Anode Electrode For Lithium-ion Batteries Research Articles

Low-cost porous silicon material based on fenton process assisted chemical etching and its application as anode for lithium-ion battery

Nanostructured silicon-based materials are considered as one of the most promising alternatives for anode electrodes of lithium-ion batteries. Nevertheless, the relatively high cost and complexity of most present processes make them difficult to scale up. In this manuscript, we would like to introduce a porous anode prepared by Fenton reaction-assisted chemical etching of low-cost ferrosilicon in the mixed solution of hydrogen fluoride and hydrogen peroxide. The experimental results show that hierarchical structures containing both mesopores and micropores can be formed by this convenient room-temperature etching process and its electrochemical performance as the anode is comparable to that of commercial product. Furthermore, the low cost of ferrosilicon ($1200~1500/ton) compared with the silicon powder of industrial grade (~$3000/ton) traditionally used in Li-ion battery anode preparation also renders this method potential and feasible for large-scale production of Si-based anode materials.

Constructing novel deep eutectic composites based on hydrogen bond network as anode material for lithium-ion batteries

The replacement of metallic materials with non-metallic materials as anode electrodes for lithium-ion batteries (LIBs) is an increasing hot spot for constructing a new generation of energy storage field. Here, a novel deep eutectic composites material consisting of quaternary ammonium salts (QASs) and N-methyl pyrrolidone (NMP) on the basis of hydrogen bonding reaction is used as the anode material of LIBs, boasting numerous advantages, including facile synthesis, environmental friendliness, superb conductivity, self-healing property, and multiple active sites to provide capacity. Typically, tetraethylammonium chloride (TEACl)/NMP delivered a reversible specific capacity of 764.8 mAh/g at 100 mA/g after cycling 420 times and coulombic efficiency is maintained near 100 % after 1000 cycles at 100 mA/g. The availability of hydrogen bonding network reduces the lattice energy of its components and creates defects, which is more favorable for the intercalation reaction in LIBs. Concurrently, the effect of hydrogen bonding reaction and the natural mobility of the deep eutectic composites exhibit high self-healing properties, facilitating the repair of the reaction interface in real time. An abundance of active sites that can bind Li+ to form LiH is used to provide capacity, which is also confirmed by density functional theory (DFT) method.

Synthesized Fe-doped Co3O4 nanoparticles-based anode for high-performance lithium-ion batteries application

ABSTRACT Co3O4 has been considered a promising anode material because of its high theoretical capacity (890 mAh/g) and remarkable energy density. Unfortunately, it suffers from low initial coulombic efficiency, rapid capacity fading, poor electronic conductivity, large volume changes, and aggregation during the lithium ion intercalation/deintercalation process. In this work, a series of Fe2+-doped Co3O4 nanostructured materials Co3(1-x)Fe3xO4 (x = 0, 0.01, 0.02 and 0.03) were produced by a simple chemical co-precipitation method. The Fe doping led to a slight increase of the lattice parameter, which is beneficial to the rapid diffusion of Li+ ion during the lithiation/delithiation process. Meanwhile, the Fe-doped Co3O4 sample exhibited an excellent rate capability of 886.47 mAh/g at 500 mA/g, and outstanding cyclic stability (1156.91 mAh/g for 50 cycles, with the capacity retention rate of 83.53% at the current density of 100 mA/g), demonstrating improved electrochemical performance, compared with that of pure Co3O4. The good electrochemical performance profited from the formation of oxygen vacancies by Fe doping, which provided more space for Li+ diffusion and improved the electronic conductivity of the anode material. This work provides a simple way to improve the comprehensive electrochemical performance of the transitional metal oxide Co3O4 anode electrodes for lithium-ion batteries.

Development of a roll-to-roll high-speed laser micro processing machine for preparing through-holed anodes and cathodes of lithium-ion batteries

Aiming to improve the battery performance of lithium-ion batteries (LIBs), modification of the cathodes and anodes of LIBs using laser beams to prepare through-holes, non-through-holes or ditches arranged in grid and line patterns has been proposed by many researchers and engineers. In this study, a laser processing system attached to rollers, which realizes this modification without large changes in the present mass-production system, was developed. The laser system apparatus comprises roll-to-roll equipment and laser equipment. The roll-to-roll equipment mainly consists of a hollow cylinder with openings on its circumferential surface. Cathode and anode electrodes for LIBs are wound around the cylinder in the longitudinal direction of the electrodes. A pulsed beam reflected from the central axis of the cylinder can continuously open a large number of through-holes in the thin electrodes. Through-holes were formed at a rate of 100 000 holes per second on lithium iron phosphate cathodes and graphite anodes with this system. The through-holed cathodes and anodes prepared with this system exhibited higher C-rate performance than nontreated cathodes and anodes.

Hard Carbons Derived from Phenyl Hyper-Crosslinked Polymers for Lithium-Ion Batteries

Hyper-crosslinked polymers are attracting extensive attention owing to their ease of design and synthesis. Based on the flexibility of its molecular design, a hyper-crosslinked polymer with a π-conjugated structure and its derived carbon were synthesized by the Friedel–Crafts reaction. The polymer and its derived hard carbon material were characterized by FTIR, 13C NMR, Raman, BET, and other characterization tools. The electrochemical properties of both materials as anode electrodes of lithium-ion batteries were investigated. Benefiting from the highly cross-linked skeleton and conjugated structure, the as-prepared carbon materials still had high specific surface area (583 m2 g−1) and porosity (0.378 cm3 g−1) values. The hard carbon (CHCPB) anode possessed the powerful reversible capacity of 699 mAh g−1 at 0.1A g−1, and it had an excellent rate of performance of 165 mAh g−1 at the large current density of 5.0 A g−1. Long-cycle performance for 2000 charge/discharge cycles displayed that the capacity was kept at 148 mAh g−1 under 2 A g−1. This work contributes to a better understanding of the properties of hard carbon materials derived from hyper-crosslinked polymers and how this class of materials can be further exploited in various applications.

Enhanced lithium storage capacitance of layered CoFe2O4&V2CT hybrid anode material synthesized by in-situ hydrothermal method

CoFe 2 O 4 &V 2 CT x hybrid material was synthesized as a high volumetric performance anode in lithium-ion batteries by an in-situ hydrothermal method. Multilayered V 2 CT x in the hybrid acts as a superior host for homogenous loading CoFe 2 O 4 nanoparticles due to the opened two-dimensional structure of MXene, favorable electrical conductivity and low Li + diffusion barrier. XRD results confirmed CoFe 2 O 4 &V 2 CT x hybrid had been formed, and SEM images showed the spherical CoFe 2 O 4 nanoparticles were randomly deposited on the surface of accordion-like morphology MXene. Being an anode material, it exhibited a good reversible capacity of 638.6 mAh g −1 with 97.8 % coulombic efficiency after 100 cycles at 1 C. In addition, ex-situ X-ray photoelectron spectra revealed that a redox reaction was involved in the Li + ions extraction/insertion process. Our work provides further insight into the hybrid application of the binary metal & layered MXene hybrids as high-performance anode electrodes for lithium-ion batteries. Scheme 1. The graphical abstract. • CFO&V 2 CT x hybrid material were prepared the by in-situ hydrothermal method. • CFO&V 2 CT x hybrid exhibited a reversible capacity of 638.6 mAh g −1 after 100 cycles at 1 C. • Ex-situ XPS revealed a redox reaction was involved in the Li + ions extraction/insertion process.

Nanoparticles constructed mesoporous coral-like Mn2O3 as high performance anode for lithium-ion batteries

As well established, the morphology and architecture of electrode materials greatly contribute to the electrochemical properties. Herein, a novel structure of mesoporous coral-like manganese (III) oxide (Mn2O3) is synthesized via a facile solvothermal method coupled with the carbonization under air. When fabricated as anode electrode for lithium-ion batteries (LIBs), the as-prepared Mn2O3 exhibits good electrochemical properties, showing a high discharge capacity of 1090.4 mAh g−1 at 0.1 A g−1, and excellent rate performance of 410.4 mAh g−1 at 2 A g−1. Furthermore, it maintains the reversible discharge capacity of 1045 mAh g−1 at 0.1 A g−1 after 380 cycles, and 755 mAh g−1 at 1 A g−1 after 450 cycles. The durable cycling stability and outstanding rate performance can be attributed to its unique 3D mesoporous structure, which is favorable for increasing active area and shortening Li+ diffusion distance.

Electrochemical properties of C/SiO2 prepared from rice husks with LiPF6 and LiClO4 salts as electrolytes

The C/SiO2 materials were prepared from rice husks used as anode electrodes for Lithium-ion batteries. The XRD results show that the diffraction peak had a large half-width and the material existed in an amorphous form. The first peak at the position 20o - 27o (2θ), was characterized by amorphous silica and amorphous carbon and the second peak at the position 43o - 44o was characterized by amorphous carbon. The C/SiO2 material contained 28.1 wt% SiO2. The scanning electron microscopy (SEM) and transmission electron microscopy (TEM) images observed on the surface of the material showed many holes with sizes of 100 - 400 nm, the porosity was also formed inside the material structure with a size of a few nm. The C/SiO2 materials were investigated for their electrochemical properties in some types of the electrolyte of LiPF6 and LiClO4 salts and in some mixture the solvents used were EC:DMC (1:1), EC:DEC(1:1) and EC :DMC:DEC (1:1:1). The electrochemical results showed that the LiClO4 EC:DMC (1:1) electrolyte had the highest capacity, about 1,700 mAh.g-1 at 0.1 Ag-1 rate in the potential range of 0.01 - 2V. In addition, the material maintained a good capacity while increasing to higher current rates and the coulombic efficiency were more stable compared to other electrolytes. The results of the Electrochemical Impedance Spectroscopy (EIS) also showed that the impedance of this electrolyte system was about 20 Ω, therefor the processes of interlocking and releasing Li+ ions were more favorable than the other studied electrolyte.

Copper foil after hydrothermal treatment in acidified tungstate solution as conductor- and binder-Free anode electrodes for high performance lithium-ion batteries

Copper foil is commonly used as anode current collector in the battery industry due to its high conductivity, good elasticity and relative abundance. Herein, copper foil was hydrothermally treated in acidified tungstate solution, resulting in the formation of Cu2O and WO3 agglomerated clusters on the copper foil substrate with sufficient open space between neighboring clusters. The copper foil after hydrothermal treatment was directly used as the conductor- and binder-free anode electrode for lithium-ion batteries. Cyclic voltammetry and charge-discharge measurements were performed to investigate the reversible areal capacity, cycling stability and rate capability of the as-prepared electrode. A reversible areal capacity of 357 μAh cm−2 was obtained after 50 cycles at a current density of 60 μA cm−2. Even cycled at a current density of 600 μA cm−2, a reversible capacity of 8 μAh cm−2 remained. When the current density returns to 60 μA cm−2, the conductor- and binder-free electrode exhibits an areal discharge capacity of 430 μAh cm−2.

Hetero-Element-Doped Molybdenum Oxide Materials for Energy Storage Systems.

In order to meet the growing demand for the electronics market, many new materials have been studied to replace traditional electrode materials for energy storage systems. Molybdenum oxide materials are electrode materials with higher theoretical capacity than graphene, which was originally used as anode electrodes for lithium-ion batteries. In subsequent studies, they have a wider application in the field of energy storage, such as being used as cathodes or anodes for other ion batteries (sodium-ion batteries, potassium-ion batteries, etc.), and electrode materials for supercapacitors. However, molybdenum oxide materials have serious volume expansion concerns and irreversible capacity dropping during the cycles. To solve these problems, doping with different elements has become a suitable option, being an effective method that can change the crystal structure of the materials and improve the performances. Therefore, there are many research studies on metal element doping or non-metal doping molybdenum oxides. This paper summarizes the recent research on the application of hetero-element-doped molybdenum oxides in the field of energy storage, and it also provides some brief analysis and insights.

Valorisation of banana peel waste as a precursor material for different renewable energy systems

The following different valorisation processes of banana peel waste (BPW) were evaluated: combustion, production of activated carbon/batteries, and biomethanisation. This study showed that the combustion of BPW is an interesting option with a zero-carbon cycle. A mass balance demonstrated a low concentration of sulphurous compounds in the flue gases (0.01%, in volume), but the content of structural nitrogen dioxide was remarkable (0.35%). Additionally, BPW should be pre-dried to increase its lower calorific value (LCV) upto 3000 kcal/kg. In contrast, the mesophilic biomethanisation of BPW led to the generation of renewable methane (182 LCH4/kg VS, volatile solids) and organic digestate, whereas its biodegradability was found to be 68% under the study conditions. The obtention of porous activated carbon was also demonstrated by employing a simple and low-cost method based on chemical activation/carbonisation of BPW with KOH porogen. The banana peel waste carbon (BPW–C) obtained showed low crystallinity, high purity, and Brunauer-Emmett-Teller surface area (SBET) of 264 m2/g. BPW-C was tested as an anode electrode in lithium-ion batteries (LIBs), and a remarkable reversible capacity of 225 mAh/g at 0.2 C after 200 cycles was observed. These results indicate the feasibility of the carbonisation method of BPW to produce a highly demanded product in the current society.

Bio-Derived Porous Carbon from Agar as an Anode Material for Lithium-Ion Batteries

In past decades, environmental concerns and fossil fuel depletion have spurred the development of green and renewable technologies that can efficiently convert and store energy sources. In particular, lithium-ion batteries (LIBs) have been gaining increasing attention due to their high reversible capacity, outstanding rate performance and cycling stability as well as portability and low pollution. However, the commercially available LIBs with graphite anode cannot meet the ever-increasing demand for high energy density devices, therefore, the exploring of an alternative anode is essential to enhance the energy storage capacity of LIBs. Recently, biomass-derived carbon materials have shown excellent electrochemical performance as a negative electrode, making them an ideal candidate as a new host material for lithium ions.Here we propose a one-pot, low-cost, and environmentally friendly synthesis method of a bio-derived porous carbon with a high surface area as an anode electrode for LIBs. Four chemical activators such as H2SO4, H3PO4, KOH, and ZnCl2 have been investigated as a facilitator to the formation of the porous structure of activated carbon (AC) from the agar precursor. Among the used chemical activators, AC prepared with the addition of KOH demonstrated the best electrochemical performance in a reaction with lithium metal. The initial discharge capacity reached 931 mAh g-1 and a reversible capacity of 320 mAh g-1 was maintained over 100 cycles at 0.1C. The high rate performance up to 10 C demonstrated stable cycling performance of AC from agar. Keywords: activated carbon; agar; anode; lithium-ion battery, chemical activators.Acknowledgments:This work was supported by the project 091019CRP2114 “Three-Dimensional All Solid State Rechargeable Batteries” from Nazarbayev University. Graphical abstract Disordered carbonaceous materials synthesized from an environmentally sustainable agar precursor and their electrochemical characteristics as the anode for LIBs. Figure 1

Hollow N,C-co-doped carbon-coated ZnS nanospheres derived from metal organic framework (ZIF-8) with improved lithium and sodium storage performance

Transition metal sulfides have been widely used as anode electrodes of lithium-ion batteries (LIBs) and sodium-ion batteries (SIBs) due to its high theoretical capacity and low price. However, problems of huge volume expansion and poor conductivity during charging and discharging have been emerged. Herein, we design a N, C-co-doped, nano-sized, and hollow carbon-coated ZnS (ZnS-NC@C) composite using the advantages of metal organic framework (zeolitic imidazolate framework-8) structure and resorcinol-formaldehyde coating. When applied as anodes of LIBs and SIBs, it displays a high reversible capacity of 748 and 150.9 mAh g−1 after 500 cycles at the current density of 1.0 A g−1, respectively. This work could provide a promising strategy for enhancing the performance of transition metal sulfides for potential applications in LIBs and SIBs.

Simulation and optimization of silicon/carbon core-shell structures in lithium-ion batteries based on electrochemical-mechanical coupling model

Silicon is considered as a first candidate for ideal anode material of the next-generation lithium-ion battery due to its high theoretical capacity to meet the demand for higher energy density. On the other hand, high theoretical capacity is accompanied by massive volume expansion, which gives arise to high stress and crack and pulverization of anode particles. Finally, the capacity of the battery fades gradually. While some kinds of factors contribute to the failure of silicon-based electrodes, the most important one is the diffusion-induced stress generated in silicon-based electrode particles. The cyclic processes of lithiation and delithiation are accomplished by the intercalation into and deintercalation from the silicon particles of lithium ions. During the cycle, physical processes and chemical processes, such as diffusion of lithium ions, phase transition, and volume expansion, take place simultaneously, making the cyclic process a strong-coupling problem to be addressed. For example, the intercalation of lithium ions into the electrode results in volume expansion and phase transition of anodes, thereby inducing stress; in turn, stress affects the diffusion process of lithium ions. Aiming to probe this problem, with the finite deformation hypothesis, an electrochemical-mechanical coupling model is used to study the variation and distribution of concentration and stress of core-shell structure during lithiation. And more importantly, great emphasis is put on the optimal design of core-shell structure. The numerical results show that the shell is useful in prohibiting the volume expansion of silicon core, but large compressive radial stress in silicon core may cause the core and shell to be detached, while the tangential tensile stress at the core-shell interface leads the shell to fracture. To improve the electrochemical and mechanical performance and hence lengthen the cycle life of lithium-ion batteries, two kinds of optimal designs are considered: 1) single-layered core-shell structure and 2) double-layered core-shell structure. The numerical results suggest that the softer shell material is suitable for a single-layered core-shell structure and the inner-soft & outer-hard design is optimal for the double-layered core-shell structure. Furthermore, the effects of Young's modulus of the inner and outer carbon layer materials on the chemical and mechanical performance of anode are explored. The simulation shows that the optimal Young's modulus of the inner shell is less than 10 GPa, and that of the outer shell is not higher than 70 GPa. This research is helpful in designing and optimizing the silicon-based anode electrodes of lithium-ion batteries.

Integrate electrical conductivity and Li+ ion mobility into hierarchical heterostructure Ti3C2@CoO/ZnO composites toward high-performance lithium ion storage

The structural instability and low electrical conductivity of CoO and ZnO cause their rapid capacity fading when it is used for lithium ion storage, which limits their applications. In response, a hierarchical heterostructure was formed by anchoring CoO/ZnO nanodots onto the surface of Ti3C2 to effectively address the above issue. Ti3C2 has an excellent electrochemical performance which can effectively enhance the electrical conductivity of CoO/ZnO and facilitate lithium ion mobility, and CoO/ZnO nanodots that are uniformly anchored on the Ti3C2 surface can effectively inhibit the aggregation of CoO/ZnO nanodots during cycling. As an anode electrode for lithium-ion batteries, the Ti3C2@CoO/ZnO electrode exhibits a high reversible capacity (1069 mA h g−1 at 0.2 A g−1 for over 120 cycles), excellent cycleability (1052 mA h g−1 at 0.5 A g−1 for over 200 cycles, and 627 mA h g−1 at 1 A g−1 for over 300 cycles) and exceptional rate capacity (498 mA h g−1 at 3 A g−1, and holds 794.3 mA h g−1 after 110 cycles when the current is controlled at 0.1 A g−1 again). This work paves the way for the structural modification of other types of metal oxides (sulfides) to enhance electrochemical performance.

Simple Approach: Heat Treatment to Improve the Electrochemical Performance of Commonly Used Anode Electrodes for Lithium-Ion Batteries.

The lithium-ion battery (LIB) industry has been in high demand for simple and effective methods to improve the electrochemical performance of LIBs. Here, we treated three different widely studied anode electrodes (i.e., Li4Ti5O12, TiO2, and graphite) under vacuum at 250 °C, and compared their electrochemical performance with and without a 250 °C treatment. Without changing the composition of the fabricated electrodes, all of the 250 °C treated electrodes exhibited enhanced specific capacities, and the lithium-ion diffusion was improved in different degrees. By comparing the results of scanning electron microscopy (SEM) and energy-dispersive spectroscopy of the pristine and 250 °C treated electrodes, the 250 °C treatment improved the distribution of a polyvinylidene difluoride (PVDF) binder in the electrodes, resulting in a higher porosity of the 250 °C treated electrodes. The results of X-ray photoelectron spectrometry and SEM of the cycled electrodes confirmed that a uniform distribution of the PVDF binder from the 250 °C treatment played a positive role in the formation of a solid electrolyte interphase layer, thereby delivering higher capacities and capacity retentions than those of electrodes without heat treatment. The simplicity of this modification method provides considerable potential for building high-performance LIBs at a larger scale.

An enabling strategy for ultra-fast lithium storage derived from micro-flower-structured NiX (X=O, S, Se)

Transition metal oxides/sulfides/selenides (TMOSS), regarded as three of the most potential anode materials for lithium-ion batteries (LIBs), are superior to their low cost, controllable morphology and high theoretical capacity. Herein, a facile strategy, using Ni-MOF material as precursor, was designed to fabricate the unique micro-flower-like NiO, NiS/C and NiSe/C electrodes, including the detailed investigation about their electrochemical and kinetics properties. The results show that sizes of NiO, NiS/C and NiSe/C micro-flowers are around 0.7, 3.5 and 2.0 μm, respectively, which contains abundant micro- and meso-pores. Among them, NiSe/C material exhibits better electrochemical performance when used as anode electrode for LIBs, with high initial capacity (1688.4 mAh g−1 at 0.1 A g−1) and high reversible capacity (1016.5 mAh g−1 at 1.0 A g−1 after 1000 cycles). Moreover, the full-cell, NiSe/C vs. LiCoO2, exhibits superior reversible discharge capacities of 421.8 mAh g−1 at 0.1 A g−1 after 50 cycles. It is important that the bond energy of Ni–Se contributes to improving NiSe/C electrochemical performance. This work shows the influence of Li+ insertion and pseudocapacitance behavior on lithium storage performance of TMOSS anode materials, which provides an effective strategy for research and development of TMOSS on LIBs.

Theoretical analysis of borophene for lithium ion electrode

Borophene, a 2-dimensional material with efficacious properties (electrical, thermal and mechanical), is a very promising material that is expected to contribute, significantly, in the revolutionization of electrochemical energy storage, for improved energy and power density. In order to prove the potency of borophene as a potential anode electrode in lithium-ion batteries, density function theory simulation is performed. The study considered the interaction of stable striped, (β12), and honeycomb (Hb) borophene, with lithium ions. The main interest is to investigate the adsorption energy of the materials, and their specific capacities. The calculated average adsorption energies for the two promising electrodes are: −1.710 eV, and −0.517 eV. Moreover, the estimated specific capacities of the batteries, are: 929 mAh/g and 584 mAh/g; these results evidently proved that borophene may deliver the total energy demand of the globe, if more attention is paid into it, through dedicated research and development.

SnO2 Quantum Dots@Graphene Framework as a High-Performance Flexible Anode Electrode for Lithium-Ion Batteries.

Three-dimensional (3D) layered tin oxide quantum dots/graphene framework (SnO2 QDs@GF) were designed through anchoring SnO2 QD on the graphene surface under the hydrothermal reaction. SnO2 QDs@GF have a 3D skeleton with a large number of mesopores and ultrasmall SnO2 QDs with a large surface area. The unique design of this structure improves the specific area and promotes ion transport. The mechanically strong SnO2 QDs@GF can directly be used as the anode of lithium-ion batteries (LIBs); it displays a high reversible capacity (1300 mA h g-1 at 100 mA g-1), excellent rate performance (642 mA h g-1 at 2000 mA g-1), and superior cyclic stability (when the current density is 10 A g-1, the capacity loss is less than 2% after 5000 cycles). This novel synthetic method can further be expanded for the production of other quantum dots/graphene composites with a 3D structure as high-performance electrodes for LIBs.

Ionic liquid-derivatized hierarchical N-doped carbon-coated Co3O4 nanosheet array as high-performance anode materials for lithium-ion batteries

A novel nitrogen-doped carbon-coated graded Co3O4 nanosheets (NDC/Co3O4 NS) is synthesized by using a simple ionic liquid hydrothermal method. The as-prepared NDC/Co3O4 NS is composed of hexagonal nanosheets having different orientation and the thickness of 50–100 nm. Significantly, as an anode electrode for lithium-ion batteries (LIBs), the NDC/Co3O4 NS performed excellent cyclability. The NDC/Co3O4 NS delivers an initial discharge capacity of 1281.4 mAh g−1 at 445 mA g−1 and maintains a reversible high capacity of 929.4 mAh g−1 after 50 cycles, much higher than the unmodified Co3O4 nanosheets (230 mAh g−1). The superior excellent electrochemical performance can be attributed to the gradient structure and the nitrogen-doped carbon coating resulting in shorter ion transport distances and good electrical conductivity.