Binder-free Anode For Lithium-ion Batteries Research Articles

Synthesis of graphene quantum dots-coated hierarchical CuO microspheres composite for use as binder-free anode for lithium-ion batteries

There is an urgent need to develop improved anode materials for lithium-ion batteries (LIBs). Herein, we report the synthesis of a graphene quantum dots (GQDs)-coated hierarchical nanoflake-based CuO microspheres (H–CuO) composite on Cu foam via a one-pot hydrothermal technique for use as a binder-free anode for LIBs. The carboxyl-functionalized GQD coating on H–CuO not only results in lower charge-transfer resistance and enhanced electrical conductivity but also prevents the dissolution and agglomeration of the electrode. The GQDs/H–CuO composite anode exhibits a reversible capacity as high as 609 mAh g−1 (pristine H–CuO: 61 mAh g−1) after 200 cycles at 0.2 A g−1. It also shows long-term cycling stability, exhibiting a capacity retention rate of 79.4% after 1000 cycles (pristine H–CuO: 0.7%) at a high current density (2 A g−1) and improved initial coulombic efficiency at 88.2% (pristine H–CuO: 75.2%). The superior electrochemical properties of the GQDs/H–CuO composite anode are attributable to the graphene networks, which help maintain a high specific surface area and effectively protect the anodic active material from forming an unstable solid electrolyte interface layer. The proposed strategy for fabricating the GQD-coated metal oxide microsphere-based anode should contribute to the development of next-generation LIBs with improved electrochemical performance.

Pencil lead based low cost and binder-free anode for lithium-ion batteries: effect of different pencil grades on electrochemical performance

We depict a facile and one step approach to fabricate a high capacity anode by drawing pencil lead onto the current collector. For efficient loading and adhesion, stainless steel substrate used as a collector is roughened using sand paper before drawing the pencil lead onto it. As pencil lead comprises graphite-clay (primarily silica) composites, graphite provided cyclic stability due to lithium ion intercalation while SiO2 resulted in higher reversible capacity by facilitating alloying and de-alloying of lithium with silicon. To evaluate their role further onto the anodic performance, three different pencil grades (4H, 4B and 10B) are used which varied in graphite and silica composition. A detailed comparative analysis of their electrochemical performances is done and is further correlated to their structural parameters. Importantly, the fabrication of anode is not only facile but also is solvent and binder free and is also scalable for real application.Graphic Abstract

Hollow multi-nanochannel carbon nanofiber/MoS2 nanoflower composites as binder-free lithium-ion battery anodes with high capacity and ultralong-cycle life at large current density

The electrode materials with high pseudocapacitance can enhance the rate capability and cycling stability of lithium-ion storage devices. Herein, we fabricated MoS2 nanoflowers with ultra-large interlayer spacing on N-doped hollow multi- nanochannel carbon nanofibers (F2-MoS2/NHMCFs) as freestanding binder-free anodes for lithium-ion batteries (LIBs). The ultra-large interlayer spacing (0.78∼1.11 nm) of MoS2 nanoflowers can not only reduce the internal resistance, but also increase accessible active surface area, which ensures the fast Li+ intercalation and deintercalation. The NHMCFs with hollow and multi-nanochannel structure can accommodate the large internal strain and volume change during lithiation/delithiation process, it is beneficial to improving the cycling stability of LIBs. Benefiting from the above combined structure merits, the F2-MoS2/NHMCFs electrodes deliver a high rate capability 832 mA h g−1 at 10 A g−1 and ultralong cycling stability with 99.29 and 91.60 % capacity retention at 10 A g−1 after 1000 and 2000 cycles, respectively. It is one of the largest capacities and best cycling stability at 10 A g−1 ever reported to date, indicating the freestanding F2-MoS2/NHMCFs electrodes have potential applications in high power density LIBs.

Rational synthesis of silicon into polyimide-derived hollow electrospun carbon nanofibers for enhanced lithium storage

Abstract Flexible energy devices with high energy density and long cycle life are considered to be promising applications in portable electronics. In this study, silicon/carbon nanofiber (Si@CNF) core–shell electrode has been prepared by the coaxial electrospinning method. The precursors of polyimide (PI) were for the first time used to form the core–shell structure of Si@CNF, which depicts outstanding flexibility and mechanical strength. The effect of doping concentrations of silicon (Si) nanoparticles embedded in the fiber is investigated as a binder-free anode for lithium-ion batteries. A 15 wt% doped composite electrode demonstrates superior performance, with an initial reversible capacity of 621 mA h g−1 at the current density of 100 mA g−1 and a high capacity retention up to 200 cycles. The excellent cycling performance is mainly due to the carbonized PI core–shell structure, which not only can compensate for the insulation property of Si but also has the ability to buffer the volume expansion during the repeated charge–discharge process.

Rationally designed three-dimensional porous NiCo2N@C reticular structure for high-performance Li-ion batteries

Three-dimensional (3D) porous NiCo2N@C composite was deposited on nickel foam substrate through the electrostatic spray deposition (ESD) technique followed by a post-annealing process under ammonia atmosphere. The prepared reticular-structured NiCo2N@C film used as binder-free anode for lithium-ion batteries (LIBs) can exhibit excellent electrochemical performance. It delivers high initial discharge capacity of 1215.8 mAh g−1 at a current density of 1 A g−1 and can reach 1630.9 mAh g−1 after 400 cycles. The electrode also shows a superior rate capability with 955.4 mAh g−1 at 10 A g−1 current density.

Hierarchical Assembly of MoS2 Nanosheets on Macroporous Ti Mesh as a Binder-Free Anode for Lithium-Ion Battery

In this work, a MoS2-based binder-free electrode has been fabricated via a simple hydrothermal deposition approach. In this electrode, the MoS2 nanosheets are orderly assembled and immobilized on macroporous titanium (Ti) mesh with exposed active sites for Li-storage. The Ti mesh with a 3D porous network provides a stable skeleton and large surface area for loading MoS2 nanosheets. Meanwhile, the intimate contact with conductive Ti mesh facilitates fast charge transfer in the electrode reactions. When applied as an anode in lithium-ion battery, the binder-free electrode exhibits a greatly promoted Li-storage property, including desirable cycling durability and superior rate capability.

Low-temperature preparation of mesoporous TiO2 honeycomb-like structure on TiO2 nanotube arrays as binder-free anodes for lithium-ion batteries

TiO2 is a typical intercalated-type anode material for lithium-ion batteries (LIBs). TiO2 nanotube arrays (NTAs) were prepared by anodic oxidation method on Ti foils. Then treated with TiF4 solution at 60 °C for 4 h, anatase TiO2 honeycomb-like structure (HS) was uniformly distributed on the top of TiO2 NTAs. The thickness and diameter of the generated TiO2 HS are about 59 nm and 121–153 nm, respectively. Furthermore, the TiO2 HS has uniform mesopores (~ 3 nm), which can supply abundant Li-ion diffusion and transport channels. The as-prepared TiO2 NTAs/HS served as binder-free anodes of LIBs and exhibited high invertible specific capacities (290 mAh g−1, 0.1 A g−1 and 96 mAh g−1, 2 A g−1). The TiO2 NTAs/HS electrode also showed a good cycling stability with the specific capacity of 40 mAh g−1 after 1000 cycles at a current density of 1 A g−1. Hence, this low-temperature in situ preparation of mesoporous TiO2 HS is an effective way to improve the performance of TiO2 as anode for LIBs.

Lithium‐Ion Batteries: In Situ Growth of CoP3/Carbon Polyhedron/CoO/NF Nanoarrays as Binder‐Free Anode for Lithium‐Ion Batteries with Enhanced Specific Capacity (Small 11/2020)

In article number 1907468, Yingjie Du, Wei Ma, and Haibo Li propose a facile method to in-situ synthesize CoP3/carbon polyhedron/CoO/nickel foam nano-arrays as binder-free anode for lithium-ion batteries (LIBs). The superior specific capacity and rate capability of as-designed anode are explored and highlighted. This study will enrich the application of phosphorous-based material for LIBs with high energy and power densities.

Macroporous Cu(OH)2 nanorod network fabricated directly on Cu foil as binder-free Lithium-ion battery anode with ultrahigh capacity

Metal-hydroxide based materials have attracted much attention as electrode materials for electrochemical energy storage and conversion owing to their unique large interlayer spacing, enhanced active surface area and robustness that can result in high electrochemical performance. Here, we report on the synthesis of a macroporous Cu(OH)2 nanorod network via single-step surface chemical oxidation and demonstrate its impressive Li ion battery (LIB) performance as a binder-free anode material. The Cu(OH)2 nanorod network anode delivers an ultrahigh reversible discharge capacity of 2145 mAhg−1 at a current density of 0.1 Ag−1 in the first cycle that then stabilizes at 1472 mAhg−1 in the subsequent cycles. The excellent rate performance at the ultrahigh current rates of 1.0 and 2.0 Ag−1 with a Coulombic efficiency of 99% was obtained. The electrode exhibits the capacity of 506 mAhg−1 even after 100 cycles which is higher than the conventional carbonaceous materials. Our experimental findings and scalable synthesis approach can be useful for developing other free-standing binder-free transition metal hydroxide materials that can be directly used as battery electrodes and catalysts.

In Situ Growth of CoP3 /Carbon Polyhedron/CoO/NF Nanoarrays as Binder-Free Anode for Lithium-Ion Batteries with Enhanced Specific Capacity.

Advanced functional materials enable lithium-ion batteries to reach high specific capacity. To achieve this goal, nickel foam (NF), as current collector, is chosen to in situ form aligned nanoarrays composed of CoP3 /carbon polyhedron (CP)/CoO. The CoO nanowire acts as bridge to link NF and CoP3 /CP which not only reinforces the adhesion between active material and NF but also enhances the capacity of whole electrode. Besides, CoP3 is evenly coupled with CP, which can effectively buffer the volume expansion of CoP3 during the charge/discharge process. Moreover, the novel architecture of CoP3 /CP/CoO/NF is beneficial to improve the electronic conductivity. As a result, the CoP3 /CP/CoO/NF anode delivers an ultrahigh specific capacity of 1715 mAh g-1 at 0.5 A g-1 which can remain at 1150 mAh g-1 after 80 cycles, demonstrating the good durability. Thus, this work develops a facile strategy to design self-supporting electrodes for an enhanced energy storage device.

Hierarchical urchin-like Fe2O3 structures grown directly on Ti foils for binder-free lithium-ion batteries with fast charging/discharging properties

Hierarchical urchin-like Fe2O3 structures were grown on conductive Ti foil with robust adhesion via a facile two-step solvothermal method and subsequent annealing, and directly used as a binder-free lithium-ion battery anode Benefitting by the unique structural features, the resultant Fe2O3 hierarchical structures exhibited excellent electrochemical performance with remarkable specific capacities at a serious of current rates 1–5 A g−1 and good cycling stability for excellently reversible lithium storage. The enhanced electrochemical performance demonstrates their promise for use as integrated binder-free electrodes in lithium-ion batteries. Using this additive/binder-free electrode, a discharge capacity as high as 581.2 mAh g−1 at a current density of 5 A g−1 was achieved after 1000 cycles. Importantly, the facile and effective strategy developed in this study can be extended to other metal oxides for various applications.

Rationally Designed Three-Dimensional Porous Nico <sub>2</sub>n@C Reticular Structure for High-Performance Li-Ion Batteries

Three-dimensional (3D) porous NiCo2N@C composite was deposited on nickel foam substrate through the electrostatic spray deposition (ESD) technique followed by a post-annealing process under ammonia atmosphere. The prepared reticular-structured NiCo2N@C film used as binder-free anode for lithium-ion batteries (LIBs) can exhibit excellent electrochemical performance. It delivers high initial discharge capacity of 1215.8 mAh g-1 at a current density of 1 A g-1 and can maintain 1630.9 mAh g-1 after 400 cycles. The electrode also shows a superior rate capability with 955.4 mAh g-1 at 10 A g-1 current density.

An integrated electrode based on nanoflakes of MoS2 on carbon cloth for enhanced lithium storage

Due to its high specific capacity (in theory), molybdenum disulfide (MoS2) has been recognized as a plausible substitute in lithium-ion batteries (LIBs). However, it suffers from an inferior electric conductivity and a substantial volume change during Li+ insertion/extraction. By using a facile hydrothermal method, a flexible free-standing MoS2 electrode has here been fabricated onto a carbon cloth substrate. The grafting of ultrathin MoS2 nanoflakes onto the carbon cloth framework (forming CC@MoS2), was shown to facilitate an improved electron transport, as well as an enhanced Li+ transport. As expected, the as-obtained CC@MoS2 electrode was observed to exhibit an excellent lithium storage performance. It delivers a high discharge specific capacity of 2.42 mA h cm−2 at 0.7 mA cm−2 (even after 100 cycles), which is an impressive result.

Spherical vanadium phosphate particles grown on carbon fiber cloth as flexible anode for high-rate Li-ion batteries

Spherical vanadium phosphate (VPO4) particles grown on flexible electron-conductive carbon fiber cloth (CFC) is developed as a binder-free anode for lithium-ion batteries (LIBs). The flexible composite electrode (VP@CFC) exhibits an excellent performance, including high reversible lithium-ion storage capacity (541.2 mAh g−1 at 0.1C), high rate capability (350.2 mAh g−1 at 10C), and good cycling stability (a capacity retention ratio of 91.8% after 250 cycles at 1C). Moreover, a flexible full cell fabricated with the VP@CFC as anode and a commercial LiCoO2 (LCO) coated on CFC (LCO@CFC) as cathode displays good flexibility against mechanical bending at a wide range of angle while maintaining its good electrochemical performance. The flexible VP@CFC electrode holds a great promise in applications for flexible energy storage devices.

In Situ Precipitation-Induced Growth of Leaf-like CuO Nanostructures on Cu-Ni Alloys for Binder-Free Anodes in Li-Ion Batteries.

CuC2 O4 ⋅x H2 O was facilely prepared on a Cu-Ni alloy substrate by in situ precipitation-induced growth by using a mixture of sodium persulfate, hydrogen peroxide, and oxalic acid. Thermal annealing allowed the conversion of CuC2 O4 ⋅x H2 O to leaf-like CuO nanostructures with a thickness of a few tens of micrometers of sub-sized nanoparticles, which were applied for fabricating binder-free anodes for lithium-ion batteries. Ni was a nucleation site for CuC2 O4 ⋅x H2 O, which was uniformly formed on the entire substrate. The concentration of each component in the mixture solution caused significant morphological changes because of the different elution of copper ions. CuO nanostructures annealed at 550 °C showed large areal and gravimetric capacity with excellent capacity retention of 95.5 % after 200 cycles at a high current density because of their appropriate structural morphology, which not only allowed the formation of a stable solid electrolyte interphase layer but also enabled a reversible reaction during the charge/discharge process.

Three-dimensionally architectured tungsten trioxide/tungsten trioxide hydrate/carbon cloth composite as a binder-free anode for lithium-ion batteries

The exploration of suitable host structures as anodes is essential for lithium-ion batteries. In this work, a three-dimensionally architectured tungsten trioxide/tungsten trioxide hydrate/carbon cloth composite was synthesized by a simple and cost-effective hydrothermal process. The obtained tungsten trioxide/tungsten trioxide hydrate/carbon cloth composite was directly used as the binder-free electrode and evaluated as an anode for lithium-ion batteries by cyclic voltammetry, galvanostatic discharge-charge measurements, and electrochemical impedance spectroscopy. The binder-free electrode exhibits a high reversible lithium storage capacity of 825 mA h g−1 after 100 cycles at a current density of 0.1 A g−1. When cycled at a current density of 2 A g−1, a capacity of 309 mA h g−1 remained. The excellent electrochemical performance may be due to the unique self-assembled tungsten trioxide/tungsten trioxide hydrate nanorods on the carbon cloth conductive substrate with a three-dimensional architecture.

Centrifugally Spun α-Fe2O3/TiO2/Carbon Composite Fibers as Anode Materials for Lithium-Ion Batteries

We report results on the electrochemical performance of flexible and binder-free α-Fe2O3/TiO2/carbon composite fiber anodes for lithium-ion batteries (LIBs). The composite fibers were produced via centrifugal spinning and subsequent thermal processing. The fibers were prepared from a precursor solution containing PVP/iron (III) acetylacetonate/titanium (IV) butoxide/ethanol/acetic acid followed by oxidation at 200 °C in air and then carbonization at 550 °C under flowing argon. The morphology and structure of the composite fibers were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDS), X-ray photoelectron spectroscopy (XPS), and thermogravimetric analysis (TGA). These ternary composite fiber anodes showed an improved electrochemical performance compared to the pristine TiO2/C and α-Fe2O3/C composite fiber electrodes. The α-Fe2O3/TiO2/C composite fibers also showed a superior cycling performance with a specific capacity of 340 mAh g−1 after 100 cycles at a current density of 100 mA g−1, compared to 61 mAh g−1 and 121 mAh g−1 for TiO2/C and α-Fe2O3/C composite electrodes, respectively. The improved electrochemical performance and the simple processing of these metal oxide/carbon composite fibers make them promising candidates for the next generation and cost-effective flexible binder-free anodes for LIBs.

Pulsed electrophoretic deposition of nanographitic flake-nanostructured Co3O4 layers for efficient lithium-ion-battery anode

In spite of the high capacity of Co3O4 nanomaterial to employ in lithium-ion battery anodes, the reduced conductivity and significant volume change of Co3O4 during long cycling of insertion and extraction of Li ions remain a challenge. Utilization of composite materials making use of graphene-based materials together with Co3O4 nanostructures can offer a suitable strategy to address these challenges. Here, a composite material consisting of nanographitic flake and CO3O4 nanoparticles is synthesized by solvothermal reactions. After successive oxidation treatments, two types of electrophoretic deposition processes, namely, direct current and square wave pulse current are used to fabricate binder-free anodes for lithium-ion batteries. Compared to the direct current electrophoretic deposition technique, the pulsed electrophoretic deposition technique with a square wave is found to enhance the efficiency of the fabricated anode. The pulsed electrophoretic deposition technique enables the formation of the anode from smaller agglomerated Co3O4 nanoparticles compared to the anode obtained with the direct current electrophoretic deposition. The selective deposition of less agglomerated Co3O4 nanoparticles results in an excellent rate capability and durability of the anode fabricated by the pulsed electrophoretic deposition (a charge capacity of 780 mAh/g after 50 cycles at 1 A/g with total retention of 89%).

Carbon cloth–supported Fe2O3 derived from Prussian blue as self-standing anodes for high-performance lithium-ion batteries

The carbon cloth (CC)–supported Prussian blue (PB) composite was firstly prepared by using CC as the substrate and PB as active material through a solution impregnation method. Then, the Fe2O3/CC material was obtained by the subsequent high-temperature calcination of PB/CC. This is the first example of composites based on CC and PB (or PB analogues)-derived metal oxides. The resulting Fe2O3/CC composite can be employed directly as binder-free anodes for lithium-ion batteries (LIBs), exhibiting superior electrochemical performances to pure CC and Fe2O3. The mass specific capacity of Fe2O3/CC was about 395 mA h g−1 (an areal capacity of 5.1 mA h cm−2) at 100 mA g−1 with almost no decay after 135 discharge/charge cycles. The outstanding lithium storage properties of Fe2O3/CC benefit from the synergistic interaction between CC and Fe2O3.

Electrodeposited Silicon Nanowires from Silica Dissolved in Molten Salts as a Binder-Free Anode for Lithium-Ion Batteries

Rational manipulation of size, surface chemistry, and electrode configuration is of prime importance to enhance lithium storage capability of silicon-based anode for Li-ion batteries. Herein, Si na...