Higher Lithium Ion Diffusion Research Articles

Li1.5Al0.5Zr1.5(PO4)3-coated Li1.2Mn0.54Ni0.13Co0.13O2 cathode materials with high lithium-ion diffusion rate and long cycling stability for lithium-ion batteries

Li1.5Al0.5Zr1.5(PO4)3-coated Li1.2Mn0.54Ni0.13Co0.13O2 cathode materials with high lithium-ion diffusion rate and long cycling stability for lithium-ion batteries

Optimization of LiNiCoMnO2 Cathode Material Synthesis Using Polyvinyl Alcohol Solution Method for Improved Lithium-Ion Batteries.

The growing need for lithium-ion batteries, fueled by the widespread use of electric vehicles (EVs) and portable electronic devices, requires high energy density and safety. The cathode material Li1-x(NiyCozMn1-y-z)O2 (NCM) shows promise, but attaining high efficiency necessitates optimization of both composition and manufacturing methods. Polycrystalline LiNiCoMnO2 powders were synthesized and assessed in this investigation using a polyvinyl alcohol (PVA) solution method. The study examined different synthesis conditions, such as the PVA to metal ions ratio and the molecular weight of PVA, to assess their influence on powder characteristics. Electrochemical analysis indicated that cathode materials synthesized with a relatively high quantity of PVA with a molecular weight of 98,000 exhibited the highest discharge capacity of 170.34 mAh/g and a high lithium-ion diffusion coefficient of 1.19 × 10-9 cm2/s. Moreover, decreasing the PVA content, irrespective of its molecular weight, led to the production of powders with reduced surface areas and increased pore sizes. The adjustments of PVA during synthesis resulted in pre-sintering observed during the synthesis process, which had an impact on the long-term stability of batteries. The electrodes produced from the synthesized powders had a positive impact on the insertion and extraction of Li+ ions, thereby improving the electrochemical performance of the batteries. This study reveals that cathode materials synthesized with a high quantity of PVA with a molecular weight of 98,000 exhibited the highest discharge capacity of 170.34 mAh/g and a high lithium-ion diffusion coefficient of 1.19 × 10-9 cm2/s. The findings underscore the significance of optimizing methods for synthesizing PVA-based materials to enhance the electrochemical properties of NCM cathode materials, contributing to the advancement of lithium-ion battery technology. The findings underscore the significance of optimizing methods for synthesizing PVA-based materials and their influence on the electrochemical properties of NCM cathode materials. This contributes to the continuous progress in lithium-ion battery technology.

Electrospun Co-Ni mixed multiple oxidation states heterostructure for high-performance Li-ion battery

With the increasing prevalence of mobile electronic devices, electric vehicles, and other technological advancements, there is a growing demand for higher-capacity Lithium-ion batteries (LIBs). Metal-organic frameworks (MOFs) have been actively researched in recent years due to their numerous advantages. However, the irreversible collapse during lithium-ion interaction hampers MOFs’ electrochemical stability. This study employs a direct precipitation method to synthesize uniformly shaped MOF materials, followed by carbon coating using electrospinning techniques, and ultimately, derivatives of MOF materials are produced through annealing. Thanks to this innovative material design process, exceptional performance is observed in this material as a lithium-negative electrode. After 1000 cycles at a high current density of 1 A g−1, its reversible capacity stabilizes at 1318 mAh g−1. Moreover, this negative electrode material exhibits exceptional rate performance at various current densities. The Co3O4/NiO@NCNFs electrode demonstrates enhanced charge storage capacity due to the synergistic effects of diffusion and capacitance control processes. Additionally, this material exhibits characteristics of low impedance and high lithium-ion diffusion rate. This study presents a novel method for manufacturing lithium-ion battery negative electrode materials by integrating MOF materials with electrospinning technology.

Novel LiFePO4/very-few-layer-graphene (LFP/VFLG) composites to improve structural and electrochemical properties of lithium-ion battery cathode

LiFePO4/Very-few-layer-graphene (LFP/VFLG) composites have been prepared using the sol-gel method for lithium-ion battery cathode. VFLG dominated by 1∼3 layers was obtained from an economical and environmentally benign process. Structural properties of LFP/VFLG composites were studied using Fourier-transform infrared spectra (FTIR) spectroscopy, X-ray diffractometry (XRD), high-resolution transmission electron microscopy (HRTEM) and Raman spectroscopy, while the electrochemical performance was measured using galvanostatic discharge, cyclic voltammetry (CV), and electrochemical impedance spectroscopy (EIS) tests. The FTIR analysis confirmed that incorporating VFLG neither affected the chemical structure of LiFePO4 nor initiated any side reactions during the LiFePO4 formation reaction. The XRD results showed that LFP/VFLG composites had better lattice parameters, crystallinity, and phase purity than LiFePO4 without VFLG addition. The Raman spectroscopy analysis indicated that LFP/VFLG composites had a lower disorder in the carbon arrangement. HRTEM results indicated that a VFLG was successfully wrapped around the LFP particle offers a versatile way to enhanced electrochemical performance of LFP/VFLG composites. The galvanostatic discharge profiles showed an enhancing specific discharge capacity of up to 58.3% after incorporating VFLG. The cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) tests revealed that LFP/VFLG delivered small polarization, low inner resistance, high electrochemical reaction reversibility, and high lithium-ion diffusion coefficient. VFLG is a promising additive to improve the structural and electrochemical properties of the LiFePO4 cathode of lithium-ion batteries.

Interfacial polymerization achieved integration of pore size adjustment, electrostatic repulsion and physical adsorption into one to inhibit polysulfide shuttle for enhanced lithium–sulfur battery

The application of lithium-sulfur battery is seriously hindered by the shuttle of dissolved polysulfide between sulfur cathode and lithium anode, by which is not selectively inhibited by the conventional separator. Developing functional separator is considered as a preferred solution for this issue, but it is always challenged by the tedious preparation process. Herein, interfacial polymerization (IP) is employed to modify the surface property of ZrO2 nanoparticles embedded polyetherimide (PZ) based separator, and the integration of pore size adjustment, electrostatic repulsion and physical adsorption into one is facilely achieved to effectively inhibit the polysulfide shuttle. Consequently, the optimized PZ separator presents a high lithium-ion transference number (0.55) and diffusion coefficient (2.16 × 10−8 cm s−1). Compared with the pristine one, the electrochemical performance of the assembled lithium-sulfur battery is obviously enhanced, and an initial discharge specific capacity of 1242 mAh g−1 and a capacity retention of 68 % after 200 cycles are obtained.

Binder-free germanium nanoparticle decorated multi-wall carbon nanotube anodes prepared via two-step electrophoretic deposition for high capacity Li-ion batteries.

Germanium (Ge) has a high theoretical specific capacity (1384 mA h g-1) and fast lithium-ion diffusivity, which makes it an attractive anode material for lithium-ion batteries (LIBs). However, large volume changes during lithiation can lead to poor capacity retention and rate capability. Here, electrophoretic deposition (EPD) is used as a facile strategy to prepare Ge nanoparticle carbon-nanotube (Ge/CNT) electrodes. The Ge and CNT mass ratio in the Ge/CNT nanocomposites can be controlled by varying the deposition time, voltage, and concentration of the Ge NP dispersion in the EPD process. The optimized Ge/CNT nanocomposite exhibited long-term cyclic stability, with a capacity of 819 mA h g-1 after 1000 cycles at C/5 and a reversible capacity of 686 mA h g-1 after 350 cycles (with a minuscule capacity loss of 0.07% per cycle) at 1C. The Ge/CNT nanocomposite electrodes delivered dramatically improved cycling stability compared to control Ge nanoparticles. This can be attributed to the synergistic effects of implanting Ge into a 3D interconnected CNT network which acts as a buffer layer to accommodate the volume expansion of Ge NPs during lithiation/delithiation, limiting cracking and/or crumbling, to retain the integrity of the Ge/CNT nanocomposite electrodes.

A 2D montmorillonite-carbon nanotube interconnected porous network that prevents polysulfide shuttling

A commercial polypropylene (PP) separator was modified by a one-dimensional carbon nanotube (CNT) and two-dimensional montmorillonite (MMT) hybrid material (CNT-MMT). Because of the high electron conductivity of the CNTs, and the strong polysulfide (LiPS) adsorption ability and easy lithium ion transport through MMT, the interconnected porous CNT-MMT interlayer with excellent structural integrity strongly suppresses LiPS shuttling while maintaining high lithium-ion transport, producing a high utilization of the active sulfur. Lithium-sulfur batteries assembled with this interlayer have a high lithium-ion diffusion coefficient, a high discharge capacity and stable cycling performance. They had an initial specific capacity of 1 373 mAh g−1 at 0.1 C, and a stable cycling performance with a low decay rate of 0.062% per cycle at 1 C after 500 cycles.

Application of two-dimensional lamellar lithium titanate in lithium-ion anode batteries

Lithium titanate exhibits effective suppression of lithium metal plating and lithium dendrite formation, attributed to its high lithium ion diffusion coefficient and a relatively high discharge plateau of 1.55 V (vs. Li+/Li). It is considered a zero-strain material, displaying minimal lattice size changes during lithium intercalation and deintercalation processes. The focus of this study was to obtain titanium dioxide through the calcination of selected MXene (Ti2C), and then mix it with lithium carbonate in a specific lithium-titanium ratio to generate lithium titanate. Spinel lithium titanate synthesized via solid-state method retained the sheet-like structure and excellent conductivity characteristics of MXene. Because its sheet structure provides a larger specific surface area for the electrode and enhances ion migration, it shows excellent electrochemical performance. The reaction mechanism was studied by in-situ Raman and variable speed CV. It was found that the reaction mechanism was pseudocapacitance plus lithium ion deintercalation. The obtained structure exhibited excellent electrochemical performance, making it suitable for applications in lithium-ion batteries.

Co-Ni Bimetallic Sulfides Functionalized Interlayer with Efficient Catalytic Conversion for Li-S Batteries

Tardive practical development of lithium-sulfur (Li-S) batteries faces two fatal nuisances, the grievous shuttle effect of sulfur electrodes as well as rock-ribbed Li dendrites, which results in undesired cycling lifespan and the potential safety hazard. Diversified electrocatalytic materials are employed to enhance polysulfides conversion kinetics and subsequently restrain shuttle effect. Here, pyrite-type cation regulation strategy is applied to motivate the electrochemical catalysis capability of bimetallic sulfide by regulating the cation ratio of Co and Ni ions. The reformative bimetallic sulfide with Co to Ni ratio near 2:1 shows stronger chemical adsorption capability towards lithium polysulfides in contrast to pristine NiS₂, which resulted from the strong contribution of metal oxide layer. The comparable electrochemical kinetics and electrochemical performances of Li-S batteries with CNS-2/CP interlayer show in the aspects of low polarization voltage, high lithium ion diffusion rate, high discharge capacity, as well as better rate performances. These results demonstrate cation regulation could be an efficient strategy for material design to optimize the surface physicochemical properties of iron pyrite for boosting the cycle durability of Li-S batteries.

Electrochemically Stable Rechargeable Lithium-Sulfur Batteries Equipped with an Electrospun Polyacrylonitrile Nanofiber Film.

The high theoretical charge-storage capacity and energy density of lithium-sulfur batteries make them a promising next-generation energy-storage system. However, liquid polysulfides are highly soluble in the electrolytes used in lithium-sulfur batteries, which results in irreversible loss of their active materials and rapid capacity degradation. In this study, we adopt the widely applied electrospinning method to fabricate an electrospun polyacrylonitrile film containing non-nanoporous fibers bearing continuous electrolyte tunnels and demonstrate that this serves as an effective separator in lithium-sulfur batteries. This polyacrylonitrile film exhibits high mechanical strength and supports a stable lithium stripping and plating reaction that persists for 1000 h, thereby protecting a lithium-metal electrode. The polyacrylonitrile film also enables a polysulfide cathode to attain high sulfur loadings (4-16 mg cm-2) and superior performance from C/20 to 1C with a long cycle life (200 cycles). The high reaction capability and stability of the polysulfide cathode result from the high polysulfide retention and smooth lithium-ion diffusion of the polyacrylonitrile film, which endows the lithium-sulfur cells with high areal capacities (7.0-8.6 mA·h cm-2) and energy densities (14.7-18.1 mW·h cm-2).

Improvement of electrochemical properties of lithium iron phosphate cathode by rare earth oxides modification

LiFePO4 cathode material has sluggish Li-ion diffusivity, which largely depends on surface modification to accelerate its slow kinetic process. Metal oxides, such as Al2O3, are promising coating materials to improve the capacity retention of the cathode materials in lithium-ion batteries, but their improvement on the diffusion rate of Li-ion is limited. In order to obtain the lithium iron phosphate cathode material with excellent rate and cyclic stability, this paper uses the advantages of La2O3 which has both good stability and low lithium ion diffusion barrier to prepare LiFePO4/C@La2O3 by a simple and easy operation method. The cathode of LiFePO4/C@La2O3 shows high lithium ion diffusivity of 1.4982 × 10−13 and decreased interface impedance by calculating the Li+ diffusion coefficient and measuring conductivity. Furthermore, the LiFePO4/C@La2O3 exhibits excellent rate capacibility (126 mAh g−1 at 10 C within 2.4–4.2 V) and long-cycle stability (96.5% capacity retention at 1 C after 500 cycles). These results indicate that further research on these oxide coating materials can enlarge the applicability of these materials.

A Ga-based liquid metal nanoparticles anode with carbon-coating layers for lithium-ion batteries

Ga-based liquid metal has been reported as a self-healing anode for lithium-ion batteries due to their good fluidity and surface tension. However, the materials still face the challenge of poor long-term stability due to mutual fusion and volume expansion. In this work, the pristine liquid metal nanoparticles (LMNPs) are prepared by the ultrasonic stirring method. And then polydopamine-coated LMNPs (LMNPs@PDA) is obtained by the polymerization of dopamine. Finally, the carbon-coated LMNPs (LMNPs@C) are obtained by annealing under an Ar atmosphere. The carbon layer can efficiently alleviate the volume effect and prevent the mutual fusion of LMNPs@C maintaining its high specific surface area and capacity. The LMNPs@C anode achieves the initial capacity of 959.9 mAh g−1 and a discharge capacity of 452.1 mAh g−1 at 0.2 A g−1 after 100 cycles. Besides, under the current density of 5 A g−1, the LMNPs@C anode still maintains the discharge capacity of 185 mAh g−1. Moreover, the LMNPs@C anode maintains a low Rct and a high lithium-ion diffusion coefficient due to the carbon layer equipping good conductivity.

Progressive Damage Analysis for Spherical Electrode Particles with Different Protective Structures for a Lithium-Ion Battery.

Charge-discharge in a lithium-ion battery may produce electrochemical adverse reactions in electrodes as well as electrolytes and induce local inhomogeneous deformation and even mechanical fracture. An electrode may be a solid core-shell structure, hollow core-shell structure, or multilayer structure and should maintain good performance in lithium-ion transport and structural stability in charge-discharge cycles. However, the balance between lithium-ion transport and fracture prevention in charge-discharge cycles is still an open issue. This study proposes a novel binding protective structure for lithium-ion battery and compares its performance during charge-discharge cycles with unprotective structure, core-shell structure and hollow structure. First, both solid and hollow core-shell structures are reviewed, and their analytical solutions of radial and hoop stresses are derived. Then, a novel binding protective structure is proposed to well-balance lithium-ionic permeability and structural stability. Third, the pros and cons of the performance at the outer structure are investigated. Both analytical and numerical results show that the binding protective structure serves with great fracture-proof effectiveness and high lithium-ion diffusion rate. It has better ion permeability than solid core-shell structure but worse structural stability than shell structure. A stress surge is observed at the binding interface with an order of magnitude usually higher than that of the core-shell structure. The radial tensile stress at interface may more easily induce interfacial debonding than superficial fracture.

In Situ Polymerized 1,3-Dioxolane Electrolyte for Integrated Solid-State Lithium Batteries.

Solid-state lithium batteries are promising and safe energy storage devices for mobile electronics and electric vehicles. In this work, we report a facile in situ polymerization of 1,3-dioxolane electrolytes to fabricate integrated solid-state lithium batteries. The in situ polymerization and formation of solid-state dioxolane electrolytes on interconnected carbon nanotubes (CNTs) and active materials is the key to realizing a high-performance battery with excellent interfacial contact among CNTs, active materials and electrolytes. Therefore, the electrodes could be tightly integrated into batteries through the CNTs and electrolyte. Electrons/ions enable full access to active materials in the whole electrode. Electrodes with a low resistance of 4.5 Ω □-1 and high lithium-ion diffusion efficiency of 2.5×10-11 cm2 s-1 can significantly improve the electrochemical kinetics. Subsequently, the batteries demonstrated high energy density, amazing charge/discharge rate and long cycle life.

Green aqueous binder poly(N-vinylformamide) for high-rate capability Li4Ti5O12 anode in lithium-ion batteries

To persue sustainable developments, poly (N-vinylformamide) (PNVF) is investigated as a green, bio-derived and water-soluble binder for Li4Ti5O12 (LTO) anode in lithium-ion batteries (LIBs). Electrochemical performance differences between PNVF electrodes and the conventional polyvinylidene fluoride (PVDF) electrodes are presented. The electrodes are characterized by peeling test, the galvanostatic charge/discharge cycle test, electrochemical impedance analysis (EIS), cyclic voltammetry (CV) and scanning electron microscope (SEM). The electrode with 3 wt% PNVF shows higher peeling force than the one with 10 wt% PVDF. The electrodes with 3 wt% PNVF and 10 wt% PVDF exhibit similar rate capability, whereas the capacity retention at 1C-rate is 91.2% (144 mAh/g) and 76.1% (123 mAh/g) after 1000 cycles, respectively. EIS and CV results exhibit that the lithium-titanium oxide (LTO) electrode with optimal PNVF binder (3 wt%) shows lower RSEI and Rct values as compared to that with PVDF counterpart and optimal PNVF electrode exhibits high lithium-ion diffusion coefficient. To enhance the cyclability and high-rate performance, vinylene carbonate (VC) is added as an electrolyte additive afterwards, and the results improve accordingly. Therefore, the results present in this paper demonstrated that PNVF is a potential aqueous binder for LTO anode within green fabrication.

Camphene-derived hollow and porous nanofibers decorated with hollow NiO nanospheres and graphitic carbon as anodes for efficient lithium-ion storage

A synthesis strategy for hollow and porous nanofibers comprising hollow NiO (H-NiO) nanospheres formed via nanoscale Kirkendall diffusion and supported over a porous graphitic carbon matrix (H-NiO@HNFs) is reported herein to enable the fabrication of advanced anodes for stable lithium-ion batteries (LIBs). The H-NiO@HNFs comprising 1D longitudinal hollow channels ensured efficient diffusion of charged species via effective electrolyte percolation besides providing sufficient space to accommodate the large volume variations during repeated cycling. The hollow NiO nanospheres acted as chemical sites for lithiation and delithiation. Additionally, the H-NiO@HNFs exhibited improved lithium-ion storage properties, such as reasonable rate capability, stable prolonged cyclability at a high current density (1.0 A g-1), and a high lithium-ion diffusion coefficient, primarily owing to their enhanced structural integrity compared to that of filled NiO nanofibers (F-NiO NFs). This facile synthesis approach could broaden the current understanding of 1D hollow nanostructures decorated with conventional hollow metal-oxide nanoparticles for various applications.

Boosting Lithium Storage of a Metal-Organic Framework via Zinc Doping.

Lithium-ion batteries (LIBs) as a predominant power source are widely used in large-scale energy storage fields. For the next-generation energy storage LIBs, it is primary to seek the high capacity and long lifespan electrode materials. Nickel and purified terephthalic acid-based MOF (Ni-PTA) with a series amounts of zinc dopant (0, 20, 50%) are successfully synthesized in this work and evaluated as anode materials for lithium-ion batteries. Among them, the 20% atom fraction Zn-doped Ni-PTA (Zn0.2-Ni-PTA) exhibits a high specific capacity of 921.4 mA h g−1 and 739.6 mA h g−1 at different current densities of 100 and 500 mA g−1 after 100 cycles. The optimized electrochemical performance of Zn0.2-Ni-PTA can be attributed to its low charge transfer resistance and high lithium-ion diffusion rate resulting from expanded interplanar spacing after moderate Zn doping. Moreover, a full cell is fabricated based on the LiFePO4 cathode and as-prepared MOF. The Zn0.2-Ni-PTA shows a reversible specific capacity of 97.9 mA h g−1 with 86.1% capacity retention (0.5 C) after 100 cycles, demonstrating the superior electrochemical performance of Zn0.2-Ni-PTA anode as a promising candidate for practical lithium-ion batteries.

Tailoring of a reinforcing and artificial self-assembled alkyl sulfonic acid layer electrolyte interphase on silicon as an anode for high-energy-density lithium-ion batteries

Making anodes from silicon results in various longstanding challenges, including drastic volume expansion, formation of a thick and high-impedance solid electrolyte interphase (SEI), rapid capacity decay, and poor rate performance. The use of these anodes in high-energy-density lithium-ion batteries is thus limited. Herein, an artificial SEI with a self-assembled alkyl sulfonic acid (SAASA) reinforcement structure is deposited onto the surface of Si through an organosilane approach (to obtain a Si-SAASA electrode). A coupling agent, 3-mercaptopropyl trimethoxysilane (MPTMS), was tailored on the surface of Si to produce strong siloxane (Si–O–Si) bonds. The thiol group (-SH) in the MPTMS molecule consequently oxidized into sulfonic acid (-SO3H), resulting in sulfonated artificial SEI reinforcement on the Si surface. With sulfonated MPTMS, the Si anode was improved through the formation of -SO3Li, which enhanced Li+-ion diffusion and ionic mobility. The Si-SAASA electrode has the highest discharge capacity of 1507.1 mAh g−1 at 0.5 C after 400 cycles with a retention capacity of 74.3%, high rate capability, and a high lithium-ion diffusion coefficient (2.88 × 10−12 cm2 s−1). This study demonstrated that the SAASA reinforcement, acting as an artificial SEI, gives the electrode mechanical integrity, meaning that during cycling, expansion of the Si's volume can be accommodated and the fragmentation of Si particles can be prevented through the strong siloxane bonds. Additionally, the SAASA serves as a protection against parasitic reactions between the electrolyte and active interface, thus preventing the repeated growth of a thick and high-impedance SEI layer. The developed approach will be exceedingly effective and minimize the cost of developing high-performance Si anodes for next-generation lithium-ion batteries.

Lithium ion sieve modified three-dimensional graphene electrode for selective extraction of lithium by capacitive deionization

Faced with the strong demand of clean energy, development of lithium source is becoming exceedingly vital. Spinel-type manganese oxide (λ-MnO2) is a typical lithium ion sieve material. Herein, the conductive three-dimensional (3D) lithium ion sieve electrode material was fabricated by in-situ growth of λ-MnO2 on 3D reduced graphene oxide (3D-rGO) matrix for Li extraction by capacitive deionization (CDI). The λ-MnO2 modified rGO (λ-MnO2/rGO) retained the 3D network structure with uniform distribution of λ-MnO2 nanosheets on rGO. Electrochemical characterization demonstrated its high conductivity and fast lithium ion diffusion rate. By adjusting the rGO concentration, λ-MnO2 activity was improved significantly. With λ-MnO2/rGO as a positive electrode (activated carbon as negative electrode), the corresponding CDI system was successfully applied for the selective extraction of Li+. The final rGO content in the λ-MnO2/rGO was attained by thermogravity analysis. With the appropriate rGO content (15.5%), the obtained λ-MnO2/rGO electrode achieved the optimal Li+ adsorption amount. The corresponding λ-MnO2/rGO-based CDI cell showed good selectivity and high cycle stability. When applied to the extraction of lithium from synthetic salt lake brine, the electrode also obtained high Li+ adsorption amount with good selectivity.

The Synergetic Effect Induced High Electrochemical Performance of CuO/Cu2O/Cu Nanocomposites as Lithium-Ion Battery Anodes.

Due to the high theoretical capability, copper-based oxides were widely investigated. A facile water bath method was used to synthesis CuO nanowires and CuO/Cu2O/Cu nanocomposites. Owing to the synergetic effect, the CuO/Cu2O/Cu nanocomposites exhibit superior electrochemical performance compared to the CuO nanowires. The initial discharge and charge capacities are 2,660.4 mAh/g and 2,107.8 mAh/g, and the reversible capacity is 1,265.7 mAh/g after 200 cycles at 200 mA/g. Moreover, the reversible capacity is 1,180 mAh/g at 800 mA/g and 1,750 mAh/g when back to 100 mA/g, indicating the excellent rate capability. The CuO/Cu2O/Cu nanocomposites also exhibit relatively high electric conductivity and lithium-ion diffusion coefficient, especially after cycling. For the energy storage mechanism, the capacitive controlled mechanism is predominance at the high scan rates, which is consistent with the excellent rate capability. The outstanding electrochemical performance of the CuO/Cu2O/Cu nanocomposites indicates the potential application of copper-based oxides nanomaterials in future lithium-ion batteries.