Binder-free Electrodes For Lithium-ion Batteries Research Articles

NiCo2O4 Nanofiber Cluster Assisted by NH4F Growing on 3D Graphene as a Binder-Free Electrode for Lithium-Ion Batteries

NiCo₂O₄ Nanofiber Cluster Assisted by NH₄F Growing on 3D Graphene as a Binder-Free Electrode for Lithium-Ion Batteries

Novel self-supporting multilevel-3D porous NiO nanowires with metal-organic gel coating via “like dissolves like” to trigger high-performance binder-free lithium-ion batteries

In this work, we put forward a concept of novel self-supporting multilevel-3D porous NiO nanowires and successfully synthesize them to be used as binder-free electrode for lithium-ion batteries (LIBs). According to the “like dissolves like” rule, Zr-based metal-organic gel (Zr-MOG) with the same organic ligand of the precursor of NiO is in situ coated on the surface of novel multilevel-3D porous nanowires, which not only effectively stabilizes the multilevel-3D porous network structure, but also adheres the electrode material to the surface of the Cu foil effectively and prevents electrode pulverization or shedding due to its own viscosity without adding binder (PVDF) in the process of fabricating electrode. Contact angle analysis illustrates Zr-MOG possesses potential to provide cementation power. Through theoretical simulation, the binding energy of NiO@Zr-MOG is lower than NiO, demonstrating the superiority to occur the redox reaction. The novel self-supporting multilevel-3D porous NiO nanowires coated by Zr-MOG possess superior electrochemical performance of LIBs (the specific capacity reached 1816.3 mAh g −1 at the current density of 100 mA g −1 , remained at 1318.7 mAh g −1 after 150 cycles). This work will provide a new perspective for the fabrication of high-performance binder-free LIB electrodes. • Put forward the concept of novel multilevel-3D porous nanowires. • Binder-free lithium-ion battery anode by “like dissolves like” coating. • The superiority of NiO@Zr-MOG was demonstrated by theoretical simulation. • The fabrication method is applicable to other transition metal oxides.

Significantly enhanced lithium storage by in situ grown CoS2@MoS2 core–shell nanorods anchored on carbon cloth

MoS 2 becomes one of the ideal anode materials for lithium-ion batteries (LIBs) because of its unique two-dimensional layered structure and high theoretical capacity. However, the poor conductivity and volume change during reaction hinder its application. In this work, we demonstrate a two-step hydrothermal method to synthesis the unique structure of core–shell CoS 2 @MoS 2 nanorods anchored on carbon cloth (CC). The one-dimensional Co(OH) 2 nanowire array on CC forms a carbon-based framework, which increases the reaction surface area for subsequent in situ generation of MoS 2 . The MoS 2 layer with rich holes enhances lithium storage capacity and increases the active sites. Compared with pure MoS 2 electrode, CoS 2 @MoS 2 /CC (CMCC) exhibits a stronger electrochemical performance as a binder-free electrode for LIBs. The structure has a high discharge specific capacity of 1175 mA h g −1 at the current density of 0.1 A g −1 . The further experiments prove that the CMCC structure has outstanding ion transport ability and low impedance characteristics, which are attributed to its special structure and the introduction of Co ions. The present work provides a new idea for the design of stable flexible electrode with high electrochemical performance for lithium-ion batteries. • The core–shell structure grown in situ is formed by constructing a precursor template. • The core–shell structure is synthesized by one-step hydrothermal method, which effectively improves the reaction rate. • The porous structure on the surface effectively prevents the accumulation of MoS 2 . • The synergistic effect of the structure significantly improves the electrical properties and stability of the material.

Embedded ZnO nanoparticles in N-doped carbon nanoplate arrays grown on N-doped carbon paper as low-cost and lightweight electrodes for high-performance lithium storage

Traditional slurry-based electrodes consist of heavy current collectors and electroactive materials with a low weight percentage, which inevitably increase the total weight and cost of lithium-ion batteries (LIBs). Consequently, the development of low-cost, lightweight, flexible and binder-free electrodes for LIBs is highly desirable but also greatly challenging. In this work, we report the synthesis of small ZnO nanoparticles uniformly embedded in N-doped carbon (NC) nanoplate arrays (NPAs) tightly grown on a N-doped carbon paper (NCP) substrate (ZnO/NC NPAs@NCP) through a facile metal-organic framework-engaged strategy. This electrode design not only avoids the utilisation of insulating polymer binders but also offers other advantages, including large electrode/electrolyte contact areas, abundant electroactive sites, good wettability of the electrolyte, fast electron/ion transport and efficient volume accommodation. Notably, the freestanding ZnO/NC NPAs@NCP electrode displays a high reversible capacity of 610 mA h g−1 (based on the mass of entire electrode) at a current density of 100 mA g−1 for 50 cycles and excellent long-term cycling stability (363 mA h g−1 at 500 mA g−1 for 200 cycles). Furthermore, a full cell employing ZnO/NC NPAs@NCP as the anode and commercial LiFePO4 as the cathode is constructed, indicating the feasibility for practical application. Moreover, an analysis of the electrode kinetics confirms the favourable lithium-ion storage kinetics within the ZnO/NC NPAs@NCP electrode. The present work could provide a new approach to develop low-cost, lightweight and flexible electrodes for advanced energy storage.

Binder-free layered ZnO@Ni microspheres as advanced anode materials for lithium-ion batteries

The advanced electrode construction consisting of Ni foam uniformly covered by layered ZnO microspheres (ZnO@Ni LMs) is successfully assembled by a simple thermal treatment process followed by a mild annealing treatment, which can be directly used as a binder-free electrode for lithium-ion batteries (LIBs). The as-synthesized ZnO@Ni LMs consist of numerous nanoparticles, leaving abundant porous to mitigate the volume changes between charge-discharge process. Remarkably, binder-free electrode circumvents the addition of insulating material (binder) and inhomogeneous distribution of conductive carbon material on current collector. When evaluated as binder-free electrode for LIBs, ZnO@Ni LMs deliver a superior specific capacity (1144 mA h g−1 at 100 mA g−1), brilliant rate capability, and excellent cycling ability (565 mA h g−1 at 100 mA g−1 after 100 cycles).

MCo2O4 (M=Co, Mn, Ni, Zn) nanosheet arrays constructed by two-dimension metal-organic frameworks as binder-free electrodes for lithium-ion batteries

Metal-organic frameworks (MOFs) derived ternary transition metal oxides have attracted more attention because of their unique features of large specific surface area, high porosity, and tunable morphology. Herein, we report a synthesis route for constructing porous MOF-derived MCo2O4 (M = Co, Mn, Ni, Zn) arrays directly on the Ni foam. Among them, MnCo2O4 nanosheet arrays electrode shows a higher capacity of 848 mAh g−1 at 0.2 A g−1. Further, MnCo2O4 electrode shows a good rate capability of 544 mAh g−1 at 2 A g−1. The MnCo2O4 electrode exhibits such good electrochemical performance primarily due to the unique nanostructure, composition of electrodes, and direct growth on the conductive substrates.

Metal-organic framework derived porous ternary ZnCo2O4 nanoplate arrays grown on carbon cloth as binder-free electrodes for lithium-ion batteries

Metal-organic frameworks (MOFs) derived ternary transition metal oxide nanostructures have attracted considerable attention for their important applications in energy-related fields. However, most of the present reports on MOFs-derived materials are in the powder form, which should be further mixed with polymer binder and conductive agents before they are coated on current conductor. In this work, we demonstrate a facile solution method to grow the bimetallic zinc/cobalt zeolitic imidazolate frameworks nanoplate arrays (Zn/Co-ZIF NPAs) on carbon cloth (CC) substrate and then they are well converted to porous ternary ZnCo2O4 NPAs on CC after an annealing treatment in air. When investigated as binder-free electrodes for lithium-ion batteries (LIBs), the ZnCo2O4 NPAs/CC electrode exhibits a high area capacity of 3.01 mA h cm−2 (corresponding to 1341.7 mA h g−1 for the ZnCo2O4 NPAs) at the current density of 0.24 mA cm−2 for 100 cycles, which is much higher than that of the Co3O4 NPAs/CC electrode (1.93 mA h cm−2). Moreover, at a high current density of 1.20 mA cm−2, the ZnCo2O4 NPAs/CC electrode can still maintain a high capacity of 2.05 mA h cm−2. The excellent electrochemical performance could be attributed to the unique morphology, structure and composition of the porous ternary ZnCo2O4 NPAs, as well as directly grown on current collector.

Reduced graphene oxide wrapped ZnMn2O4/carbon nanofibers for long-life lithium-ion batteries

ZnMn2O4 is regarded as one of the potential anode materials for lithium-ion batteries (LIBs), due to its high theoretical specific capacity (784 mAh g−1). Unfortunately, the bulk ZnMn2O4 presents an inferior electrochemical performance resulting from the large volume change during the charge-discharge process. In this paper, we report the synthesis and electrochemical properties of ZnMn2O4 nanoparticles (NPs) that are homogeneously distributed in connective network porous carbon nanofibers wrapped by reduced graphene oxide sheets. The distinctive structure of this composite not only provides enough voids to storage Li-ions and buffer the volume expansion of the ZnMn2O4 NPs, but also offers a continuous conducting network for Li-ion and electron transportation, resulting in significantly improved electrochemical performances. As binder-free electrodes for LIBs, an optimized ZnMn2O4@rGO-CNFs sample exhibits a reversible capacity of 1142 mAh g−1 at 100 mA g−1 over 100 cycles, and a stable capacity of 659 mAh g−1 after 1000 cycles at a large current density of 2000 mA g−1, enabling ZnMn2O4 a promising electrode candidate for LIBs.

CuO Nanorod Arrays Formed Directly on Cu Foil from MOFs as Superior Binder-Free Anode Material for Lithium-Ion Batteries

In this study, an in situ growth method is developed for the partial conversion of current collector into active materials for lithium ion batteries (LIBs). Through thermal treatment of a metal–organic framework (MOF) precursor, of which the metal ion is provided by a Cu foil current collector, porous CuO nanorod arrays (NRAs) can be directly formed on Cu foil. Importantly, this strategy can avoid the poor contact problem between the current collector and electrode material as well as circumvent the addition of insulating material (binder) and inhomogeneous distribution of conductive carbon material and active material on the current collector. When evaluated as binder-free electrodes for LIBs, porous CuO NRAs deliver a high specific capacity (1341 mA h g–1 at 100 mA g–1) and enhanced rate capability and cycling ability (671 mA h g–1 at 100 mA g–1 after 150 cycles).

Heat-induced formation of porous and free-standing MoS2/GS hybrid electrodes for binder-free and ultralong-life lithium ion batteries

Flexible and free-standing MoS2/GS films are constructed for the first time based on a novel heat-induced formation process, during which self-generated gaseous species successfully trigger the formation of porous structure, without the assistance of any templates or spacers. Graphene forms an open porous network, with few-layered MoS2 uniformly grown on the surface of GS. The fascinating structure provides several attractive features as anode material, including efficient ion transport, high conductivity and good structure durability. When used as free-standing and binder-free electrodes for lithium-ion batteries, the optimized hybrid film with graphene content of 32% exhibits superior rate capability (994, 880, and 598mAhg−1 at 0.5, 1, and 5Ag−1, respectively) and outstanding cycling performance at high rates (retaining 100.6% of the initial capacity after 1000 cycles at 1000mAg−1). Importantly, the electrochemical reaction kinetics and interfacial behavior of the hybrid electrode are also in-depth investigated by EIS and morphological study. The work described here can be extended to prepare various porous graphene-based hybrid films, for the application in a broad range of LIBs, electrochemical capacitors, sensors, and catalysts.

Growth of SnO2nanosheet arrays on various conductive substrates as integrated electrodes for lithium-ion batteries

A facile template-free solution method combined with a post annealing treatment is successfully developed to grow interconnected SnO2 nanosheets on various conductive substrates. Moreover, a second layer of SnO2 nanosheets can be grown on top of the first layer by simply repeating the procedure. When tested as integrated binder-free electrodes for lithium-ion batteries (LIBs), the electrodes deliver reasonably high specific capacity, excellent cycling stability and good rate capability.