it has excess energy that must be minimized in order to reduce the battery costs. To limit excess lithium, practical lithium metal batteries need a negative‐to‐positive electrode ratio as close to 1 : 1 as possible, which can be achieved through limiting excess lithium or using an “anode‐free” metal battery design. However, both designs experience fast capacity fade due to the irreversible loss of active lithium in the cell, caused by the formation of the solid electrolyte interphase (SEI), dendrite formation and “dead lithium,” – refers to lithium that has lost its electronic connection to the anode electrode or current collector. The presence of dead lithium in batteries negatively affects their capacity and lifespan, while also raising internal resistance and generating heat. Additionally, dead lithium encourages the growth of lithium dendrites, which poses significant safety hazards. Within this fundamental review, we thoroughly address the phenomenon of dead lithium formation, assessing its origins, implications on battery performance, and possible strategies for mitigation. The transition towards environmentally friendly and high‐performance metal batteries could be accelerated by effectively tackling the challenge posed by dead lithium.

High-entropy doping for high-voltage LiCoO2 with enhanced electrochemical performances

Lithium cobalt oxide (LiCoO2), as a pioneering layered oxide cathode material for lithium-ion batteries (LIBs), possesses exceptional theoretical specific capacity and cycling stability, positioning it as a leading candidate for commercial LIB applications. Boosting the upper-limit of charge voltage of LiCoO2 is a promising strategy to increase the capacity of batteries, vital for advancing energy storage solutions from portable electronics to electric vehicles. Nevertheless, hybrid redox reactions at high voltages speed up oxygen evolution, electrolyte decomposition, and irreversible phase transitions, ultimately causing rapid capacity fading.To address these challenges, we present a novel approach to enhance the structural stability and electrochemical performances of LiCoO2 cathode via La-Al-Mg-Y high-entropy doping. This strategy significantly improves the high-voltage cycling stability of the cathode material by retaining 72.5 % of its initial capacity after 500 cycles at 5 C under 4.6 V. Furthermore, the structural change caused by the phase transition between the O3 and H1-3 phases is remarkably suppressed. This advancement in LIB cathode technology paves the way for the development of high performance batteries and it is crucial for meeting the growing demand for sustainable energy storage.

Pre-lithiation synergized with magnesiothermic reduction to enhance the performance of SiO anode for Advanced lithium-ion batteries

Due to its high theoretical specific capacity, micron-sized silicon monoxide (SiO) is regarded as one of the most competitive anode materials for lithium-ion batteries with high specific energy density. However, originating from the low initial Coulombic efficiency (ICE) and large volume expansion, its large-scale application is seriously hindered. Herein, an easy-to-implement solid-state pre-lithiation method synergized with the magnesiothermic reduction process was performed to enhance the ICE of SiO and a common bimetallic hydride was used as a prelithiation reagent. Moreover, the effects of different pre-lithiation reagent amounts on the physical and electrochemical properties of SiOx are investigated. Notably, the SiOx-LA@C composite anchored by in-situ generated LiAl(SiO3)2 shows a more stable microstructure and excellent electrochemical properties, which delivers an ultrahigh ICE of 89.4 % and an excellent initial capacity of 1864.4 mAh g−1. Furthermore, the full cells were successfully assembled by using the prepared anodes, which exhibit relatively stable cycle performance over 150 cycles. This work suggests a safe and feasible route to enhance the ICE of SiOx for the applicable SiO-based anode materials.

Cu-doped graphene Cu/N2OG: A high-performance alkaline metal ion battery anode with record-theoretical capacity

Anode materials are paramount in dictating the performance of ion batteries. Therefore, the judicious design of novel anode materials boasting superior capacity is crucial to further enhancing the energy density of ion batteries. This study employs first-principles computational methods to systematically investigate the performance of Cu-doped graphene 2D material (Cu/N2OG) as an Li-ion batteries (LIBs), Na-ion batteries (NIBs), or K-ion batteries (KIBs) anode. Simulation results indicate that the structural asymmetry introduced by Cu doping significantly increases the active sites of the material, enhancing its theoretical specific capacity for Li/Na/K. Notably, the sodium storage theoretical capacity of Cu/N2OG reaches an impressive 3303.7 mAh/g, surpassing the capacity of all currently employed NIBs anode materials. Furthermore, Cu/N2OG also boasts high theoretical capacities, yielding capacities of 1651.8 mAh/g for LIBs and 1263.2 mAh/g for KIBs, respectively. The material retains excellent conductivity both prior to and following the adsorption of Li, Na, and K. Furthermore, Cu/N2OG demonstrates a low diffusion barrier and minimal lattice changes (<1 %), suggesting its potential as a high-performance anode for LIBs/NIBs/KIBs.

Carbonaceous C@FeS Flow Electrode for Electrochemcal Capacitive Deionization Application

FeS has attracted much attention in the field of capacitive deionisation of flow electrodes due to its high theoretical specific capacity and wide range of sources. However, it usually exhibits frustrating performance due to its inherent low conductivity and volume expansion during charging and discharging. Herein, we successfully prepared calcium alginate-coated FeS carbon spheres (C@FeS) with a hollow nanosphere structure by a combination of sol-gel and solid-phase sintering using sodium alginate as a carbon source. This unique hollow structure provides enough space for the expansion of FeS and enhances the stability of the sulfide; meanwhile, the internal “surface-line-surface” structure not only facilitates the migration and charge transfer of ions inside, but also provides more active electrosorption sites. When assembled as the flow electrode of the flow electrode capacitive deionisation (FCDI) system, the desalination capacity of the electrode was improved from 25.32 mg g−1 to 53.12 mg g−1. Therefore, the C@FeS composite is expected to provide a new candidate electrode material for the FCDI system, which will make the future desalination process more cost-effective and efficient.

High-performance flexible CoFe2O4/N-doped carbon nanofiber composite anode materials for sodium-ion batteries

Graphite is traditionally used as an anode material but is unsuitable for use in sodium-ion batteries because it has a low specific capacity and poor safety characteristics, it is therefore necessary to develop alternative anode materials. Flexible CoFe2O4 nanoparticle/N-doped carbon nanofiber films were prepared by electrospinning and calcination. The advantages of this process included inexpensive starting materials, easy preparation, and suitability for commercialization. The inherent shortcomings of CoFe2O4, such as poor electronic conductivity and large changes in volume, were mitigated via elemental doping and the formation of composites with high-quality carbon materials. Nitrogen-doped carbon nanofibers with large specific surface areas and superior mechanical properties were used as the supporting skeleton of the material. These nanofibers limited the volume expansion of CoFe2O4 throughout the cycling process and increased the ion diffusion velocity in the material. The optimal integration of nanoscale CoFe2O4 particles, which possess a higher theoretical specific capacity, with a nitrogen-doped carbon nanofiber conductive framework featuring a crosslinked three-dimensional structure facilitated the infiltration of the electrolyte into the electrode. This integration reduced the diffusion distance of sodium ions and effectively reduced the volume expansion of the material, as well as damage to the material during the electrochemical reaction. After 200 cycles at a current density of 0.1 A g−1, it provided a high sodium storage capacity of 365.7 mA h g−1. The capacity was maintained at 176.3 mA h g−1 even at a high current density of 2 A g−1. Exhibits good cycle stability.

High-performance α-Fe2O3 nano cubes as anode for supercapacitors

Abundant availability, high theoretical specific capacitance and low cost of transition metal oxides such as iron oxides, make them attractive as electrode materials for energy storage. In order to achieve improved performance, high conductivity, shorter ion-diffusion path, and faster ion accessibility, rational design of morphology of electrode material is highly desirable. We have successfully synthesized mesoporous α-Fe2O3 nanocubes to achieve high specific capacitance and better retention. The as-prepared and annealed α-Fe2O3 nanocubes show high reversible redox activity along with good thermodynamic stability. These nanostructure give rise to high specific capacitance and ~90 % of the capacitance can be retained even after 1000 redox cycles, suggesting good cyclic stability. The electrochemical performance of mesoporous α-Fe2O3 nanocubes is attributed to the morphological features, which results in efficient K+ ion transport into the pores. A two electrode α-Fe2O3//NiO device is fabricated, which shows excellent power and energy density of ∼627 W/kg and ∼23.32 Wh/kg, respectively. Our work demonstrates that 3D nanoporous α-Fe2O3 electrodes forms promising material system as anode for improved charge storage performance.

Analysis of interlayer dependency of MoS2/g-C3N4 heterostructure as an anode material for sodium-ion batteries

In this present work, we explore the effectiveness of layered molybdenum disulfide (2H-MoS2) and graphitic carbon nitride (g-C3N4) heterostructure as anode for Sodium-Ion Batteries (SIBs) by using first principles analysis. To study the anode properties, we varied the interlayer distance between 2H-MoS2/g-C3N4 as 3Å, 6Å, 9Å,12 Å, and 14 Å between MoS2 as substrate and g-C3N4 as top layer. The fundamental properties, such as structural stability and electronic structure were analysed for the respective systems. The adsorption kinetics of Na ion on the g-C3N4 layer were analysed by performing molecular dynamics (MD) simulations to understand the adsorption mechanism better. Our results showed that the interlayer distance of 6 Å with formation energy of −4.31 eV, the theoretical specific capacity value of 765.32 mAhg−1, the average electrode potential is between 0.8 and 1.3 V and the adsorption energy of −2.16 eV is suitable for MoS2/g-C3N4 based anodes for Na ion batteries.