Electrodes For Lithium Storage Research Articles

In situ anchoring of FeNi nanoparticles into three-dimensional nitrogen-doped carbon framework as a self-supporting electrode for high-performance lithium storage

Constructing free-standing electrodes with superior lithium storage capacity and good mechanical performance are fascinating for next-generation lithium-ion batteries (LIBs). Nevertheless, their practical application is hindered by complicated synthesis procedures and high cost. Herein, a highly stable, self-supporting and flexible electrode material for LIBs was constructed by encapsulating spherical FeNi nanoparticles into one-dimensional N-doped carbon fiber film (FeNi/N- CFM) using the electrospinning technique and subsequent heat treatment. The FeNi/N-CFM can be directly used as anode materials for LIBs without conductive additive, current collector and binder. The synergistic effect of uniformly dispersed small FeNi nanoparticles and three-dimensional (3D) conductive network constructed by CF framework effectively improves the utilization rate of active materials, enhances the transport of both electrons and lithium ions, facilitates the electrolyte penetration, and promotes the lithium-ion storage kinetics and stability, thus leading to a greatly enhanced electrochemical performance. Benefiting from the unique architectural feature and flexibility, the FeNi/N-CFM composites employed as binder-free electrodes for LIBs exhibit good lithium storage performance (an initial discharge capacity of 1031.5 mA h g−1 and a reversible capacity of 481.3 mA h g−1 at 100 mA g−1 after 100 cycles), rate capacity (305.1 mA h g−1 at 1000 mA g−1) and outstanding reversibility (coulombic efficiency of around 100 % after 100 cycles). Furthermore, this work also provides a facile and effective pathway to design and fabricate free-standing electrodes.

A new FeS2/N-C nanoparticle from NH2-MIL-101 for high performance lithium ion batteries

Among multitudinous lithium storage electrode materials, transition metal sulfides have attracted widespread attention because of high theoretical capacity and wide availability. However, these anodes still suffer poor capacity retention and limited cycle life. Metal organic frameworks (MOFs) are important precursors for fabricating functional materials for energy conversion and storage. A study of their derivatization process is of great significance for the design of materials with specific functional properties. In this paper, a new FeS2/N-C nanoparticle is synthesized by calcination strategy from NH2-MIL-101 prepared by solvothermal method. Due to the coordination effect of nitrogen-doped carbon and special particle morphology, the synthesized FeS2/N-C nanoparticles have superior cycling stability and high reversible capacity. This work provides a better understanding of the carbonization process of MOFs and reveals the effect of N-doped and MOF synthesis time on transition metal sulfides.

Femtosecond laser fabrication of 3D vertically aligned micro-pore network on thick-film Li4Ti5O12 electrode for high-performance lithium storage

The development of energy storage devices with high energy density relies heavily on thick film electrodes, but it is challenging due to the limited ion transport kinetics inherent in thick electrodes. Here, we report on the preparation of a directional vertical array of micro-porous transport networks on LTO electrodes using a femtosecond laser processing strategy, enabling directional ion rapid transport and achieving good electrochemical performance in thick film electrodes. Various three-dimensional (3D) vertically aligned micro-pore networks are innovatively designed, and the structure, kinetics characteristics, and electrochemical performance of the prepared ion transport channels are analyzed and discussed by multiple characterization and testing methods. Furthermore, the rational mechanisms of electrode performance improvement are studied experimentally and simulated from two aspects of structural mechanics and transmission kinetics. The ion diffusion coefficient, rate performance at 60 C, and electrode interface area of the laser-optimized 60-15% micro-porous transport network electrodes increase by 25.2 times, 2.2 times, and 2.15 times, respectively than those of untreated electrodes. Therefore, the preparation of 3D micro-porous transport networks by femtosecond laser on ultra-thick electrodes is a feasible way to develop high-energy batteries. In addition, the unique micro-porous transport network structure can be widely extended to design and explore other high-performance energy materials.

Spherically Structured Ce‐Metal‐Organic Frameworks with Rough Surfaces and Carbon‐Coated Cerium Oxide as Potential Electrodes for Lithium Storage and Supercapacitors

AbstractThe rough spherical‐shaped cerium metal‐organic framework (Ce‐MOF) is synthesized by using solvothermal technique, and after being calcined at 550 °C both with and without tannic acid, CeO2 and C@CeO2 are produced. As synthesized Ce‐MOF, CeO2, and C@CeO2 are constructed as anodes for lithium‐ion batteries (LIBs), also Ce‐MOF and C@CeO2 are investigated for use in supercapacitors. In the case of LIBs, as anode, C@CeO2 exhibits a good reversible discharge capacity of 137 mAh g−1 with 99 % coulombic efficiency over 250 cycles at 1 C rate. It demonstrates that the conductivity is greatly improved by the carbon covering than the pristine CeO2 and Ce‐MOF. After the galvanostatic charge‐ discharge technique at 1 C rate, the morphology size was investigated using FESEM to conform further the following alloying and dealloying mechanism of C@CeO2 and the dissolution of terephthalic acid (TPA) in the non‐aqueous electrolyte that is connected to the core structure of Ce‐MOF. In terms of supercapacitors, rough surface morphology improves the electrode electrolyte conduct also the ligand TPA of free terminal acid group attracting K+ and forms the COO− K+. Thus, Ce‐MOF exhibits a good specific capacitance; after 5000 cycles, it produces 118 F g−1 at 4 A g−1.with 65.2 % capacitance retention. The archived maximum power and energy density outcomes of 10.6 kW kg−1 and 0.56 Wh kg−1 at 2 A g−1.

MoS2/C nanotubes synthesized using halloysite as template through one-pot hydrothermal method for Li-ion batteries

One-dimension MoS2/carbon (MoS2/C) with expended interlayer spacing of MoS2 has been proposed as a promising strategy to improve the electrochemical performance of MoS2 materials in lithium-ion batteries (LIBs). Surface etched or functionalized carbon nanotubes/fibers are usually used as carriers or hosts for MoS2/C in preparing 1 D MoS2/C materials. However, the widespread adoption is hindered by the expensive carbon nanotubes/fibers and the tedious preparation process. Herein, low-cost natural halloysite was introduced as a template in synthesizing MoS2/C nanotube (NT-MoS2/C) with expended interlayer spacing through one-pot hydrothermal method. The tubular structure, larger specific surface area (43.81 m2/g) and larger mesopore volume (0.16 cm3 g−1, Vmes/Vtotal = 72.45 %) of NT-MoS2/C have been obtained with halloysite as template compared to NP-MoS2/C (without using halloysite as template) and NC-H@MoS2/C (without removal of halloysite template). When used as lithium storage electrodes, the rate performance and cycling stability of NT-MoS2/C have been significantly improved over NP-MoS2/C and NC-H@MoS2/C by the constructed tubular structure. The lithium storage electrochemical performance of MoS2/C with expended interlayer spacing can be further improved by tubular structure constructed with natural halloysite as template. This strategy is expected to offer a pathway towards the scalable application of MoS2/C materials in next-generation LIBs technology.

3DG/Se4.7S3.3 composites with different morphologies as new all-solid-state lithium storage electrode materials

Selenium-sulfur(SexSy) composites can be used as energy storage materials for lithium batteries benefit from their integration of the high capacity of sulfur and the high conductivity of selenium. Herein, we prepared amorphous three dimensional reduced graphene oxide/selenium sulfide(a-3DG/Se4.7S3.3) composites and crystalline 3DG/Se4.7S3.3(c-3DG/Se4.7S3.3) composites by in situ synthesis and hydrothermal methods, respectively, in order to research the effect of different morphologies of 3DG/Se4.7S3.3 composites on the electrochemical properties of all-solid-state lithium batteries. Our study found that the a-3DG/Se4.7S3.3 cathodes displayed greater capacity and outstanding rate performance, with an initial discharge capacity of 926 mAh g−1 and utilization rate of 103% at 1/2C. And a first discharge capacity of up to 706 mAh g−1 at 7 C. Although the first discharge capacity of c-3DG/Se4.7S3.3 was 523 mAh g−1, its cycling stability was significantly improved compared with that of a-3DG/Se4.7S3.3 cathodes, and the Coulombic efficiency remained above 97% after 60 cycles at ½ C. In this work, we investigate the performance of solid-state batteries by preparing new SexSy composites with different morphologies and rational design of electrodes in terms of structure and morphology, which provides ideas for the preparation of electrodes in the future.

Tin-cobalt bimetals in 2D leaf-like MOF-derived carbon for advanced lithium storage applications

Tin-based (Sn) composite materials have exhibited a promising potential to substitute traditional graphite because of their appreciable specific capacity and improved safety. However, pure metallic Sn anode suffers from poor capacity retention in long-term cycling caused by large volumetric changes. Herein, a binary Sn-Co alloy was embedded in a carbon matrix derived from nitrogen-doped two-dimensional (2D) leaf-like metal-organic-framework (MOF) via a facile one-step approach. A uniform distribution of Sn-Co alloy particles was obtained. The generated 2D leaf-like carbon framework not only served as a conductive matrix to promote electronic conduction, but also acted as a buffer phase to relieve pulverization. As an electrode material, this composite showed a high specific capacity, favorable initial coulombic efficiency (ICE) of 65%, and superior rate performance even under high current density (10 C). In the long-term cycling test (700 cycles), it displayed an excellent reversible specific capacity of 604 mAh g−1 with no capacity reduction. These results demonstrated the expected advantages of the Sn-Co@C composite electrode for advanced lithium storage.

Fabrication of hierarchical flower-shaped cobalt silicate spheres with boosting performance for lithium storage

As a new type of electrode material, transition metal silicates anode has drawn increasing attention owing to high theoretical capacity, sufficient reserves and nontoxicity. Herein, a unique flower-shaped cobalt silicate was fabricated via an alkali-assisted hydrothermal synthesis method, which feathered large specific surface area and abundant meso-pores. Serving as an anode material for lithium ion batteries, the hierarchical CoSiO 2 material exhibited excellent cycling stability (1111 mAh g −1 at 0.1 A g −1 after 200 cycles) and superior rate capability (411 mAh g −1 at 10 A g −1 ). The novel structure of F–CoSiO 2 anode not only provided abundant active sites for electrochemical reactions and effectively facilitated the migration of Li ions during charge-discharge process, but also contributed to the primary pseudocapacitive charge storage behaviors. This work may open up opportunities in structure design and represent the enormous potential of hierarchical transition metal silicate as practical advanced electrode for lithium storage. • A novel flower-shaped CoSiO 2 anode material for lithium ion batteries was designed and fabricated firstly. • The 3D architecture assembled by 2D nanosheets generated large surface area and abundant mesopores. • The hierarchical structure greatly shortened mass diffusion and fascinated the transport of Li ions. • The CoSiO 2 material exhibited remarkable cycling and rate performance.

Fabrication of fall sunflower-like GeO2/C composite as high performance lithium storage electrode

Fabrication of fall sunflower-like GeO2/C composite as high performance lithium storage electrode

N-doped carbon coated SnO2 nanospheres as Li-ion battery anode with high capacity and good cycling stability

• Tin dioxide nanospheres coated with N-doped carbon film were developed. • It involves a sacrificial template method and a subsequent carbon coating process. • The NC@SnO 2 HNSs exhibit high stable capacity and high rate performance. • High Li storage performance is due to the hollow structure and carbon coating. The preparation of high electrochemical performance SnO 2 -based anode is a crucial promotion to be an alternative electrode for lithium storage. To this end, SnO 2 hollow nanospheres covered with nitrogen-doped carbon shell (denote as NC@SnO 2 HNSs) are designed and synthesized. The NC@SnO 2 HNS electrode could not only improves the conductivity of pure SnO 2 HNSs effectively, but also possesses a large proportion of the cavity (73.8 %), which could cope the strain relaxation. Benefiting from the superior structural design, the NC@SnO 2 HNS electrode exhibits high reversible capacity (868.6 mAh g −1 after 200 cycles at 0.2 A g −1 ), long-term cycling performance (360.6 mAh g −1 after 500 cycles at 1.0 A g −1 ) and superior rate performance.

Tetrabutylammonium‐Intercalated 1T‐MoS2 Nanosheets with Expanded Interlayer Spacing Vertically Coupled on 2D Delaminated MXene for High‐Performance Lithium‐Ion Capacitors

Abstract2D 1T phase MoS2 (1T‐MoS2) nanosheet with metallic conductivity and expanded interlayer spacing is considered as a highly potential lithium storage electrode material but remains thermodynamic instability in aqueous media, seriously hindering the electrochemical performance. Herein, a versatile strategy is proposed for the preparation of thermodynamically stable 1T‐MoS2/MXene heterostructures with the aid of delaminated Ti3C2Tx MXene (d‐Ti3C2Tx) dispersion containing tetrabutylammonium hydroxide. The 2D d‐Ti3C2Tx provides more uniform nucleation sites for MoS2, and the TBA+ ions can intercalate into MoS2 to induce the phase conversion from semiconducting 2H to 1T. Moreover, the electrochemical advantages of 1T‐MoS2 and d‐Ti3C2Tx can be united by the construction of a well‐organized heterostructure. Outstanding rate performance is realized because of extra‐large interlayer space of 1T MoS2 with TBA+ intercalation and decreased energy barrier for fast Li+ diffusion. Subsequently, a lithium‐ion capacitor (LIC) is assembled based on 1T‐MoS2/d‐Ti3C2Tx as anode and hierarchically porous graphene nanocomposite with micro/mesoporous structure as a cathode. The LIC exhibits a large energy density up to 188 Wh kg−1, an ultra‐high power density of 13 kW kg−1, together with remarkable capacity retention of 83% after 5000 cycles. This study demonstrates the great promise of 1T‐MoS2/d‐Ti3C2Tx heterostructures as anode for high‐performance LICs.

Li2CO3 induced stable SEI formation: An efficient strategy to boost reversibility and cyclability of Li storage in SnO2 anodes

The unstable interfaces between a SnO2 anode and an electrolyte in a Li-ion battery dramatically impair the reversibility and cycling stability of lithiation and delithiation, resulting in low roundtrip Coulombic efficiency (CE) and fast capacity decay of SnO2-based anode materials. Herein, a simple strategy of modifying the solid electrolyte interphase (SEI) is developed to enhance the interfacial stability and lithium storage reversibility of SnO2 by compositing it with graphite (G) and an inorganic component of the SEI, such as Li2CO3 or LiF, which results in the SnO2-Li2CO3/G and SnO2-LiF/G composite anodes with high CEs, large capacities and long cycle lives. Specifically, the SnO2-Li2CO3/G composite anode exhibits an average initial CE of 79.6%, a stable reversible capacity of 927.5 mA h g−1 at a current rate of 0.2 A g−1, and a charge capacity over 1200 mA h g−1 with a CE >99% after 900 cycles at a higher current rate of 1 A g−1. It is revealed that Li2CO3 induces the formation of a dense and stable SEI on SnO2 grains and inhibits the coarsening of nanosized Sn particles generated from the dealloying reaction in the SnO2-Li2CO3/G electrode. Moreover, the CE and cycling stability of other alloying type (Si) and conversion reaction (MnO2 and Fe3O4) anodes can also be greatly promoted by simply milling with Li2CO3. Thus, a universal and simple strategy is developed to achieve highly reversible and stable electrodes for large capacity lithium storage.

Rational design of bamboo mat-like 3D Ni foam@NiO@PPy nanoarray electrode for binder-free, high-loading and high-areal capacity lithium storage

Achieving high capacity and good cyclability of transition metal oxides anodes remains a challenge for lithium-ion batteries (LIBs) because of their poor conductivity and severe volume change. In this work, a bamboo mat-like nanoarray electrode consisting of NiO nanoarray interlayer and polypyrrole (PPy) coating layer growing directly on three-dimensional nickel foam (3D NF) conductive substrate (denoted as 3D NF@NiO@PPy) is reported to overcome the challenge. The 3D NF current collector can provide more active growth sites and thus achieve high loading (about 5.5 mg cm–2). The bamboo mat-like NiO nanoarray reduces the Li+ ions diffusion path and enhances the contact surface areas with the electrolyte, which can improve the electrochemical properties. The in-situ growth PPy coating can not only effectively suppress the volume expansion of NiO during the charge and discharge process, but also effectively improve the electrical conductivity of the electrode within a certain thickness range. Benefiting from this unique structure, the as-obtained 3D NF@NiO@PPy binder-free nanoarray electrode exhibits stable cycle performance and high reversible areal capacity of 4.90 mA h cm-2 at 0.5 mA cm-2. Remarkably, a large reversible capacity of 1.10 mA h cm-2 is also achieved even after 200 cycles at a relatively high current density of 2.5 mA cm-2. This work proposes a feasible strategy to enhance the capacity and stability of NiO anode and provides a new way for the practical application of self-supporting electrodes.

Molten Salt Derived Nb2CTx MXene Anode for Li‐ion Batteries

Abstract2D MXenes, are receiving increasing attention thanks to their outstanding performance for electrochemical energy‐storage applications. So far, Ti3C2 is the most studied MXene, while less effort is dedicated to investigating many other MXenes. In this paper, we report the preparation of Nb2CTx MXene by Lewis acidic etching in molten salts. The achieved Nb2CTx MXene is able to deliver a maximum lithium storage capacity up to 330 mAh g−1 at 0.05 A g−1, outperforming the maximum capacity (205 mAh g−1) achieved by molten salt derived Ti3C2Tx MXene. The high‐rate performance is also obtained with a capacity of 80 mAh g−1 at 10 A g−1 (100 C). This work highlights the promising potential of Nb‐based MXenes to be explored as high‐rate lithium storage electrodes.

Light-Assisted Rechargeable Lithium Batteries: Organic Molecules for Simultaneous Energy Harvesting and Storage.

Lithium batteries that could be charged on exposure to sunlight will bring exciting new energy storage technologies. Here, we report a photorechargeable lithium battery employing nature-derived organic molecules as a photoactive and lithium storage electrode material. By absorbing sunlight of a desired frequency, lithiated tetrakislawsone electrodes generate electron-hole pairs. The holes oxidize the lithiated tetrakislawsone to tetrakislawsone while the generated electrons flow from the tetrakislawsone cathode to the Li metal anode. During electrochemical operation, the observed rise in charging current, specific capacity, and Coulombic efficiency under light irradiation in contrast to the absence of light indicates that the quinone-based organic electrode is acting as both photoactive and lithium storage material. Careful selection of electrode materials with optimal bandgap to absorb the intended frequency of sunlight and functional groups to accept Li-ions reversibly is a key to the progress of solar rechargeable batteries.

In-situ growth of TiO2 film on carbonized eggshell membrane as 3D electrode for high-performance lithium storage

3D electrodes have shown extraordinary promise for electrochemical energy storage devices in wearable electronics. However, it is still a significant challenge to rationally design 3D electrode that has the characteristics of lightweight, flexibility, low cost, high performance and miniaturization. In this work, we present a novel design of 3D electrode by directly growing the nanocrystalline TiO2 film on carbonized eggshell membrane. The unique architecture can supply not only a continuous electron transport pathway through an interconnected carbon fibrous network but also an efficient electrolyte flux via an interpenetrating porous network. Besides, nanocrystalline TiO2 film on carbonized eggshell membrane offers a short ion diffusion path in the solid-phase, leading to a rapid kinetic of electrochemical reaction. When tested as an anode for Li-ion battery, TiO2 film in 3D electrode demonstrated excellent electrochemical performance with a large reversible capacity, excellent rate capacity and long life cycling property.

Three-dimensional porous SnO2/carbon cloth electrodes for high-performance lithium- and sodium-ion batteries

The tin oxide nanoparticles (SnO2-NPs) were successfully synthesized on the conductive carbon cloth (CC) using a simple one-step solvothermal method to form three-dimensional (3D) porous SnO2/CC composite. The SnO2-NPs were uniformly deposited on CC and fine pores existed between the SnO2-NPs. The synthesized 3D porous SnO2/CC composite was investigated as an anode material for lithium-ion batteries (LIBs) and sodium-ion batteries (SIBs). When tested as an anode for LIBs, the as-prepared 3D porous SnO2@CC composite electrode delivered a discharge capacity of 1038 mA h g−1 over 200 cycles at a current density of 0.5 A g−1. For SIBs, a discharge capacity of 498 mA h g−1 was delivered at 0.2 A g−1 over 100 cycles. Even at 0.5 A g−1, the electrode exhibited a discharge capacity of 205 mA h g−1 over 100 cycles. The excellent electrochemical properties of 3D porous SnO2/CC composite electrode for both lithium and sodium storage can be attributed to the good porous structure between the SnO2-NPs on the surface of CC and improved electrical conductivity due to CC, which not only releases the strain during the Li+/Na+ insertion/extraction process but also can improve the ionic and electronic transportation.

Amorphous MoS3 decoration on 2D functionalized MXene as a bifunctional electrode for stable and robust lithium storage

The development of electrode materials with the synergistic effects of good chemical stability and high electrical conductivity has improved the sluggish ion kinetics and severe capacity degradation of rechargeable lithium batteries. Herein, a multifunctional heterostructure material (MoS3-Ti3C2Tx) comprising a functionalized MXene (Ti3C2Tx) and amorphous MoS3 is prepared by a scalable electrostatic self-assembly method. Remarkably, as lithium-ion battery anodes, the resultant MoS3-Ti3C2Tx not only exhibits increased electrochemical activity, accelerated lithium-ion diffusion and fast charge transfer kinetics but also shows high specific capacity, excellent rate performance and long-term cycling stability. By virtue of these merits, MoS3-Ti3C2Tx offers an excellent reversible capacity of 1043 mAh g−1 at 200 mA g−1 and exhibited a capacity of 568 mAh g−1 at a current density of 2 A g−1 after 1000 cycles. When acting as the cathode for lithium-sulfur batteries, the amorphous MoS3 anchored on MXene demonstrates high capture and catalytic activity towards polysulfide conversion. Accordingly, the optimized electrode exhibits a capacity of 836 mAh g−1 at 0.2C after 100 cycles and a satisfactory rate performance of 463 mAh g−1 at 2C after 400 cycles. Moreover, the associated conversion mechanism is studied by ex situ XPS. These results demonstrate that heterostructure composites constructed by an amorphous sulfide and surface functionalized MXene are feasible electrode materials for both lithium-sulfur batteries and lithium-ion batteries.

Long-term cycling of core-shell Fe3O4-Polypyrrole composite electrodes via diffusive and capacitive lithiation

Abstract Core-shell Fe3O4-polypyrrole (Fe3O4-PPy) composites are synthesized by etching and polymerization to address the capacity degradation and low Coulombic efficiency (CE) of the Fe3O4 electrodes for lithium storage. When the weight content of Fe3O4 is 60%, a conformal carbon-coated Fe3O4 composite is formed, which can retain a charge capacity of 451 mAh g−1 after 800 cycles at 2 C with a high initial CE of 74.8%. The diffusive and capacitive contribution to the capacity are evulated, demonstating the advantages of the synergistic lithiation of the Fe3O4-PPy electrodes.

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.