Theoretical Specific Capacity Research Articles

Cu@MOF based composite materials: High performance anode electrodes for lithium-ion and sodium-ion batteries

In order to satisfy the increasing demand for energy, it is essential to improve the efficiency of lithium-ion batteries (LIBs) and sodium-ion batteries (SIBs) batteries. Metal selenides (MSes) have a high theoretical specific capacity, can be designed in a variety of ways, conduct electricity well, can change morphology easily, and have a multi-electron reaction mechanism. These characteristics make them very competitive as anode materials for LIBs and SIBs. Herein, we synthesise Cu@MOF and Cu@NH2-MOF as the precursor to prepare Cu1.95Se embedded into porous carbon matrix (Cu1.95Se@PC) and porous-N-doped carbon matrix (Cu1.95Se@NPC) via pyrolysis process of Cu@MOF and Cu@NH2-MOF, respectively. Cu1.95Se@PC and Cu1.95Se@NPC electrodes for half-cell LIBs and SIBs exhibit a high reversible capacity of 313.1, 480.9 (for LIBs), 216.3 and 303.8 (for SIBs) mAhg−1after 1000 cycles at 2 A g−1, respectively. We assess the electrochemical performance of the Cu1.95Se@PC and Cu1.95Se@NPC anodes by integrating them with commercially available LiFePO4 (LFP) into full-cell LIBs. The LFP//Cu1.95Se@PC and LFP//Cu1.95Se@NPC full-cells have discharge capacities of approximately 330 and 293 mAh g−1 at 0.3 A g−1 at the initial cycle. In order to explore the sodium storage mechanism of the Cu1.95Se composites, we conducted an in situ XRD test during the first charge/discharge cycle, considering their favourable cycling and rate performance. Our work provides a promising anode electrode material for both half-cell LIBs and SIBs with high volume utilization and superior electrochemical performances.

Facile synthesis of Co/Fe bimetallic doped Ni3S2 nanosheets and supercapacitor performance

Ni3S2 is an outstanding electrode material due to its high theoretical specific capacity, however, in practical research, the higher theoretical capacity is difficult to show, and the change of the structure in the cycling process affects the cycling stability, which limits its practical application. To address these issues, this study presents a strategy to synthesize Fe and Co bimetallic doped Ni3S2 nanosheets on nickel foam (NF) surface. This strategy introduces bimetallic atoms quickly and easily while synthesizing nanosheet structures, and the resulting synergistic interactions between the bimetals and the mutual support effect of the nanosheets can effectively enhance electron transfer and improve cycling stability. The electrochemical results show that the Fe and Co-doped sample (Ni3S2-Co/Fe-5) exhibits a specific capacitance of 3351 F·g−1 at 1 A·g−1 in the three-electrode system, which is nearly five times higher than the specific capacity of the undoped Fe and Co-doped sample (Ni3S2), and the capacity retention rate after cycling 5000 cycles at a current density of 10 A·g−1 is 100 %, the prepared sample (Ni3S2-Co/Fe-5) was assembled with activated carbon (AC) to form a hybrid supercapacitor, which could provide a maximum power density of 9818 W·kg−1, a maximum energy density of 66.25 Wh·kg−1, and a capacity retention of 94.5 % after 10,000 cycles, with a capacity loss of only 5.6 %.

The Effect of Nickel Addition on α-Fe2O3 Synthesis Using NaOH and Application as Lithium-Ion Battery Anode Material

Research has been conducted in the pursuit of developing the performance of batteries. The increasing demand for electronic devices and electric vehicles has driven the development of high-performance lithium-ion batteries (LIBs). Among the various anode materials, α-Fe2O3 has attracted significant attention due to its high theoretical specific capacity of 1007 mAh/g. However, its low conductivity and poor rate capability limit its practical application. To address these issues, this study investigates the addition of nickel (Ni) into α-Fe2O3 through a co-precipitation method. The synthesized materials were characterized using Fourier Transform Infrared Spectroscopy (FTIR), X-ray Diffraction (XRD), and Scanning Electron Microscopy with Energy-Dispersive X-ray spectroscopy (SEM-EDX). The electrochemical performance was evaluated using an LCR meter and charge-discharge cycling. The results showed the addition of Ni improved the conductivity of the α-Fe2O3 material. The optimal Ni content was found as much as 18×10-4 mol which exhibits the highest conductivity and specific capacity. The synthesized α-Fe1.965Ni0.035O3 material demonstrated a specific charging capacity of 1.8433 mAh/g and a specific discharging capacity of 1.8388 mAh/g. These findings suggest that Ni-doped α-Fe2O3 has the potential to be a promising anode material for high-performance lithium-ion batteries (LIBs).

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.

UIO-66-NH2 as Photo-Assisted Li-O2 Battery Cathode for High-Current Discharge.

Li-O2 batteries (LOBs) have garnered significant attention in recent years due to high theoretical specific capacity, however, the sluggish charge-discharge reaction kinetics and rapid failure under high current densities have hindered their further application. This work presents a photo-responsive catalyst (UIO-66-NH2) supported on carbon cloth, which could enhance the reaction kinetics of LOBs and improve the discharge capacity under high current densities. It demonstrates that under light, the overpotential decreases by 0.9 V, and the discharge capacity reaches an impressive 4.8 mAh cm-2 at a current density of 0.5 mA cm-2. This finding is expected to inspire the development of various novel MOF-based photoelectrodes for LOBs.

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.

A Novel Anion Receptor Additive for -40ºCSodium MetalBatteriesby Anion/Cation Solvation Engineering.

Sodium metal batteries, known for their high theoretical specific capacity, abundant reserves,and promisinglow-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 pinalol ester (ABAPE), is proposed to weaken the coupling between anions and cations and accelerateNa+transport kinetics.The results of theoretical calculations and X-ray photoelectron spectroscopy with deep Ar-ion etching demonstrate thatthe introduction of this additive alters the solvation structure of Na+, reducesthe desolvation barrier and formsa stable and dense electrode-electrolyte interface. Moreover, ABAPE forms hydrogen bonds (-NH···O/F) with H2O/HF, effectively preventing the hydrolysis of NaPF6and 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) full cell with the addition of ABAPE maintains a capacity retention of 84.29% at 1 C after1200 cycles and presents no capacity decayover 150 cycles at -40°C.

Mechanically Robust Polyimide Binder Realizes Stable and High Electrochemical Performance for Micro-Silicon Anodes in Lithium-Ion Batteries.

Silicon anodes have been considered one of the most promising candidates for Li-ion batteries due to their high theoretical specific capacity. However, the practical use of silicon anodes is impeded due to side reactions and volumetric change (from 300~400%) charge/discharge process. Binders played a crucial role in Li-ion batteries by effectively mitigating the stress resulting from the volumetric expansion in silicon-based anodes. Herein, we developed a mechanically stable polyimide binder PI-CF3 that introduced trifluoromethyl and hydroxyl groups for commercial microparticular silicon anodes. With a highest Young's modulus of ~921.1 MPa, the binder presented the maximum resilience during the charging and discharging of Micro-Si, integrating the morphology, and reducing the degree to which the electrode disrupted ion and electric pathways. Moreover, -OH and -CF3 groups of the binder could potentially interact with oxide layer at the surface of silicon through hydron bonds, and thereby results in a cross-linking network to improve interface stability during cycling. The as-prepared PI-CF3 binder with excellent intrinsic mechanical and electro-rich groups stabilizes the electrode structure and facilitates fast Li+ transportation. Consequently, micro-Si anode delivered initial specific capacity of 1838 mAh g-1 (at 0.6 A g-1), and at high mass (Si loading = 0.78 mg cm-2) these was retained about 1219 mAh g-1 after 330 cycles (only -0.061% capacity reduction per cycle).

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.

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.

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.

Facile synthesis of Cu2O nano-microspheres anode for lithium-ion batteries

Transition metal oxide anode materials exhibit high theoretical specific capacities and can meet the energy density requirements through reasonable design. In this work, a facile wet-chemical method to fabricate Cu2O nano-microspheres anode for lithium-ion batteries with controllable size varied from 0.4 ∼ 1.2 μm is introduced, which basically using copper acetate as copper precursor and ascorbic acid as reducing agent. The solvent composition (DI water only or DI water:Ethanol = 1:1), solution alkalinity (amount of NaOH input), and synthesis temperature are investigated as factors affecting the size and morphology of Cu2O nano-microspheres. The samples are characterized by X-ray diffraction, transmission electron microscope and scanning electron microscope. Nanoparticle cluster structure is observed in the reaction product with the bi-solvent system. With the optimized synthesis condition, the prepared Cu2O anode (size of ∼ 455 ± 41 nm) delivers an initial discharge capacity of 539 mAh/g at a current density of 0.5C, 100 cycles of cyclic discharge at 0.5C with a capacity retention rate of 84.73 %. At the current density of 2C, the specific capacity is 347 mAh/g. Even at a large current density of 5C, the specific capacity is still as high as 219 mAh/g, indicating good rate capability.