High-performance Lithium Storage Research Articles

The Facile and Controllable Synthesis of Ultrafine Sn Nanocrystals Loaded on Carbon Black for High-Performance Lithium Storage.

Sn and C nanocomposites are ideal anode materials for high-energy and high-power density lithium ion batteries. However, their facile and controllable synthesis for practical applications is still a critical challenge. In this work, a facile one-step method is developed to controllably synthesize ultrafine Sn nanocrystals (< 5 nm) loaded on carbon black (Sn@C) through Na reducing SnCl4 by mechanical milling. Different from traditional up-down mechanical milling method, this method utilizes mechanical milling to trigger bottom-up reduction reaction of SnCl4. The in-situ formed Sn nanocrystals directly grow on carbon black, which results in the homogeneous composite and the size control of Sn nanocrystals. The obtained Sn@C electrode is revealed to possesses large lithium diffusion coefficient, low lithiation energy barrier and stable electrochemical property during cycle, thus showing excellent lithium storage performance with a high reversible capacity (942 mAh g-1 at a current density of 100 mA g-1), distinguished rate ability (480 mAh g-1 at 8000 mA g-1) and superb cycling performance (730 mAh g-1 at 1000 mA g-1 even after 1000 cycles).

Melamine Polymerization Promotes Compact Phosphorus/Carbon Composite for High-Performance and Safe Lithium Storage.

Phosphorus is regarded as a promising material for high-performance lithium-ion batteries (LIBs) due to its high theoretical capacity, appropriate lithiation potential, and low lithium-ion diffusion barrier. Phosphorus/carbon composites (PC) are engineered to serve as high-capacity high-rate anodes; the interaction between phosphorus and carbon, long-term capacity retention, and safety problems are important issues that must be well addressed simultaneously. Herein, an in situ polymerization approach to fabricate a poly-melamine-hybridized (pMA) phosphorus/carbon composite (pMA-PC) is employed. The pMA hybridization enhances the density and electrical conductivity of the PC, improves the structural integrity, and facilitates stable electron transfer within the pMA-PC composite. Moreover, the pMA-PC composite exhibits efficient adsorption of lithium polysulfides, enabling stable transport of Li+ ions. Therefore, the pMA-PC anode demonstrates a high specific charging capacity of 1,381mAhg-1 at 10Ag-1, and a great capacity retention of 86.7% at 1Ag-1 over 500 cycles. The synergistic effect of phosphorus and nitrogen further confers excellent flame retardant properties to the pMA-PC anode, including self-extinguishing in 2.5s, and a much lower combustion temperature than PC. The enhanced capacity and safety performance of pMA-PC show potential in future high-capacity and high-rate LIBs.

Identification of polypyrrole-encapsulated BiSCl as a viable conversion/alloying anode material for high-performance lithium storage

Anode materials combining conversion and alloying mechanisms are increasingly valued in advanced rechargeable batteries for their exceptional theoretical capacities and advantageous working voltages. This study showcases BiSCl as a promising conversion/alloying anode material, demonstrating a high specific capacity and enhanced durability through polypyrrole encapsulation. Employing in situ X-ray diffraction, X-ray photoelectron spectroscopy, ex situ transmission electron microscopy, and field emission scanning electron microscopy, we offer a detailed analysis of the lithiation mechanism in BiSCl. The anode exhibits a low average working potential of approximately 0.6 V, supporting a theoretical specific capacity of 784 mAh/g and a volumetric capacity of 4664 mAh/cm3. The innovative BiSCl-PPy core-shell composite effectively addresses the challenges of volumetric expansion and polysulfide dissolution. This composite delivers a remarkable reversible capacity of 753 mAh/g at a current rate of 100 mA/g, maintaining 96% of its specific capacity over 400 cycles, and sustains 419 mAh/g at 500 mA/g after 800 cycles, demonstrating more superior performance than that of BiSCl. These findings establish BiSCl as a highly promising conversion/alloying anode material for lithium storage, significantly enhanced in durability by the BiSCl-PPy core-shell composite.

Carbon-coated TiNb2O7 microspheres with partial nitridation for high-performance lithium storage

TiNb2O7 has been applied to lithium-ion batteries owing to its large capacity and inherent safety, but suffers from its poor rate capability. Here, TiNb2O7 is modified through a combination of crystal-structure modification and conductive-phase coating, and C–NH3–TiNb2O7 with Ti2Nb[Formula: see text]O[Formula: see text]-type TiNb2O7 and Ti[Formula: see text][Formula: see text]Nb[Formula: see text]N/carbon double coatings is successfully synthesized. The unique Ti2Nb[Formula: see text]O[Formula: see text]-type structure of TiNb2O7 owns a large interlayer spacing, leading to fast Li[Formula: see text] diffusivity and remarkable intercalation-pseudocapacitive behavior. The conductive Ti[Formula: see text][Formula: see text]Nb[Formula: see text]N/carbon coatings result in good electrical conduction among the TiNb2O7 microspheres. Consequently, C–NH3–TiNb2O7exhibits excellent rate capability of TiNb2O7 (large capacity percentage of 73.9% at 5C versus 0.5C). Besides the fast electrochemical kinetics, C–NH3–TiNb2O7 further exhibits large reversible capacities (237 mAh g[Formula: see text]at 0.1C and 146 mAh g[Formula: see text]at 5C) and outstanding cyclability (93.1% capacity retention after 500 cycles at 5C). These desirable electrochemical properties fully demonstrate that the C–NH3–TiNb2O7 anode material can be suitable for high-performance Li[Formula: see text]-storage.

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.

Ni-Co MOF-derived rambutan-like NiCo2O4/NC composite anode materials for high-performance lithium storage

Taking advantage of the large surface area and high porosity characteristic of metal-organic framework (MOF) materials, the synthesis of carbon-coated bimetallic transition metal oxides stands out as an effective strategy to reduce volume expansion, enhance cycling stability, and improve electronic conductivity at the active sites in lithium-ion batteries (LIBs). In this research, a novel rambutan-like Ni-Co MOF was successfully synthesized via a hydrothermal method followed by calcination to obtain nitrogen-doped carbon-stabilized hierarchical rambutan-like NiCo2O4 composites (NiCo2O4/NC). The resulting composites inherited the original rambutan-like structure of the Ni-Co MOF, which was characterized by uniform size, highly ordered porosity and large surface area, and showed excellent electrochemical Li+ storage performance. In particular, the NiCo2O4/NC-600 composite exhibited superior cyclic stability and rate capability, maintaining a remarkable reversible charge/discharge specific capacity of 1281.7/1292.7 mAh g−1 after 400 cycles at 0.5 A g−1. In addition, when paired with LiFePO4 in a full cell, it maintained a reversible discharge specific capacity of 143.9 mAh g−1 after 200 cycles at 0.1 A g−1, indicating commendable cyclic stability. Ex-situ analyses confirmed the pseudo-capacitive behavior of the NiCo2O4/NC composites. Furthermore, the nitrogen-doped carbon layer embedded in the NiCo2O4/NC composites effectively mitigated the volume expansion during repeated Li stripping/plating processes, thereby improving the structural integrity, conductivity, and specific capacitance. This study presents a practical approach for fabricating nitrogen-doped carbon-stabilized bimetallic oxide anodes in high-power LIBs through architectural engineering and compositional tailoring.

Hierarchical core-shell structured CoZn-MOFs derived materials anode with raspberry-like shape for high-performance lithium storage

Significant progress had been made in various fields with transition metal oxide electrode materials, particularly in battery materials where structural control played a crucial role in enhancing their electrochemical properties. Therefore, this study aimed to investigate the potential of a raspberry-like hierarchical core-shell structure derived from Co–Zn MOF as anode materials by varying concentration of reaction solution in hydrothermal method. The hierarchical raspberry-like hollow shell structure was beneficial to expose more active sites and reduced the diffusion distance of Li+ to the internal electroactive sites, improving the overall electrical conductivity of the electrode by full contact with carbon. Carbon nanotubes were incorporated into more suitable core-shell structure. They were uniformly coated the hollow sphere and filled inside of that to form a carbon skeleton. Specifically, the carbon nanotubes inside of the hollow sphere supported the shell not to collapse. This mitigated volume expansion during the cycling process, maintains structure stability, and allowed for rearrangement to occur during cycling to achieve a high specific capacity. Furthermore, the carbon nanotubes inside and outside of the hollow sphere created a high-density interface that enhanced interfacial polarisation and accelerated the rate of Li+ passage during cycling. These effects had resulted in an improvement in the material's performance. It is noteworthy that the specific capacity attains 1050 mAh g-1 when exposed to a current density of 0.2 A g-1. Notably, even after conducting 500 cycles at a current density of 0.5 A g-1, the specific capacity remains stable at 652 mAh g-1.

Tin-carbon composite submicron spheres constructed by molten salt synthesis and their high lithium storage performance

To effectively alleviate the severe agglomeration and huge volume expansion of tin oxides during charge and discharge processes, tin-carbon composite (SnOx@C-M) submicron spheres are constructed in this work using a molten salt-assisted method to improve their lithium storage performance. SnOx@C-M submicron spheres mainly comprises SnOx nuclei encapsulated by an amorphous carbon layer. The aggregation of SnOx nanoparticles can be enhanced by the surface carbon layer, allowing the significant volume expansion during cycling to be buffered. As expected, decent cycling stability and multiplicative properties were realized in the SnOx@C-M electrode material. Hence, this work is expected to provide a workable method to improve the performance of tin-carbon composites.

Dual modification strategies of Fe doping and carbon coating for MnO anode: A facile achieving route and high lithium storage performance

MnO attracts increasing attention as a lithium-ion battery anode material due to large theoretical capacity and relatively low cost, but its highly instable structure and low conductivity severely plague cycling stability. In addition to improved performance, easy preparation is also important for the development of MnO anode, and hence both of these aspects need attention. Toward this end, herein, a high-performance MnO-based anode material, composed of carbon coated porous nanoclusters assembled from smaller secondary Fe-doped MnO nanoparticles (denoted as Fe-MnO@C), has been prepared through a facile route. The findings demonstrate that the combination of Fe doping and carbon coating enables Fe-MnO@C to have higher structural stability and faster electrochemical kinetics than MnO and MnO@C counterparts. As a result, Fe-MnO@C anode shows outstanding lithium storage performances, maintaining 1038.4 and 512.3 mAh g−1 at 200 and 1000 mA g−1 after 320 and 400 cycles, respectively. Finally, this work not only offers a feasible method for improving MnO anode performance, but also gives a constructive reference for designing facile methods to prepare other advanced metal oxide-based anode materials.

Micelle-directed self-assembly of single-crystal-like mesoporous stoichiometric oxides for high-performance lithium storage.

Due to their uncontrollable assembly and crystallization process, the synthesis of mesoporous metal oxide single crystals remains a formidable challenge. Herein, we report the synthesis of single-crystal-like mesoporous Li2TiSiO5 by using soft micelles as templates. The key lies in the atomic-scale self-assembly and step-crystallization processes, which ensure the formation of single-crystal-like mesoporous Li2TiSiO5 microparticles via an oriented attachment growth mechanism under the confinement of an in-situ formed carbon matrix. The mesoporous Li2TiSiO5 anode achieves a superior rate capability (148mAhg-1 at 5.0Ag-1) and outstanding long-term cycling stability (138mAhg-1 after 3000 cycles at 2.0Ag-1) for lithium storage as a result of the ultrafast Li+ diffusion caused by penetrating mesochannels and nanosized crystal frameworks (5-10nm). In comparison, bulk Li2TiSiO5 exhibits poor rate capability and cycle performance due to micron-scale diffusion lengths. This method is very simple and reproducible, heralding a new way of designing and synthesizing mesoporous single crystals with controllable frameworks and chemical functionalities.

Facile preparation of MoO3@Mo2CT x nanocomposite with high lithium storage performance by in situ oxidation

In this work, a new MoO3@Mo2CT x nanocomposite was prepared from two–dimensional (2D) Mo2CT x MXene by in situ oxidization in air, which exhibited wonderful lithium-storage performance as anodes of lithium–ion batteries (LIBs). The precursor Mo2CT x was synthesized from Mo2Ga2C by selective etching of NH4F at 180 °C for 24 h. Thereafter, the Mo2CT x was oxidized in air at 450 °C for 30 min to obtain MoO3@Mo2CT x nanocomposite. In the composite, in situ generated MoO3 nanocrystals pillar the layer structure of Mo2CT x MXene, which increases the interlayer space of Mo2CT x for Li storage and enhances the structure stability of the composite. Mo2CT x 2D sheets provide a conductive substrate for MoO3 nanocrystals to enhance the Li+ accessibility. As anodes of LIBs, the final discharge specific capacity of the MoO3@Mo2CT x composite was 511.1 mAh g–1 at a current density of 500 mA g–1 after 100 cycles, which is about 36.7 times that of pure Mo2CT x MXene (13.9 mAh g–1) and 3.2 times that of pure MoO3 (159.9 mAh g–1). In the composites, both Mo2CT x and MoO3 provide high lithium storage capacity and can enhance the performance of each other. Moreover, this composite can be made by a facile method of in situ oxidation. Therefore, the MoO3@Mo2CT x MXene nanocomposite is a promising anode of LIB with high performance.

Mo doping V0.76Mn0.032Ni0.029O2 vanadium based ternary metal oxides as cathode active materials for lithium-ion hybrid supercapacitor with high lithium storage performance

Lithium-ion hybrid supercapacitors as high-performance energy storage devices are proposed to bridge the electrochemical performances between lithium-ion batteries and supercapacitors. In this paper a novel Mo doping V0.76Mn0.032Ni0.029O2 vanadium based ternary metal oxide is constructed as cathode active material for lithium-ion hybrid supercapacitor. Structural analysis demonstrates Mo doping as interlayer support can ameliorate the V0.76Mn0.032Ni0.029O2 crystal structure and raise the lattice size thus providing more adequate mass transfer channels for lithium-ion storage. In addition, 5 % Mo doping V0.76Mn0.032Ni0.029O2 represents relatively regular crystal particle arrangement with some integrated crystalline form and closely packing together. These structural features enable them to exhibit higher lithium storage performance and when as cathode active material for lithium-ion hybrid supercapacitor, it exhibits the lowest electrochemical and concentration polarization and the highest discharge specific capacities of 150.7, 140.2, 125.4 and 102.5 mAh.g−1 at different current densities along with a high capacity retention rate of 77.3 % at 1000 mA g−1 current density after 2000 cycles.

Effective combination of Fe2O3 with hierarchical porous carbon for high-performance lithium storage

Effective combination of Fe2O3 with hierarchical porous carbon for high-performance lithium storage

High-performance lithium storage in Li2SnO3-graphite composite enabled by Ag3Sn nanoparticles and oxygen vacancies

With high capacity (653 mAh g−1) and low voltage (0.6 V), Li2SnO3 is considered as a prospective anode material for Li-ion batteries (LIBs). Nevertheless, its practical uses are restricted by inferior electrochemical kinetics and fast capacity decay. Herein, a novel ternary composite of Ag3Sn alloy-lithium stannate-graphite (denoted as Ag3Sn-Li2SnO3-x-G) is designed and fabricated by ball milling and vacuum annealing. In this ternary composite, oxygen vacancy-containing Li2SnO3 and Ag3Sn alloy nanoparticles are homogeneously dispersed in the exfoliated graphite nanosheets. The introduction of Ag3Sn nanoparticles and oxygen vacancies into Li2SnO3-graphite can significantly enhance charge transport kinetics and structure stability of composite during the lithiation and delithiation processes. Benefiting from these merits, the Ag3Sn-Li2SnO3-x-G composite presents excellent cycling stability (782.4 mAh g−1 at 0.2 A g−1 after 200 cycles) and impressive rate capability (251.5 mAh g−1 at 2 A g−1). Broadly, this design strategy can provide an effective and reliable route for constructing advanced metal oxide-based anode materials for high-energy LIBs.

Interpenetrating gel-enabled uniform integration of metal and carbon dual matrices with nanoporous silicon for high-performance lithium storage

An interpenetrating gel-enabled methodology has been developed for uniformly integrating metal and carbon with nanoporous silicon, enabling enhanced lithium-storage performance of Si–M–C ternary anodes.

CdS@C nanowires with rich sulfur vacancies for high-performance lithium storage anodes

CdS@C nanowires with rich sulfur vacancies for high-performance lithium storage anodes

Dual immobilization of porous Si by graphene supported anatase TiO2/carbon for high-performance and safe lithium storage

Smart surface coatings have been proven to be an effective strategy to significantly enhance the electronic conductivity and cycling stability of silicon-based anode materials. However, the single/conventional coatings face critical challenges, including low initial Coulomb efficiency (ICE), poor cyclability, and kinetics failure, etc. Hence, we proposed a dual immobilization strategy to synthesize graphene supported anatase TiO2/carbon-coated porous silicon composite (denoted as PSi@TiO2@C/Graphene) using industrial-grade ferrosilicon as lithium storage raw materials through the simple etching, combined with sol–gel and hydrothermal coating processes. In this work, the dual immobilization from the “confinement effect” of the inner TiO2 shell and the “synergistic effect” of the outer carbon shell, improves the kinetics of the electrochemical reaction and ensures the integrity of the electrode material structure during lithiation. Furthermore, the introduction of the graphene substrate offers ample space for dispersing and anchoring the Si-based granules, which in turn provides a stable 3D conductive network between the particles. As a result, the PSi@TiO2@C/Graphene electrode delivers high reversible capacity of 1605.4 mAh g−1 with 93.65% retention at 0.5 A g−1 after 100 cycles (vs. 4th discharge), high initial Coulomb efficiency (82.30%), and superior cyclability of 1159.9 mAh g−1 after 250 cycles. The above results suggest that the particle structure has great potential for applications in Si-based anode and may provide some inspiration for the design of other energy storage materials.

Sn3O4 nanosheets with N-doped carbon coating for high performance lithium storage

Tin-based oxides are promising anode materials for lithium ion batteries (LIBs) in virtue of their many advantages including high capacity, abundant reserves and environmental friendliness. Yet, previous studies mainly focus on the SnO2-based anodes for lithium storage. Considering that the mixed valence and layered crystal structure of Sn3O4 may lead to better lithium storage properties, Sn3O4-based anode material is designed and synthesized through a facile hydrothermal method in this work. The as-prepared Sn3O4 nanosheets are coated with N-doped carbon layers (∼15 nm) on both sides through dopamine polymerization and subsequent polydopamine carbonization to solve the issues of poor intrinsic electronic conductivity and drastic volume change during LiSn alloying/dealloying, which have hindered their application in LIBs. With the structural and composition advantages brought by the thick N-doped carbon layers, the Sn3O4@NC nanosheets delivered a remarkable reversible capacity (1222 mAh g−1 after 50 cycles at 200 mA g−1) and excellent rate performance when applied in LIB as anode material, owing to the improved electrical conductivity and strengthened structure stabilities. Importantly, we demonstrate a convenient strategy to realize carbon coating in the fabrication of Sn3O4-based anode materials, which could inspire the development of other Sn3O4-based anode materials with excellent lithium storage properties.

One-step synthesis of dual-ligand 2D conductive metal-organic framework for high-performance lithium storage

One-step synthesis of dual-ligand 2D conductive metal-organic framework for high-performance lithium storage

Cationic surfactant assisted electrostatic self-assembly of nitrogen-rich carbon enwrapped silicon anode: Unlocking high lithium storage performance

Nitrogen-rich carbon (N-rich-C) coating is attractive to enhance capacity, reduce resistance, and alleviate volume expansion of silicon anode in Li-ion batteries. However, the non-uniform coating of N-rich-C on silicon might restrict its optimum performance. In this study, poly(diallyldimethylammonium chloride) (PDDA) is employed as a cationic surfactant to tailor the surface potential of bare ball-milled Si particles, enabling the electrostatic self-assembly between Si particles and graphitic carbon nitride as the N-rich-C precursor. Continuous N-rich-C enwrapped ball-milled silicon (Si@N-rich-C) has been obtained after pyrolysis with a high N to C ratio of 0.65 and abundant pyridinic-N and pyrrolic-N, facilitating fast kinetic transport and accommodating more Li+ ion storage. Combined with the high capacity of Si, Li-ion cell with Si@N-rich-C electrode exhibits a high capacity of 1732 mAh g−1 after 200 cycles of charge-discharge at 400 mA g−1. At high-rate testing, Si@N-rich-C also maintains a high capacity of 1673 mAh g−1 at 1000 mA g−1. This study provides an effective approach for synthesizing high-capacity silicon anode for Li-ion batteries.