Excellent Lithium Storage Performance Research Articles

Fabricating a high-performance anode by coating a carbon layer on a yolk-shell bimetallic selenide microsphere for enhanced lithium storage.

The rational synthesis of an electrode material with a highly active and stable architecture is very critical to achieving high-performance electrochemical energy storage. Herein, N-doped carbon restricting yolk-shell CoSe2/Ni3Se4 (CoSe2/Ni3Se4@NC) flower-like microspheres were successfully synthesized from solid CoNi-glycerate microspheres using a coating technology as an anode material for lithium-ion batteries (LIBs). The unique yolk-shell CoSe2/Ni3Se4@NC microspheres with hierarchical pores can increase the contact area with the electrolyte and provide enough transfer channels for the diffusion of Li+. The carbon layer on the surface of CoSe2/Ni3Se4@NC can not only improve the conductivity of the electrode but also provide the protective effect of active nanosheets during the process of synthesis, avoiding the overall structure collapse during the charge/discharge process of LIBs. Benefiting from the high conductivity, hollow structure, and elastic NC shell bestowed by the unique architecture, the yolk-shell CoSe2/Ni3Se4@NC anode shows excellent lithium storage performances, such as an excellent reversible specific capacity of 319 mA h g-1 at a current density of 1000 mA g-1 after 500 cycles and excellent cycling stability. This synthesis strategy provides a new way to optimize the lithium storage performance of transition metal compound electrode materials, which is helpful to the design of the next generation of high-performance LIBs.

An olivine LiFe0.5Mn0.5PO4/rGO composite cathode material prepared from manganese ore tailings with excellent lithium storage performance

An olivine LiFe0.5Mn0.5PO4/rGO composite cathode material prepared from manganese ore tailings with excellent lithium storage performance

Fabrication of FeP2/C/CNTs@3D interconnected graphene aerogel composite for lithium-ion battery anodes and the electrochemical performance evaluation using machine learning

Featuring low cost and high theoretical capacity, phosphorus-rich iron diphosphides (FeP2) have emerged as excellent anode candidates for lithium-ion batteries. However, the typical chemical synthses involving high temperatures and toxic gases have restricted the mass production of FeP2. We now report a FeP2/C/CNTs@3D interconnected graphene aerogel composite synthesized by ball milling and low temperature heat treatment. Because of the unique microstructure and synergistic effect between well-dispersed FeP2 particles and graphene aerogel, the as-prepared FeP2/C/CNTs@GA-2.5% displays excellent lithium storage performance in terms of reversible capacity (886 mA h g−1 at 0.1 A g−1), cycling stability (476 mA h g−1 at 2 A g−1 even after 1000 cycles), and rate capability (685 mA h g−1 at 5 A g−1). Machine learning methods (decision tree and random forest algorithms) prove effective in evaluating and predicting electrochemical performance of the electrode materials.

Unveiling the effects of different component ratios on the structure and electrochemical properties of MoS2/TiO2 composites

In this study, a composite material comprising of MoS2 and TiO2 was designed, and the TiO2 content in the composite was systematically varied to enhance the rate capability and cycling performance of MoS2. The optimized composite structure (MT-3 with a mass ratio of MoS2 to TiO2 of 8:1) ensures stable connections between the flower-like MoS2 and TiO2 nanosheets through robust covalent Ti–O–S bonds, effectively enhancing the electrochemical reaction kinetics and thus improving lithium storage performance. Additionally, the incorporation of an appropriate amount of TiO2 alleviates the stacking of MoS2, increasing the number of electrochemically active sites. The specific capacities of MT-3 at current densities of 0.1, 0.5, 1, 2, and 5 A g−1 are 1172.9, 1039.3, 921.6, 864.9, and 696.5 mA h g−1, respectively. Furthermore, even after 100 cycles at 2 A g−1, it still maintains a high specific capacity of 694 mA h g−1, indicating excellent lithium storage performance. This synergistic strategy between MoS2 and TiO2 holds promise for the rational design of high-performance anode materials for LIBs.

Molten salts synthesis of NbB nanoparticles for lithium-ion capacitor applications

Lithium-ion capacitors (LICs), despite having great energy density and power density, possess many practical challenges, including matching optimization of kinetic imbalance. To address the issues, here, niobium monoboride (NbB) nanoparticles are presented as an anode material for LICs. The abundant pore size distribution and intercalation-type Li+ storage mechanism of NbB nanoparticles allow for fast redox kinetics in charge and discharge process. Therefore, the half-cells with NbB achieve excellent electrochemical performance, including a great capacity (197 mAh g-1 at 0.1 A g−1 for 1000 cycles) and superior cycle life (118 mAh g-1 at 1 A g−1 for 5000 cycles). Also, NbB//AC LIC-1 device fabricated with the NbB as anode and commercial activated carbon (AC) as cathode reveals a great specific capacitance of 28.1 F g−1 at 0.05 A/g, and remains over 70 % initial capacitance after 12,000 cycles. In this work, nanoscale NbB presents excellent lithium storage performance and matches well with carbon cathodes, indicating that transition metal borides (TMBs) have huge potential in the energy storage field.

Spray pyrolysis-derived W-doped MoSe2/rGO paper-like microspheres: optimization of microstructure and mesostructure for enhanced lithium storage

Two-dimensional MoSe2 is a promising candidate for lithium-ion battery anodes. However, its conductivity and lithium storage volumetric effect still need to be optimized. In this work, W-doped MoSe2/rGO paper-like microspheres are successfully prepared through ultrasonic spray pyrolysis, achieving optimization at both the microstructure and mesostructure to enhance the lithium storage performance of the material. Firstly, by utilizing the similar two-dimensional structure between MoSe2 and rGO, self-assembly is achieved through spray pyrolysis, resulting in a well-defined van der Waals heterostructure at the interface on the microscale, enhancing the electron and ion transfer capability of the composite. Secondly, the mesoscale paper-like microsphere morphology provides additional volume expansion buffering space. Moreover, W-doping not only increases the interlayer spacing of MoSe2 (0.73 nm), thereby reducing the diffusion resistance of Li+, but also allow for the modulation of the energy band structure of the material. Density functional theory (DFT) calculations confirm that W-doped MoSe2/rGO exhibits the narrowest bandgap (0.892 eV). Therefore, the composite demonstrates excellent lithium storage performance, maintaining a specific capacity of 732.9 mAh·g−1 after 300 cycles at a current density of 1 A·g−1.Graphical abstract

An in-situ cross-linked network PMMA-based gel polymer electrolyte with excellent lithium storage performance

Gel polymer electrolytes (GPEs) effectively combine the advantages of high ionic conductivity and reduce the risk of leakage associated with liquid. In this study, a chemically cross-linked gel polymer electrolyte was prepared by in-situ polymerization using polymethyl methacrylate (PMMA) as a matrix and neopentyl glycol diacrylate (NPGDA) as cross-linking agent. The cross-linked structure of the GPE was preliminarily investigated, as well as the influence of the degree of cross-linking on its physical properties. The GPE exhibited a superior conductivity of 1.391 mS cm−1 at 25 °C. Herein, the Li|GPE|LiNi0.8Co0.1Mn0.1O2 cell has an excellent capacity retention rate of 80.7% after 150 cycles at 0.5 C in addition to a high discharge specific capacity of 203 mAh g−1. The structure of the cathode material is shielded from the production of byproducts during the charging and discharging of lithium-ion batteries by the cross-linked PMMA GPE.

Porous Co3O4/NiO@C Chains Assembled from Nanosheets with Excellent Lithium Storage Performance.

Carbon layers-coated porous Co3O4/NiO (denoted as PCNO@C) chains are synthesized by the facile solvothermal method and subsequently annealing treatment under an Ar atmosphere, which are assembled from numerous Co3O4/NiO nanosheets. Benefiting from the unique porous chain structure, the volume change of the electrode is greatly relieved during the long-term cycling processes, and then an excellent cycling stability is obtained (the reversible specific capacity of the 1000th cycle can reach 637.3 mA h g-1 at 5000 mA g-1). Besides, a continuous conductive network is constructed by the coated carbon layers and long chains, the movement rate of electrons is effectively accelerated, and the high rate capability is obtained (the high reversible specific capacity of 480.6 mA h g-1 is retained at 10,000 mA g-1). This work contributes a new idea to construct porous chain structure anode materials.

Graphene oxide wrapped porous NiO/CNT microspheres with excellent lithium storage performance

Three-dimensional porous NiO/CNT microspheres are constructed by the facile spray-drying method and subsequent annealing treatment under N2 atmosphere, which are subsequently wrapped by graphene oxide (GO) to form the porous NiO/CNT/GO microspheres. Benefiting from abundant pores distributed between NiO nanoparticles and CNT, porous NiO/CNT/GO microspheres exhibit a good cycling stability (333.6 mA h g−1 after 1000 cycles at 2000 mA g−1). Thanks to CNTs distributed inside the microspheres and GO that provides support for microspheres, porous NiO/CNT/GO microspheres show a high rate performance (445.1 mA h g−1 at 5000 mA g−1). This work provides an approach for the synthesis of high-performance lithium-ion battery anode materials, and the synthesis of porous NiO/CNT/GO microspheres plays a very important role in promoting applied physics, which has brought vitality to physics.

Rambutan-like Ni0.5Zn0.5Fe2O4 nanospheres with tunable N-doped carbon shell as anode materials for high performance lithium-ion batteries

Multi-metal oxides have abroad application prospects as anode materials in lithium-ion batteries (LIBs) due to their adjustable chemical composition and plentiful active sites. In this study, rambutan-like Ni0.5Zn0.5Fe2O4 nanosphere are prepared by incorporating Zn into NiFe2O4, using a self-templating solvothermal technique. Then, Ni0.5Zn0.5Fe2O4@ N-doped carbon (NC) shell materials with different thickness of NC shell are obtained via coating different amount of dopamine followed by carbonization. As a LIBs anode material, the effects of NC shell thickness on electrochemical properties are discussed, and the Ni0.5Zn0.5Fe2O4@NC with 15 nm NC shell delivers 953.6 mA h g−1 specific capacity after 400 cycles at a current density of 1 A g−1, while the reversible capacity reaches 1124.3 mA h g−1 at the current of 0.1 A g−1. These results confirm that the appropriate NC shell thickness can effectively buffer the volume change and improve the electronic conductivity, accordingly improve the capacity and cycle stability of the electrode material. Furthermore, LiCoO2//Ni0.5Zn0.5Fe2O4@NC lithium-ion full cells are successfully assembled, and the electrochemical evaluation results demonstrate that they exhibit excellent lithium storage performance and promising application prospect.

Bimetallic zinc-cobalt sulfides embedded within N, S-codoped hollow carbon polyhedra for superior lithium-ion batteries

Binary transitional metal sulfides, as the anodes for lithium-ion batteries, have attracted increasing attention due to their high specific capacity, low cost, and environmental benignity. However, their relatively large volume variation and inferior reaction kinetics always result in unsatisfactory electrochemical performance. Herein, an approach is presented to facilely fabricate Zn-Co-S nanoparticles embedded in N, S-codoped carbon polyhedra (Zn-Co-S@NS-CP) using dopamine-coated metal–organic-frameworks as sacrificial precursors. During pyrolysis process, Co2+/Co3+ is introduced to ZnS lattice by partially substitution of Zn2+, and the Zn-Co-S nanoparticles are evenly anchored close to sulfur sites in the porous hollow carbon shell. The as-synthesized product inherits a unique hierarchical structure with interconnected conductive network. As a result, the optimized Zn-Co-S@NS-CP exhibits excellent lithium storage performance, including a high reversible capacity of 740 mAh g-1 at a current density of 1.12 Ag-1 as well as superior cyclic stability. Meanwhile, a notable capacity increasement upon cycling is observed, which can be ascribed to the phase separation of the lithiated products, creating more reactive sites and promoting lithium ion transportation as well as the reversible growth of polymer layer over the electrodes, further facilitating the capacity increment in the long-term cycling.

Preparation and lithium-storage performance of (Ti1−x,Vx)3C2 MXene solid solutions

Two-dimensional Ti3C2 MXene shows excellent lithium-storage performance as an anode of lithium-ion batteries. The replacement of Ti with V can enhance the lithium-storage performance, but decrease the stability of Ti3C2 MXene. To understand the impact of V replacement, in this study, a series of (Ti1−x,Vx)3C2 (x = 0, 0.1, 0.2…0.6) MXene solid solutions were prepared. The stability and lithium storage performance of the MXene solutions were investigated. The precursors to make (Ti1−x,Vx)3C2 MXene were MAX phase solid solutions of (Ti1−x,Vx)3AlC2, which were made from TiH2, V, Al and C powders at 1400 °C for 2 h under Ar atmosphere. Because of the replacement of > 60 at% Ti by V destroys the stability of the (Ti1−x,Vx)3AlC2, the MAX solid solutions with x ≤ 0.6 were synthesized in this study. (Ti1−x,Vx)3C2 MXene was made from the corresponding MAX phases by the etching in mixed solutions of NaF + HCl. (Ti1−x,Vx)3C2 MXene (x = 0–0.4) were synthesized at 60 °C for 2 days, and the MXene (x = 0.5–0.6) were synthesized at 70 °C for 6 days. All (Ti1−x,Vx)3C2 solid solutions had better electrochemical performance than pure Ti3C2 MXene. Especially, (Ti0.7,V0.3)3C2 exhibited the best performance. The capacity of (Ti0.7,V0.3)3C2 was 183.5 mAh/g after 100 cycles at a current density of 500 mA/g, which was ∼4.3 times of the capacity of the pure Ti3C2 (42.2 mAh/g at 500 mA/g). This is the first report to clarify the effect of V replacement on the stability and lithium performance on (Ti1−x,Vx)3C2 MXene solid solution. This work is critical for the synthesis of novel MXenes and MAX phases. It provides a way to make a MXene that is very close to V3C2 MXene, which is theoretically predicted but cannot be made. This work is vital for the enhancement of MXenes’ electrochemical performance.

Honeycomb substrate carbon and nitrogen-doped coated carbon synergistically boost SnS/ZnS for efficient lithium storage

Metal sulfide has become an important anode electrode material for lithium-ion batteries due to its high theoretical specific capacity and low cost. In this work, nano-SnS/ZnS grown on a honeycomb substrate carbon were coated with nitrogen-doped carbon (EG@SnS@ZnS@N-C) by solvothermal and in situ thermal decomposition/sulfide reactions. Honeycomb carbon with good electrical conductivity and mechanical mechanism is loaded with SnS and ZnS with synergistic effects, combined with nitrogen-doped porous carbon with enhanced ion transport. These unique designs enable EG@SnS@ZnS@N-C to exhibit excellent lithium storage performance with a specific capacity of 880 mAh/g at 0.1 A/g and capacity retention of 98% after 100 cycles.

Recycling of spent lithium–ion battery graphite anodes via a targeted repair scheme

When lithium–ion batteries (LIBs) reach the end of their life, a lot of hazardous wastes will be generated. Unfortunately, the recovery of spent graphite (SG) anodes is always neglected despite the rather high production cost of battery–grade graphite. In this work, we for the first time propose a novel targeted repair scheme by systematically characterizing and analyzing the structure and composition of SG. The results show that the repair scheme achieves effective SG repair and the repaired graphite anode displays excellent lithium storage performance, which can be comparable to that of commercial graphite. In addition, the scheme is evaluated to reduce energy consumption by 79 % and harmful pollutant emission by 90 % as compared to previously reported solutions. Obviously, our work provides a feasible solution for the recovery of graphite anodes from spent LIBs by understanding the failure characteristics of graphite anodes.

Excellent lithium storage performance of bipyridinium-based polymerized ionic liquids as anode in lithium-ion batteries

For organic electrode materials, slow Li+ diffusion kinetics is a main obstacle to the realization of high lithium storage capacity through a super-lithiation reaction. Here, bipyridinium-based polymerized ionic liquids (PILs) have been synthesized by the ionothermal trimerization of 1,1-dicyanomethyl bipyridinium bromide ILs in molten ZnCl2 matrix, and are used as an anode material for the first time. In which, the ionic chains are beneficial for fast Li+ diffusion, as well as the p-π resonance structure between methylene and aromatic ring helps the electron conduction. Electrochemical analysis shows PILs-400 can deliver 1201.5 mAh g−1 at 0.1 A g−1 and almost no capacity loss with the capacity of 873.6 mAh g−1 over 500 cycles at 2 A g−1. Theoretical calculation reveals that all functional groups of triazine, methylene, and bipyridinium have taken part in the redox reaction, and this reaction is associated with a three-step insertion process of 19 Li+ for each repetitive unit in forming Li19C14N5, along with the reversible formation of N-Li and C-Li bonds.

Hierarchical porous honeycomb microspheres assembled by MoS2 nanocrystals-embedded carbon nanosheets for high-performance lithium storage

Hierarchical porous honeycomb microspheres assembled by MoS2 nanocrystals-embedded carbon nanosheets are synthesized by constructing polystyrene (PS) sphere-embedded Mo-polydopamine organic/inorganic hybrid microspheres, followed by carbonization and sulfuration. The as-prepared composite is systematically studied by various material characterization techniques. It is found that the diameters of the microspheres and honeycomb pores are 3–5 μm and 200 nm. The specific surface area reaches 150.8 m2 g−1. MoS2@honeycomb carbon microsphere anode can achieve outstanding rate performance (237 mAh g−1 at 10 A g−1), high specific capacity and stable long-term cycling performance (reversible capacity of 1199 mAh g−1 at 0.1 A g−1 after 120 cycles, 599 mAh g−1 at 2 A g−1 after 300 cycles with capacity decay rate of 0.07 % per cycle, 495 mAh g−1 at 5 A g−1 after 500 cycles). The high reversible capacity is mainly derived from conversion reaction of MoS2 and lithiation reaction of S, as revealed by the analyses on the rate discharge curves. Kinetic measurements and ex-situ characterization further demonstrate the fast and stable Li+ diffusion, low impedance, strong capacitive effect and robust composite structure. The assembled full cell exhibits a reversible capacity of 209.7 mAh g−1 after 1880 cycles at 5 A g−1 and can power a red LED lamp. Overall, the excellent lithium storage performance manifests the significant potential of this MoS2 composite in high-performance lithium-ion batteries.

Research on 3D network in-situ grown NiCo2O4 nanowire arrays construction and its energy storage performance

In this paper, NiCo2O4 nanowire arrays are synthesized on 3D NF skeleton by a one-step hydrothermal method and used as anode materials for lithium-ion batteries (LIBs). Dense nanowire arrays are grown in situ on NF skeleton, cross-linked and constructed into 3D network structure. As an anode, it exhibits excellent electrochemical properties. The initial discharge capacity of NiCo2O4/NF is as high as 1316 mAh g−1 at a current density of 0.2 A g−1, and the specific capacity of 790 mAh g−1 can be maintained after 200 cycles. And NiCo2O4/NF can also maintain a specific capacity of 580.37 mAh g−1 at a current density of 1 A g−1 in the rating performance. And transfer resistance after 200 cycles reduced by 53.5%,which shows a tendency to decrease during the reaction process and accelerates the rate of Li+ transfer, improved battery cycling performance. The excellent lithium storage performance is attributed to the high aspect ratio of the nanowires themselves and the stable 3D network structure, which not only facilitates the rapid transfer of substances and diffusion of Li+, but also alleviates the volume change during the charge/discharge cycle. The band gap of NiCo2O4 can be obtained as 0.671 eV by first nature principle calculation, the electrons readily jump from the valence band to the conduction band and have good conductivity. And the diffusion potential barrier is 0.4 eV, which is easily overcome in the experiment and facilitates the transport of lithium ions.

Surface-modification-assisted synthesis of in-situ graphene-doped carbon substrate coated silicon nanoparticles for boosting lithium storage performance

Improving the electrical conductivity and structural integrity of Si/C anodes is of great concern for lithium-ion batteries which can be effectively achieved by doping graphene. However, it is difficult to achieve graphene-doped Si/C composites with good interface contact and conductive architecture. Herein, an in-situ graphene-doped carbon coated silicon nanoparticles (SiNPs) with multilayer architecture is designed. SiNPs is firstly modified and coated by polymethyl methacrylate (PMMA) shell. Multilayer carbon architecture is constructed via co-pyrolysis method using PMMA and citric acid as carbon sources. It displays an excellent lithium storage performance with a reversible discharge capacity of 2117.5 mAhg−1 at 200 mAg−1. These impressive anodic properties are chiefly benefited from the ingenious carbon architecture coated SiNPs involving in-situ graphene with a strong interfacial bonding interaction. Overall, this investigation can not only broaden the application potential in LIBs for advanced Si/C anodes but also provide an alternative route on designing a graphene-related material.

F127/PDA dual-assisted fabricating high dispersed Ge nanoparticles /N-doped porous carbon composites with efficient lithium storage

Nanocrystallization and carbon composite are effective methods to solve the mechanical instability and low conductivity of Ge-based anode materials. In this work, a meaningful phenomenon is discovered that F127 can effectively disperse GeO2 polycrystalline particles, which facilitates the formation of Ge nanoparticles embedded in N-doped carbon (Ge/N-C) composites. Polydopamine (PDA) has cross-linking effect, effectively alleviating the reaggregation of GeO2 nanoparticles, and its derived N-doped carbon ensures the uniform dispersion and independent structure of Ge nanoparticles. When assessed as anode material for lithium-ion batteries (LIBs), Ge/N-C composites exhibit a high discharge capacity of 1323 mA h g−1 in the second cycle at 0.2 A g−1 and 981 mA h g−1 after 100 cycles, with a capacity retention rate of 74%. Additionally, the composites show high-rate capability of 959 mA h g−1 at 2 A g−1. The excellent lithium storage performance is attributed to that the synergistic effect between three-dimensional carbon network structure and Ge nanoparticles, which provides stable mechanical structure and abundant redox sites, suppressing volume expansion and accelerating the electrochemical reaction kinetics.

Catalytic synthesis of 3D graphene nanostructures from biomass-based activated carbon with excellent lithium storage performance

3D multilayer graphene anode materials have shown great potential for energy storage devices due to their extraordinary structural stability combined with unique electrochemical characteristics. Herein, a facile strategy is proposed to synthesize 3D multilayer graphene nanostructures (M-GNS, M refers to graphitization catalyst) via microwave catalytic graphitization incorporated with liquid oxidation and thermal reduction using biomass-based activated carbon. The role of various graphitization catalysts on the characteristics and lithium storage performance of GNS were systematically investigated. Transmission electron microscopy results show that the use of Co led to the formation of multilayer graphene nanostructures with lower thickness compared to Ni and Fe. Various characterization techniques showed that the degree of graphitization in Co-graphitized activated carbon was lower, and the sample was dominated by smaller graphitic structures. When used as lithium-ion battery anode material, Co-GNS delivered superior rate capability (357 mAhg−1 at 5 Ag−1 after 1000 cycles with a capacity retention of ~94 %), and ultrahigh charge capacity (1695 mAhg−1 at 0.1 Ag−1), mainly owing to its thinner multilayer nanostructure.