High-performance Lithium-ion Batteries Research Articles

Facile one-pot synthesis of Bi2S3 nanorod @ N, S co-doped carbon composite for high performance lithium ion batteries

Bismuth sulfide is favoured in lithium ion batteries due to its high specific capacity of 625 mAh/g. However, the Bi2S3 anode faces severe volume expansion problems during the lithium intercalation process, resulting in continuous electrode fragmentation and rapid degradation of lithium storage performance. In this study, Bi2S3 nanorod@N, S co-doped carbon composite prepared by a simple sintering method was used as the anode material for lithium ion batteries. 1D Bi2S3 nanorods with a length of 1 μm and a diameter of 50 nm were loaded in situ on 2D N, S co-doped carbon nanosheets. This unique structure can not only alleviate the volume change of bismuth sulfide, but also effectively shorten the diffusion distance of lithium ions, thereby improving the cycling stability and rate capability at the same time. The discharge capacity of Bi2S3@N, SC remained at 583.4 mAh g –1 after 400 cycles at 0.5 A g–1. Even at a high current density of 2 A/g, the discharge capacity of Bi2S3@N, SC still reached 374.3 mAh g –1. This simple method also can be extended to the preparation of other metal sulfide composites.

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).

Embedment of Molybdenum Disulfide in Electrospun Fibers as an Integrated Cathode for Lithium-Ion Batteries

As an important component of LIBs, the electrode material plays a crucial role in determining the lithium (Li) storage performance in LIBs. In this study, MoS2 nano-flowers were synthesized using a one-pot hydrothermal method. The resulting MoS2 nano-flower, along with PAN, were used as raw materials for electrospinning. After annealing treatment, MoS2/(carbon nanofibers) CNFs nano-composites coated with carbon fibers were formed. The CNFs coating exhibited electrical conductivity and enhanced structural stability of the MoS2 due to the stabilizing effect of the carbon fibers. Additionally, electrochemical tests, including CV and GCD, indicated that the optimal capacity and cycling stability were achieved when the MoS2 content was 10%. The results indicated that the charge/discharge capacity of MoS2/CNFs-10% at a current density of 100 mA/g was ~650 mAh/g. After the cycling current returned to 100 mA/g, the current recovery was ~600 mAh/g, thereby indicating outstanding cycling stability. Accordingly, our fabrication technique and new insight could both widen design strategy of multicomponent composite electrode materials and promote the practical applications of the latest emerging transition metal sulfides in next-generation high-performance lithium-ion batteries.

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.

Design of Ligand-Nonbridging Sites in Metal-Organic Frameworks for Boosting Lithium Storage Capacity.

Metal-organic frameworks (MOFs) are lagging in the use of lithium-ion batteries (LIBs), ascribing to full coordination between metal nodes and organic ligands, to a large extent. By integrating a modulator into a ligand with missing bridging functionality, this study elucidates the role of non-bridging defect sites in MOFs in tailoring lithium storage performance. A fully bridged pristine MOF (p-MOF) utilizing the meso-tetra(4-carboxylphenyl) porphyrin ligand is compared with a modified MOF containing non-bridging defects (d-MOF) introduced by a homologous ligand, tris(4-carboxyphenyl) porphyrin. Spectroscopic and cryogenic low-dose electron microscopy techniques verify the presence of non-bridging defect sites in the d-MOF and reveal their explicit local structure. Density functional theory calculations show significantly enhanced Li+ adsorption energies and reduced Li+ migration barriers at the non-bridging sites in the d-MOF compared to the fully bridging sites in the p-MOF. As a result, the d-MOF exhibits exceptional lithium storage performance, achieving a high capacity of 761 mAh g-1 at 0.05 A g-1 and superior rate performance of 203 mAh g-1 at 5 A g-1, which substantially outperform the p-MOF. This study highlights the potential of modulating MOFs with non-bridging defects to develop high-performance LIBs.

Monofluorinated Phosphate with Unique P-F Bond for Nonflammable and Long-Life Lithium-Ion Batteries.

Lithium-ion batteries (LIBs) with conventional carbonate-based electrolytes suffer from safety concerns in large-scale applications. Phosphates feature high flame retardancy but are incompatible with graphite anode due to their inability to form a passivated solid electrolyte interphase (SEI). Herein, we report a monofluorinated co-solvent, diethyl fluoridophosphate (DEFP), featuring a unique P-F bond that allows a trade-off between safety and electrochemical performance in LIBs. The P-F bond in DEFP weakens ion-dipole interactions with Li+ ions, lowering the desolvation barrier, and simultaneously reduces the lowest unoccupied molecular orbital (LUMO) of DEFP, promoting the formation of a robust and inorganic-rich SEI. Additionally, DEFP exhibits improved thermal stability due to both robust SEI and the inherent flame-retardant properties of the P-F bond. Consequently, the optimized DEFP-based electrolyte exhibits improved cyclability and rate capacity in LiNi0.8Co0.1Mn0.1O2||graphite full cells compared with triethyl phosphate-based electrolytes and commercial carbonate electrolytes. Even at a low E/C ratio of 3.45 g Ah-1, the 1.16 Ah NCM811||Gr pouch cells achieve a high capacity retention of 94.2 % after 200 cycles. This work provides a promising approach to decouple phosphate safety and graphite compatibility, paving the way for safer and high-performance lithium-ion batteries.

Fluorine-Doping Carbon-Modified Si/SiOx to Effectively Achieve High-Performance Anode.

To address the significant challenges encountered by silicon-based anodes in high-performance lithium-ion batteries (LIBs), including poor cycling stability, low initial coulombic efficiency (ICE), and insufficient interface compatibility, this work innovatively prepares high-performance Si/SiOx@F-C composites via in situ coating fluorine-doping carbon layer on Si/SiOx surface through high-temperature pyrolysis. The Si/SiOx@F-C electrodes exhibit superior LIB performance with a high ICE of 79%, exceeding the 71% and 43% demonstrated by Si/SiOx@C and Si/SiOx, respectively. These electrodes also show excellent rate performance, maintaining a capacity of 603 mAhg-1 even under a high current density of 5000 mAg-1. Notably, the Si/SiOx@F-C electrode sustains a high reversible capacity of 829 mAh g-1 at 1000mA g-1 over 1400 cycles, and 588 mAhg-1 at 3000 mAg-1 even over 2400 cycles, capacity retention of up to 82.12%. Comprehensive characterization and analysis of the fluorine-doped carbon layer reveal its role in enhancing electrical conductivity and preventing structural degradation of the material. The abundant fluorine in the coating layer significantly increases the LiF concentration in the solid electrolyte interface (SEI) film, improving interfacial compatibility and overall lithium storage performance. This method is both straightforward and effective, providing a promising blueprint for the broader application of Si-based anodes in advanced lithium batteries.

N, P co-Doped Hard Carbon Anodes for High-Performance Lithium-Ion Batteries with Enhanced Capacity Retention and Cycle Stability.

Compared to the traditional graphite anode, heteroatom-doped polymer carbon materials have high capacity retention due to their high porosity and porous structure. Therefore, they have great potential for application in lithium-ion battery (LIB) anodes. In this work,an N, P co-doped precursor polymer material (MBPp), synthesized via a one-pot method using bisphenol-A (C-source), melamine (N-source), and 9,10-Dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (P-source). The resulting N, P-co-doped hard carbon materials (MBPs) were prepared at various pyrolysis temperatures, yielding microporous, mesoporous, and macroporous structures. MBP materials demonstrated excellent electrochemical performance as LIB anodes. Notably, MBP-900 achieved a reversible capacity of 262 mAh g-1 at 1000 mA g-1 (in 0.005-2.0 V voltage range) with a capacity retention rate of 97.2% after 1000 cycles. These findings highlight the significance of MBP materials, which possess numerous defects, large layer gaps, and excellent cycle stability, in advancing the development of polymer anode materials for LIBs.

Robust, High-Temperature-Resistant Polyimide Separators with Vertically Aligned Uniform Nanochannels for High-Performance Lithium-Ion Batteries.

Separator is an essential component of lithium-ion batteries (LIBs), playing a pivotal role in battery safety and electrochemical performance. However, conventional polyolefin separators suffer from poor thermal stability and nonuniform pore structures, hindering their effectiveness in preventing thermal shrinkage and inhibiting lithium (Li) dendrites. Herein, we present a robust, high-temperature-resistant polyimide (PI) separator with vertically aligned uniform nanochannels, fabricated via ion track-etching technology. The resultant PI track-etched membranes (PITEMs) effectively homogenize Li-ion distribution, demonstrating enhanced ionic conductivity (0.57 mS cm-1) and a high Li+ transfer number (0.61). PITEMs significantly prolong the cycle life of Li/Li cells to 1200 h at 3 mA cm-2. For Li/LiFePO4 cells, this approach enables a specific capacity of 143 mAh g-1 and retains 83.88% capacity after 300 cycles at room temperature. At 80 °C, the capacity retention remains at 85.92% after 200 cycles. Additionally, graphite/LiFePO4 pouch cells with PITEMs display enhanced cycling stability, retaining 73.25% capacity after 1000 cycles at room temperature and 78.41% after 100 cycles at 80 °C. Finally, PITEMs-based pouch cells can operate at 150 °C. This separator not only addresses the limitations of traditional separators, but also holds promise for mass production via roll-to-roll methods. We expect this work to offer insights into designing and manufacturing of functional separators for high-safety LIBs.

The reduced graphene oxide conductive additives with a certain defect concentration enabling rate-capability of lithium-ion batteries

Graphene as conductive additives for enhancing the electrochemical performance of commercial cathode materials (e.g., LiFePO4, LiCoO2, and LiMn2O4) in advanced Li-ion batteries (LIBs) has attracted great attention in recent years. However, the LiFePO4 and LiCoO2 electrodes usually show a poor rate capability when using graphene as the conductive additive, since its planar structure hinders ion transmission. Herein, a variety of reduced graphene oxides (rGO-x) have been successfully prepared using the modified Hummer's method followed by calcination. The results show that due to a large specific area and moderate defect density, rGO-5 can ensure good enough interfacial contact between active material particles and collector, thus maintaining fast electron/ion transportation. It has been found that LiFePO4 and LiCoO2 electrodes exhibit good lithium storage properties of 160.95 and 139.41 mA h g-1 at a rate of 0.1 C when rGO-5 is utilized as a conductivity additive. Meanwhile, combined with the electrochemical impedance and kinetic exploration, it can be seen that the LiFePO4 and LiCoO2 electrodes demonstrate a high Li+ diffusion coefficient (DLi+) of 6.7 × 10-14 cm2 s-1 and 4.3 × 10-13 cm2 s-1, respectively. Therefore, this research sheds new light on the practical utilization of rGO additives in high-performance lithium-ion batteries.

Dual active sites of N-rich triptycene-based 2D conductive metal–organic framework with 3D extended structures in high-performance lithium-ion batteries

Two-dimensional conductive metal–organic frameworks (2D c-MOFs) have attracted much attention in energy storage due to their special conjugated structures and electronic properties. However, the insufficient exposure of the active site due to layer stacking and the non-redox-active ligand molecules are detrimental to the specific capacity. In this study, a nitrogen-rich triptycene-based 2D c-MOF (M−TH5) with vertical extension was synthesized for the first time as an anode material. The triptycene-based ligand structure confers a 3D extension of the MOF alleviating the stacking problem and allowing full exposure of its active site. Furthermore, M−TH5 has a dual redox center (TH5 and MO4 units containing N sites), which can provide additional lithium storage sites. Expectedly, Mn-TH5 compared to Co-TH5 exhibits higher initial capacity (486.3 mAh·g−1 at 100 mA·g−1) and excellent long-term cycling stability (capacity retention of 91.9 % at 500 mA·g−1 after 400 cycles). Experimentally and computationally, the flower-like morphology and the nitrogen-rich system with three-dimensional (3D) expansion have more exposed active sites to facilitate Li+/e- transport. This finding provides new opportunities to improve anode material properties by integrating multiple active centers into 2D c-MOF

Exploring the potential and impact of single-crystal active materials on dry-processed electrodes for high-performance lithium-ion batteries

Roll-to-roll powder-to-film dry processing (DP) and single-crystal (SC) active materials (AMs) with many advantages are two hot topics of lithium-ion batteries (LIBs). However, DP of SC AMs for LIBs is rarely reported. Consequently, the impact of SC AMs on dry-processed LIBs is not well understood. Herein, for the first time, via a set of experimental and theoretical studies of the conventional polycrystalline-AM- and SC-AM-based DPed electrodes (DPEs), this work not only reports a high-performance dry SC-AM cathode for LIB manufacturing, but also establishes some fundamental understanding of SC-based dry-processed electrodes, including their morphology, structure, mechanical strength, electronic conductivity and LIB electrochemical behavior. The results suggest that DP of SC AMs is promising, which can dramatically improve the electrochemical kinetics at electrode level and particle level. Specifically, for the rate capability and long-term cyclability in full cells, SC DPEs exhibit a discharge specific capacity of 152.1 mAh g−1 at 1C and a capacity retention rate of 79.9 % at C/3 over 500 cycles, which are superior to those of PC DPEs (135.6 mAh g−1 and 68.3 %) at the same conditions and are further confirmed by the simulation data from the theoretical modelling study. Therefore, this comprehensive work marks a significant milestone for DP strategy and SC AMs, enlightening future research and development of LIB manufacturing.

Intelligent dual-anode strategy for high-performance lithium-ion batteries

Intelligent dual-anode strategy for high-performance lithium-ion batteries

In situ construction of an electron-withdrawing polymer coating layer on NCM811 interface for high-performance lithium-ion batteries

The stability of electrolyte in Lithium-ion batteries (LIBs) is strongly influenced by its internal molecular structure, which can be affected by the electronegativity of electron groups. During the charging process of the NCM811 cathode electrode, electron-deficient transition metal ions in the cathode tend to extract electrons from the surrounding electrolyte solvent, weakening its structural stability and leading to oxidative degradation. To address this issue, a novel approach involving the formation a polymer coating layer (PCL) on the NCM811 cathode through in-situ self-polymerization of Tetravinylsilane (TVSi) to enhance LIB performance and stability. The electron-withdrawing effect and the presence of the C=C bond in TVSi help stabilize the cathode-electrolyte interface and inhibit oxidative degradation. The PCL increases the electrolyte's onset oxidation potential to 5.02 V. The resulting NCM811 batteries exhibit an improved discharge capacity retention of 80% at 1C over 140 cycles. This study presents an innovative approach for improving the stability and performance of LIBs by utilizing TVSi, characterized by its electron-withdrawing effect and C=C bond as a PCL on the NCM811 cathode material.

Mn and Ti Co-doping of LiNiO2 to Improve Performance

LiNiO2 (LNO) has high capacity but suffers from structural instability and capacity fade, which limits its practical use in lithium-ion batteries. This study proposes co-doping LNO with Mn and Ti (MnTi25) as a strategy to overcome these issues. MnTi25 was thoroughly characterized, revealing improved structural stability and significantly reduced cation mixing compared to pristine LNO. The half-cell performance of MnTi25 is noteworthy, exhibiting a capacity similar to the established 4% Mn-substituted ZoomWeMn4 standard, demonstrating efficient Li-ion extraction and insertion. Additionally, full-cell testing against a graphite anode shows that MnTi25 delivers a capacity almost identical to a commercial LNO-based material. This promising achievement highlights the effectiveness of co-doping in addressing LNO's limitations while preserving its high-capacity potential. This study demonstrates that MnTi25 can be a promising cathode material for high-performance lithium-ion batteries by tailoring the material's structure through co-doping.

Enhanced graphitization of CO2-derived carbon anodes via Joule heating reformation for high-performance lithium-ion batteries

Molten salt electrolysis of CO2 represents a promising technology for highly efficient CO2 capture and the production of economically valuable CO2-derived carbon materials. In this study, we established a 100-A-scale molten salt CO2 electrolysis cell to synthesize hundreds of grams of CO2-derived carbon. Subsequent Joule heating at 2800 °C transformed these materials into high-quality graphite. Further composite modification with asphalt and petroleum coke effectively reduced surface area, resulting in high-performance graphite for lithium-ion battery. The CO2-derived graphite anodes demonstrated high reversible capacities ranging from 297.7 to 378.1 mAh g−1, exhibiting outstanding rate capability and stability over 300 charge-discharge cycles at a current density of 1 A g−1. Finally, we assembled a coin full-cell using AG-2/2/6 anode and LFP cathode, which demonstrated good cycling performance. XPS analysis revealed a significant reduction in oxygen content by the post-reformation, facilitating the formation of highly graphitized structures. This study not only pioneers the up-class synthesis of CO2-derived carbon but also underscores its potential for sustainable energy applications, particularly in lithium-ion battery technology.

Synthesis of graphitic carbon from empty palm oil fruit bunches through single-step graphitization process using K2FeO4-KOH catalyst as lithium ion battery anode

This research aims to optimize the graphitization process of carbon derived from Empty Palm Oil Fruit Bunches (EPOFB), a renewable biomass source, using a single-step K₂FeO₄-KOH impregnation-activation method. The results demonstrate that increasing the mass of K₂FeO₄, up to the optimal level, enhances the degree of graphitization, as confirmed by XRD and Raman spectroscopy. Optimal performance is observed with a catalyst mass of 0.11 g K₂FeO₄ in the C_ K₂FeO₄(0.11)KOH_800 sample, which exhibits a d002 spacing of 0.3356 nm, an IG/ID ratio of 2.42, a high surface area of 787.767 m²/g, and clearly defined graphitic layers in TEM images. Electrochemical testing of C_ K₂FeO₄(0.11)_KOH_800 reveals promising results, including the lowest charge transfer resistance (Rct) of 87.18 Ω, a significant area under the curve in cyclic voltammetry, a charging capacity of 330.3 mAh g⁻¹ at 0.1 C, with an excellent rate capability of 183 mAh g⁻¹ at 1 C after 100 cycles, maintaining a retention rate of 68.2 %. The single-step K₂FeO₄-KOH impregnation-activation method effectively enhances the graphitization of EPOFB-derived carbon, offering potential applications in high-performance lithium battery anodes.

Poly(Acrylic Acid)-Based Polymer Binders for High-Performance Lithium-Ion Batteries: From Structure to Properties.

Poly(acrylic acid) (PAA) and its derivatives have emerged as promising candidates for enhancing the electrochemical performance of lithium-ion batteries (LIBs) as binder materials. Recent research has focused on evaluating their ability to improve adhesion with silicon (Si) particles and facilitate ion transport while maintaining electrode integrity. Various strategies, including mixing modifications and copolymerization methods, are highlighted and the structural and physicochemical properties of these binders are examined. Additionally, the interaction mechanisms between PAA-based binders and active materials and their impact on key electrochemical properties such as initial Coulombic efficiency (ICE) and cycle stability are discussed. The findings underscore the efficacy of tailored PAA-based binders in enhancing the electrochemical properties of LIBs, offering insights into the design principles and practical implications for advanced battery materials. These advancements hold promise for developing high-performance lithium batteries capable of meeting future energy storage demands.

Triazine-Based Large-Sized Single-Crystalline Two-Dimensional Covalent Organic Framework for High-Performance Lithium-Ion Batteries.

A large-sized single crystalline 2D COFs with excellent crystallinity and stability was prepared through the traditional thermal solvent method. The electrochemical performance can be significantly enhanced using a straightforward hybrid approach that involves in situ growth of the 2D COFs on multi-walled carbon nanotubes (MWCNTs). Both the advantages of COFs and CNTs are mutually enhanced. The single-crystalline feature of the obtained COFs improves the structural integrity and brings excellent chemical and electrochemical stabilities for lithium-ion battery applications. The resultant COF-CNT core-shell hybrids greatly improved the conductivity and demonstrated excellent lithium-ion storage performance with a high capacity of 228 mAh g-1 (0.2 A g-1).

Electric Field and Nanocontact Effects in Metal-Organic Framework/Li6.4La3Zr1.4Ta0.6O12 Ionic Conductors for Fast Interfacial Lithium-Ion Transport Kinetics.

The slow ion transport kinetics inside or between the nanofillers in composite polymer electrolytes (CPEs) lead to the formation of lithium dendrites for solid-state lithium batteries. To address the critical issues, CPEs (U@UNL) composed of a UIO-66@UIO-66-NH2 (U@UN) core-shell heterostructure and Li6.4La3Zr1.4Ta0.6O12 (LLZTO) filler is designed. Due to the different band structures of the U@UN heterostructure, a built-in electric field is constructed to promote the transfer kinetics of carriers. Besides, the introduction of LLZTO facilitates the formation of a close nanometer contact interface between U@UN and LLZTO, reducing interface impedance and accelerating the lithium-ion transfer rate. As a benefit from the built-in electric field and the nanometer contact interface, U@UNL exhibits a wide electrochemical window of 5.17 V, a large lithium-ion transference number of 0.76, and a high ionic conductivity of 3.50 × 10-3 S cm-1. Consequently, the U@UNL electrolyte possesses excellent interfacial stability against Li metal after 1200 h at 0.1 mA cm-2 and shows a high specific capacity of 160.2 and 152.6 mAh g-1 at 0.5 and 1 C, respectively. This work proposes a complete strategy for building high-performance solid-state lithium batteries by a built-in electric field and nanometer contact interface between U@UN and LLZTO.