Anodes For Lithium-ion Storage Research Articles

Unraveling the origin of the high reversibility in entropy-stabilized rocksalt-type (Mg0.2Co0.2Mn0.2Ni0.2Zn0.2)O anodes for lithium-ion storage

Entropy-stabilized rocksalt-type oxides, composed of multiple components, are increasingly recognized as highly promising materials for energy storage applications. In this study, a novel anode material, (Mg0.2Co0.2Mn0.2Ni0.2Zn0.2)O, demonstrates exceptional reversible specific capacity of 773.4 mAh g−1 even after 200 cycles at 0.1 A g−1. Density functional theory (DFT) analysis reveals superior electrical conductivity of (Mg0.2Co0.2Mn0.2Ni0.2Zn0.2)O compared to individual oxides like CoO, which has the potential to enhance electronic transfer to improve electrochemical performance. In situ transmission electron microscopy (TEM) observations confirm the reversible crystal structure of rocksalt-type (Mg0.2Co0.2Mn0.2Ni0.2Zn0.2)O anodes, with only ∼36.8 % volume expansion in four cycles. This investigation offers insights into the (de)lithiation process at a microscopic scale, shedding light on the origins of high reversibility and guiding the design of future high-entropy materials. Entropy-stabilized rocksalt-type (Mg0.2Co0.2Mn0.2Ni0.2Zn0.2)O oxides exhibit excellent properties, positioning them as promising candidates for lithium-ion batteries (LIBs) anode materials.

TiO2 embedded in ultrathin N-doping carbon nanosheets derived from shape-engineered titanium metal-organic frameworks for lithium-ion storage

The utility of TiO2 as an anode for lithium-ion storage is hindered by low conductivity and sluggish ionic diffusion. Here, the 2D N-doped carbon-wrapped TiO2 (TiO2 @NC) composite with a thickness of 5.5 nm derived from the 2D metal-organic framework was designed. This composite consisting of TiO2 nanoparticles embedded in ultrathin N-doping carbon was used to address the rate and cyclability of Li-ion batteries. The 2D nanosheet morphology obtained from Ti8O8(OH)4(BDC-NH2)6（NH2-MIL-125 (Ti)）effectively increases the specific surface area and shortens the electron/ion transport pathway. The chemical bond of Ti-C-O between TiO2 nanocrystals and N-doping carbon further improve conductivity. Due to its unique structure, the produced TiO2 @NC composite shows excellent cyclability with a reversible capacity of 110 mAh g–1 after 2000 cycles at 0.5 A g–1. Furthermore, the 2D TiO2 @NC exhibits outstanding rate performance (71 mAh g–1 at 5 A g–1) compared to bulk TiO2 @NC. This general concept can be extended to the development of metal oxide materials based on insertion mechanisms, such as Nb2O5.

Adsorption-Assisted Redox Center in Porous Organic Frameworks for Boosting Lithium Storage.

Due to the designable structure and capacity, organic materials are promising candidates for lithium-ion batteries. Herein, we report a novel type of porous organic frameworks (POFs) based on the coupling reaction of diazonium salt as the anodes for lithium ion storage. The active center containing an azo group and the adjacent lithium-philic adsorption site is constructed to investigate the electrochemical behaviors and reaction mechanism. As synthesized POF material (named as POF-AN) exhibits high reversible lithium storage capacities of 523 mAh g-1 at 0.5 A g-1 and 445 mAh g-1 at 2.0 A g-1 after 1500 cycles, showing excellent cycle stability and rate performance. The detailed characterizations reveal that the azo group can act as an electrochemical active site that reversibly bonds with Li-ions, and the adjacent oxygen atoms can electrostatically adsorb with Li-ions to promote the lithium storage reaction. This adsorption-assisted three-atom redox center is beneficial to synergistically enhance the adsorption and intercalation of lithium ions, which can further improve the capacity and cycle stability. By replacing the precursor, it is also facile to synthesize more similar structure types. The reversible redox chemistry of the adsorption-assisted three-atom active center provides new opportunities for the development of long lifespan and high-rate organic anodes.

The effects of doped phosphorus on the electrochemical performance of hard carbon anode for lithium ion capacitors

Heteroatom is a practical tactic to improve the ability of carbon materials to store lithium ions. In this research, a series of hard carbon with different phosphorus species and contents were simply prepared by annealing the mixture of phytic acid and starch. By studying the phosphorus functional groups species and electrochemical performance of phosphorus-doped carbon, the relation of phosphorus species, phosphorus atoms contents and the Li-storage performance of samples have been closely related. In this context, the high content of phosphorus atoms not means a high specific capacity and the phosphorus-doped hard carbon will produce a higher specific capacity when the doping content of phosphorus atoms ranges around 1.8 %. As to the effect of phosphorus functional groups species on the electrochemical performance of hard carbon, the Li-ions may be stored more efficiently with the higher proportion of CP bonds in phosphorus functional groups species. In this regard, the understanding of how phosphorus functional groups species affect electrochemical performance on hard carbon will help better understand the effect of phosphorus doping on hard carbon anode for lithium ion storage. Meanwhile, it also will provide some insights and support for the application of phosphorus-doped electrodes.

Ultrathin graphdiyne oxide-intercalated MXene: A new heterostructure with interfacial synergistic effect for high performance lithium-ion storage

Two-dimensional (2D) layered heterostructures demonstrate strong interfacial synergistic effect, promote ion transfer and accelerate electrochemical reaction kinetics, and have great development potential in the field of energy storage. Here, ultra-thin 2D graphdiyne oxide (GDYO) was successfully prepared and creatively used as an intercalator to form a sandwich-like heterostructure with MXene (Ti3C2Tx) through electrostatic self-assembly. Intercalation of GDYO effectively extends the interlayer spacing of Ti3C2Tx nanosheets and meanwhile generates atomic interfacial electric fields within the heterostructure, leading to desirable pseudocapacitive behaviors and superior lithium-ion migration kinetics. Theoretical and experimental data reveal that the electrochemical performance of the heterostructure is superior to that of pure Ti3C2Tx or GDYO nanosheets when utilized as anodes for lithium-ion storage. A reversible capacity of ≈490.0 mAh g−1 at 2.0 A g−1 is attained by the Ti3C2Tx/GDYO-5 wt% heterostructure (≈770.0 mAh g−1 at 0.1 A g−1) with a long cycle life of 489.2 mAh g−1 after 1000 cycles.

High stability and high performance nitrogen doped carbon containers for lithium-ion batteries

For a long time, carbon has been an ideal material for various electrochemical energy storage devices and a key component in electrochemical energy storage systems due to its advantages of rich surface states, easy tenability, and good chemical stability. Stable and high-performance carbon materials can support future applications of high specific energy electrodes. Herein and for the first time, we have designed nitrogen-doped carbon hollow containers using oleylamine-coating TiO2 mesocrystals as a precursor with a high specific surface area of 1231 m2 g−1. When applied as an anode for lithium-ion storage, a reversible capacity of 774.5 mA h g−1 is obtained at a rate of 0.5 A g−1 after 200 cycles. Meanwhile, at an even higher rate of 2 A g−1, a capacity of 721.1 mA h g−1 is still achieved after 500 cycles. Moreover, the carbon containers remain structurally intact after a series of cycles. This may be attributed to the nitrogen atoms doped on the carbon surface that can absorb multiple lithium ions and enhance the structural stability. These results provide technical support for the development of high specific energy electrode materials.

Submicro-sized and partially etched V2AlxCTz as an anode for lithium-ion storage

Vanadium-based MXenes are prospective as anode materials in energy-storage devices including lithium-ion batteries (LIBs) but limited by their charge-discharge capacities. Herein, partially-etched V2AlxCTz with the average particle size of ~400 nm was synthesized using 40 wt% HF or mixed NaF+HCl solutions as etchants, respectively. V2AlxCTz etched by 40 wt% HF for 96 h at room temperature (RT) has more exceptional charge-discharge performances against mixed NaF+HCl solutions, with an average reversible capacity of ~450 mAh g−1 at 0.1 A g−1 in the 120 cycles and ~301.2 mAh g−1 at 0.5 A g−1 after 200 cycles in LIBs. The effect of etchants on electrochemical performances and lithium-ion (Li-ion) storage mechanism of V2AlxCTz was discussed comprehensively. Additionally, a Li-ion full cell using LiFePO4 as cathode has exhibited excellent electrochemical performance (150.4 mAh g−1 at 0.1 C). This work illustrates that partially-etched V2AlxCTz with the submicro-sized distribution is also a promising anode material for LIBs.

Triphenylamine-Contained Multiporous Polyimide: Its Preparation and Application as Anode for Lithium-Ion Storage

Abstract The three-dimensional (3D) multiporous structure polyimides were obtained by introducing of the triphenylamine (TPA) unit as linkage in the pyromellitic-based polyimide (N1) and the naphthalene-1,4,5,8-tetracarboxylic-based polyimides (N2), respectively. Then, the functional polyimides were explored as the anode of lithium ion batteries instead of as traditional cathode. As a result, the obtained triphenylamine-based polyimides exhibited a good reversible capacity and remarkably improved rate performance. Especially for the porous N1, it delivered a gradually increased capacity of up to 349 mAh/g during the cycle testing and a rate capacity of 400 mAh/g at an even high current density of 500 mA/g. Significant electrochemical performances for the triphenylamine-contained polyimide could be ascribed to the unique polyimide chemical structure and the constructed 3D multiporous structure with the high surface area (738 m2/g for N1 and 456 m2/g for N2), which benefited to excellent Li+ diffusion kinetics in porous electrode. This makes it promising as anode of rechargeable batteries with the remarkably electrochemical performances.

Correction: Multifunctional sulfur-mediated strategy enabling fast-charging Sb2S3 micro-package anode for lithium-ion storage

Correction for ‘Multifunctional sulfur-mediated strategy enabling fast-charging Sb2S3 micro-package anode for lithium-ion storage’ by Shaohua Wang et al., J. Mater. Chem. A, 2021, 9, 7838–7847, DOI: 10.1039/D0TA11954G.

Novel MXene-based hierarchically porous composite as superior electrodes for Li-ion storage

MXenes are widely investigated for electrochemical energy storage, sensors, and other fields, because of their excellent electrical conductivity and rapid ion transport. Nevertheless, the electrochemical properties and structural stability of MXenes are greatly restricted by the inherent self-restacking. Here we design and synthesize a series of hierarchically porous composites (C-Fe3O4/Ti3C2), where carbon-coated Fe3O4 (C-Fe3O4) acts as buttress to support the few-layered Ti3C2 MXene (f-Ti3C2) based on the hydrogen bonding interaction and Van der Waals force between the carbon coating layer and the f-Ti3C2. The self-restacking of f-Ti3C2 MXene and the sluggish reaction kinetics of Fe3O4 can be improved simultaneously when the C-Fe3O4/Ti3C2 composites are applied as anode for lithium-ion storage. The C-Fe3O4/Ti3C2 1:1 anode maintains ultrahigh reversible capacity of 1150 mAh g−1 at 1 A g−1 even after 1000 deep cycles, and 561 mAh g−1 at 5 A g−1, 340 mAh g−1 at 7 A g−1, showing excellent lithium-ion storage performance and superior structural stability that originated from the synergistic interaction between Fe3O4 and f-Ti3C2 MXene. The hierarchically porous composite opens up new possibilities in designing 2D MXene-based composites for catalytic, sensing, biomedical, energy storage materials.

A lightweight and low-cost electrode for lithium-ion batteries derived from paper towel supported MOF arrays.

Herein, Cu-doped Co-ZIF nanoplate arrays are uniformly grown on a commercial paper towel substrate first. After a subsequent annealing treatment, well-defined Cu-doped Co/CoO nanoparticles embedded in N-doped carbon hybrid nanoplate arrays supported on the carbon paper substrate (denoted as Cu-doped Co/CoO/NC NPAs@CP) are obtained, which exhibit excellent performance as a low-cost, lightweight and binder-free anode for lithium ion storage.

Nanocrystalline silicon embedded highly conducting phosphorus doped silicon thin film as high power lithium ion battery anode

In a search of high capacity anode for lithium ion batteries, nano architecture silicon appears as an interesting material despite of its volume change issues. Herein, we report phosphorous doped (n‒type) nanocrystalline silicon using plasma enhanced chemical vapor deposition technique exhibiting superior electrochemical performance. Systematically optimized as grown nanocrystalline silicon shows better electrical conductivity of 35 S cm−1. As anode for lithium-ion storage, nanocrystalline silicon exhibits initial discharge capacity of 3090 mAh g−1 at C/5 rate and retains around 2250 mAh g−1 after 50 cycles. Moreover, it displays high rate capability, viz., at 1C rate it delivers an initial discharge capacity of 1830 mAh g−1 with 70% capacity retention after 250 cycles. At 5C (21 A g−1) rate, discharge capacity greater than 650 mAh g−1 with good cycling stability (65% capacity retention) for 500 cycles. The enhanced capacity retention and high rate performance is attribute to unique nanoarchitecture where silicon nanocrystallites are entrench in amorphous silicon matrix. Besides, phosphorous doping improves the electronic conductivity while restricting the volume change by limiting lithium reactivity and phase transition. Hence, n-type silicon thin film comprising highly conducting nanocrystalline islands embed in amorphous silicon matrix is suitable for high power Li-ion battery applications.

Self-assembling Co3O4 Nanorods Electrode with High-Performance Anode for Lithium-Ion Batteries and Efficient Electrocatalysts Toward Oxygen Evolution Reaction

The mesoporous Co3O4 nanorods were fabricated on a nickel foam conductive substrate following a facile general strategy of hydrothermal technique; then thermally annealed. The self-growth property without additives, the porous structure of Co3O4 nanorods observed from transmission electron microscopy, and the pore size distribution account for their exceptional electrochemical performances. As the anode for lithium-ion storage, the Co3O4 nanorods electrode exhibits prominent battery behaviors with high specific capacity, superior rate capability and excellent cycle life. To be specific, a high discharge capacity of 611 mAh g−1 will be retained after 70 cycles at a current density of 300 mA g−1. Besides, a discharge capacity up to 848 mAh g−1 even at 100 mA g−1 can be kept. Water oxidation electrocatalysts based on Co3O4 nanorods electrodes also exhibit a low overpotential of 383 mV at 10 mA cm−2 for oxygen evolution reaction (OER) under long stability of 100,000 s. The present study confirmed a mesoporous Co3O4 nanorods electrode as a superb candidate for a high-performance anode in lithium storage and OER activity.

Fluorine-Enriched Graphdiyne as an Efficient Anode in Lithium-Ion Capacitors.

Lithium-ion capacitors (LICs) have shown extraordinary promise for electrochemical energy storage but are usually limited to electrodes with low energy density or power density owing to the lack of active storage sites and ion diffusion limitation. In this study, fluorine-enriched graphdiyne (F-GDY) is prepared by a solvothermal reaction. Owing to the 42-C hexagonal porous structure, abundant sp and sp2 hybrid carbon atoms, and even distribution of fluorine, F-GDY has enormous potential as an anode for lithium-ion storage. The outstanding rate performance (1825.9 mAh g-1 at 0.1 A g-1 , 979.2 mAh g-1 at 5 A g-1 ) and stable cycling stability of F-GDY in the lithium-ion battery inspire the assembly of a LIC with F-GDY as an anode and activated carbon (AC) as a cathode. When the AC/F-GDY mass ratio is 7:1, the LIC gives the largest energy density of 200.2 Wh kg-1 , corresponding to a power density of 131.17 W kg-1 . This LIC also shows excellent long-term cycling stability with a retention of approximately 80 % after 5000 cycles at 2 A g-1 and a retention of more than 80 % after 6000 cycles at 5 A g-1 .

Hierarchically porous carbon-coated SnO2@graphene foams as anodes for lithium ion storage

Graphene-based hierarchically porous materials have exhibited enormous potentials in high-performance lithium-ion batteries. However, the electrochemical performance of these materials is hampered due to the detachment of active materials from graphene upon long-term cycling. Therefore, the interfacial design between active materials and graphene is crucial for their high performance in lithium-ion storage. In this study, a hierarchically porous architecture of spatially confining carbon-coated SnO2 nanospheres (C-SnO2 NSs) within graphene foam has been designed and fabricated by employing the H-bonding effect of sodium carboxymethyl cellulose to bridge the C-SnO2 NSs and graphene sheets in a complete encapsulation arrangement. The as-fabricated architecture not only prevents the detachment of C-SnO2 from graphene and direct exposure of them in electrolyte, but also suppresses the electrode's pulverization caused by the large volume change of SnO2 during charge/discharge processes, thus achieving SnO2 interfacial and structural stability. Moreover, benefiting from the hierarchical porosity and interconnected graphene network, electrode reaction kinetics is greatly enhanced. As a result of these merits, the as-built electrode shows extraordinary rate capability (611.1 mA h g−1 at 4.0 A g−1; 427.9 mA h g−1 at 8.0 A g−1) and robust cycling stability (1458.8 mA h g−1 remaining after 700 cycles at 1.0 A g−1).