Superior Lithium Ion Storage Performance Research Articles

In-situ assembly of 3D VS2/Reduced graphene oxide with superior lithium ion storage performance: The role of heterojunction

VS2 is a potential anode material for lithium-ion batteries (LIBs) due to its advantageous properties. Herein, a novel three-dimensional (3D) VS2/reduced graphene oxide (rGO) heterostructure (VS2-rGO) was fabricated by in-situ assembly of caterpillar-like VS2 nanosheets on rGO. This 3D VS2-rGO with a well-defined heterojunction interface is engineered to mitigate the volumetric expansion of VS2 during Li + intercalation/deintercalation cycles. This optimized design promotes enhanced conductivity across the heterojunction, facilitating efficient electron and ion transport. The VS2-rGO electrode shows higher reversible capacity and better rate performance (644.02 mA h g−1 at 0.1 A g−1 after 140 cycles, 526.66 mA h g−1 at 2 A g−1) as compared to the pure VS2 electrode (433.69 mA h g−1 at 0.1 A g−1 after 140 cycles, 63.91 mA h g−1 at 2 A g−1). Ex-situ XRD analysis suggests that the Li + storage mechanism in the VS2-rGO electrode involves the initial intercalation, followed by intercalation and conversion. The lower Li + diffusion barrier within the VS2-rGO heterojunction (0.183 eV) compared to the VS2 layers (0.225 eV), as predicted by first-principles calculations, resulting the enhanced Li + transport kinetics and improved cycling performance of the VS2-rGO electrode material. This work offers novel perspectives for the influence of heterojunctions on LIBs.

Localized nitride strategy to construct interfacial and electronic modulated WO3/WN nanoparticles for superior lithium-ion storage

The interfacial effect is important for the tungsten trioxide (WO3)-based anode to achieve superior lithium-ion storage performance. Herein, the interfacial effect was constructed by in-situ surface direct nitridation reaction at 600 ℃ for 30 min of the as-synthesis WO3 nanoparticles (WO3/WN). X-ray photoelectron spectroscopy (XPS) analysis confirms evident chemical interaction between WO3 and WN via the interfacial covalent bond (WON). This WO3/WN anode shows a distinct interfacial effect for an efficient interatomic electron migration. Electrochemical kinetic analysis shows enhanced pseudocapacitance contribution. The galvanostatic intermittent titration technique (GITT) result demonstrates improved charge transfer kinetics. Ex-situ X-ray diffraction (XRD) analysis reveals the reversible oxidation and reduction reaction of the WO3/WN anode. The density functional theory (DFT) result shows that the evident interfacial bonding effect can enhance the electrochemical reaction kinetics of the WO3/WN anode. The discharge capacity can reach up to 546.9 mA h g−1 at 0.1 A g−1 after 200 cycles. After 2000 cycles, the capacity retention is approximately 85.97 % at 1.0 A g−1. In addition, the WO3/WN full cell (LiFePO4/C//WO3/WN) demonstrates excellent rate capability and capacity retention ratio. This in-situ surface nitridation strategy is an effective solution for designing an oxide-based anode with good electrochemical performance and beyond.

In Situ Hybridization Strategy Constructs Heterogeneous Interfaces to Form Electronically Modulated MoS2/FeS2 as the Anode for High-Performance Lithium-Ion Storage.

The interfacial effect is important for anodes of transition metal dichalcogenides (TMDs) to achieve superior lithium-ion storage performance. In this paper, a MoS2/FeS2 heterojunction is synthesized by a simple hydrothermal reaction to construct the interface effect, and the heterostructure introduces an inherent electric field that accelerates the de-embedding process of lithium ions, improves the electron transfer capability, and effectively mitigates volume expansion. XPS analysis confirms evident chemical interaction between MoS2 and FeS2 via an interfacial covalent bond (Mo-S-Fe). This MoS2/FeS2 anode shows a distinct interfacial effect for efficient interatomic electron migration. The electrochemical performance demonstrated that the discharge capacity can reach up to 1217.8 mA h g-1 at 0.1 A g-1 after 200 cycles, with a capacity retention rate of 72.9%. After 2000 cycles, the capacity retention is about 61.6% at 1.0 A g-1, and the discharge capacity can still reach 638.9 mA h g-1. Electrochemical kinetic analysis indicated an enhanced pseudocapacitance contribution and that the MoS2/FeS2 had sufficient adsorption of lithium ions. This paper therefore argues that this interfacial engineering is an effective solution for designing sulfide-based anodes with good electrochemical properties.

Ultrafast high-temperature sintering of high-entropy oxides with refined microstructure and superior lithium-ion storage performance

Ultrafast high-temperature sintering of high-entropy oxides with refined microstructure and superior lithium-ion storage performance

Zinc ion exchange assisted synthesis of R-TiO2@C hollow spheres with superior lithium-ion storage performance

Nanostructured anode materials hold the key to advance the performance of the corresponding lithium-ion batteries as advanced electrochemical energy storage devices. Here, we designed a zinc exchange assisted phase change strategy as an acid-free and well-controlled approach to successfully synthesize a kind of rutile phase TiO2 @C (R-TiO2 @C) hollow spheres with well-defined size by using SiO2 spheres as sacrificial templates. The exchanged zinc ions in an alcohol solvothermal reaction were considered as a phase transition medium to promote the formation of a high-quality rutile TiO2 crystal through a high temperature solid-state heat way. By this way, the final morphologies of rutile phase TiO2 nanocrystals were well controlled, and the rutile TiO2 phase transformation temperature was lower than that of conventional one-step high temperature calcination way (without zinc ions exchange). Note that it successfully avoided using acids as mediums to promote the formation of rutile phase TiO2 crystal in the nano process. Meanwhile, the carbon layer formed by a hydrothermal carbonization reaction not only provided self-supporting solid-state in situ reducing medium for Zn2+ to Zn vapor but also produced conductive porous carbon coating porous and robust R-TiO2 spherical shell with nanosized subunits. The reaction process and mechanism of zinc ions induced phase transformation were discussed. Benefiting from the nanoscale morphology-regulation and hollow structure with enhanced ability of ion and electron transfer as well as electrolyte transport, the resultant R-TiO2 @C hollow spheres can significantly promote Li ions storage and deliver a high reversible specific capacity of 115.6 mAh g-1 at 5.0 C over 1600 cycles. A typical electrochemical reaction on Li ions inserted into TiO2 crystal was simply elaborated as well. This work demonstrates its great potential for practical application in lithium-ion batteries.

Hollow multi-shelled spherical Co3O4/CNTs composite as a superior anode material for lithium-ion batteries

Hollow multi-shelled spherical Co3O4/CNTs composite was prepared by a facile MOF-assisted strategy by introducing carbon nanotubes (CNTs) directly into the precursor. The hierarchical porous structure of the obtained multi-shelled Co3O4 nanospheres can effectively alleviate volume change and facilitate the infiltration of electrolyte into the interior. The interconnected CNTs can reduce the electrochemical polarization by improving the conductivity of the body material. As an anode for lithium ion batteries, the as-synthesized Co3O4/CNTs composite exhibits superior lithium ion storage performance. A high reversible specific capacity of 653.1 mAh g−1 was obtained after 500 cycles at 1000 mA g−1, suggesting a significant inspiration for fabricating application for advanced electrochemical devices.

Nitrogen doped porous carbon with high rate performance for lithium ion storage

Amorphous carbon has been studied in anode electrode materials of lithium ion batteries (LIBs) due to its rich resources and adjustable structure. However, due to its low conductivity, it shows poor rate performance. In this work, amorphous nitrogen doped porous carbon (NDPC) was synthesized by salt template method using ionic liquid (C10H15N5) as sources of carbon and nitrogen. The structure characterization shows that there is an interaction between the introduction of nitrogen atoms and porous structure: nitrogen doping can promote charge transfer, and porous carbon structure can reduce the diffusion path of lithium ions. Therefore, the NDPC shows excellent lithium ion diffusion ability and good electronic conductivity. When NDPC is applied to the anode material of LIBs, it shows a superior lithium ion storage performance of 412 mA h g−1 after 200 cycles at a current density of 1860 mA g−1. The study provides favorable conditions for the development of carbon anode materials with in situ heteroatom doping and porous structure.

One-step synthesis of FeS nanoparticles embedded in nitrogen-doped porous carbon for improved lithium storage properties

• FeS nanoparticles embedded in N-doped porous C is prepared by one-step strategy. • The N-doped C can improve conductivity, introduce defects and more active sites. • The FeS/NC electrode displays superior lithium-ion storage performance. • The electrochemical reaction mechanism is studied by ex-situ XPS. The electrode materials with simple preparation methods, good electrochemical performance, and cheap cost have broad application prospects in the field of electrochemistry. Herein, we propose one-step method for the direct sulfuration of iron-phthalocyanine (FePc) to produce FeS nanoparticles embedded in nitrogen-doped porous carbon (FeS/NC). Introducing porous carbon materials into the FeS nanoparticles can significantly restrain the huge volume expansion and enhance electrical conductivity. Nitrogen doping can further improve the electrical conductivity and introduce defects in the carbon host. The results show that the FeS/NC-750 demonstrates a discharge capacity of 834 mA h g −1 after 100 cycles at 200 mA g −1 . The FeS/NC anode still has a high discharge specific capacity of 612.4 mAh g −1 even after 500 cycles at 1000 mA g −1 . The simple strategy provides an inexpensive and straightforward strategy for conversion of FePc into available FeS/NC anode materials, which presents that FeS/NC electrode has potential application value in lithium-ion batteries.

Facile fabrication of Si-embedded amorphous carbon@graphitic carbon composite microspheres via spray drying as high-performance lithium-ion battery anodes

Silicon-nanoparticle-embedded amorphous carbon-graphitic carbon composite microspheres (denoted as Si/AC@GC) with numerous empty voids are synthesized using a spray drying process. Spray dried composite microspheres consisting of Si nanopowders, dextrin, and iron salt are transformed to uniquely structured Si/AC@GC microspheres via one-step carbonization followed by acid etching. The in situ formation of graphitic carbon with high electrical conductivity within the Si-C composite at a low carbonization temperature (700 °C) is achieved by applying a metallic Fe nanocatalyst. The Si/AC@GC microspheres exhibit higher electrochemical properties than bare Si nanopowders and Si/amorphous carbon composite microspheres (denoted as Si/AC) with filled structures. The synergistic effects of structural merits owing to the spherical morphology with empty nanovoids for liquid electrolyte penetration and a graphitic carbon layer with high electrical conductivity result in the superior lithium-ion storage performances of Si/AC@GC microsphere. The composite-based electrode delivers a high reversible capacity of 803 mA h g−1 after 200 cycles at 1.0 A g−1, indicating long-term cycling stability. Even at 5.0 A g−1, the electrode exhibits stable reversible discharge capacity of 589 mA h g−1 without significant capacity loss.

Pseudo-capacitive and kinetic enhancement of metal oxides and pillared graphite composite for stabilizing battery anodes

Nanostructured TiO2 and SnO2 possess reciprocal energy storage properties, but challenges remain in fully exploiting their complementary merits. Here, this study reports a strategy of chemically suturing metal oxides in a cushioning graphite network (SnO2[O]rTiO2-PGN) in order to construct an advanced and reliable energy storage material with a unique configuration for energy storage processes. The suggested SnO2[O]rTiO2-PGN configuration provides sturdy interconnections between phases and chemically wraps the SnO2 nanoparticles around disordered TiO2 (SnO2[O]rTiO2) into a cushioning plier-linked graphite network (PGN) system with nanometer interlayer distance (~ 1.2 nm). Subsequently, the SnO2[O]rTiO2-PGN reveals superior lithium-ion storage performance compared to all 16 of the control group samples and commercial graphite anode (keeps around 600 mAh g−1 at 100 mA g−1 after 250 cycles). This work clarifies the enhanced pseudo-capacitive contribution and the major diffusion-controlled energy storage kinetics. The validity of preventing volume expansion is demonstrated through the visualized image evidence of electrode integrity.

Hierarchical goethite nanoparticle and tin dioxide quantum dot anchored on reduced graphene oxide for long life and high rate lithium-ion storage

The synergetic effect between two or more electrochemically active materials usually leads to superior lithium-ion storage performance. This work demonstrates a straightforward and effective approach to synthesize a reduced graphene oxide (RGO) encapsulated larger goethite (FeOOH) nanoparticles and smaller tin dioxide (SnO2) quantum dots hierarchical composite (SnO2@FeOOH/RGO). The synthesized SnO2@FeOOH/RGO composite exhibits encouraging lithium-ion storage capability than controlled SnO2/RGO and FeOOH/RGO samples with a stable specific capacity of 638 mAh·g−1 under a high current rate of 1000 mA·g−1 for 2000 continual cycles and good rate performance. The redox reaction between reductive metal-atoms or metal-ions and graphene oxide (GO) sheets guarantees an effective immobilization of corresponding nano-sized metal oxide and hydroxide crystals by the RGO framework. Furthermore, the engineered larger FeOOH crystals engage in lithium-ion storage and perform an ideal spacer between the restacked RGO sheets. Therefore, smaller SnO2 quantum dots’ inherent excellent rate capability is extensively promoted due to the improvement of electrolyte diffusion and electron transfer condition. The sample design and fabrication method in this work might be developed for broader applications.

Carbon nano-onion encapsulated cobalt nanoparticles for oxygen reduction and lithium-ion batteries

Cobalt nanoparticles encapsulated by ionic liquid assisted one-step carbonization, which exhibited high oxygen reduction reaction activity and superior lithium ion storage performance.

Superior Lithium Ion Storage Performance of LiCoO2 Cathode at 4.5 V Enabled by the Multiple Synergistic Effect of Nano-Silver

LiCoO2 is still the potential first choice of cathode for lithium ion batteries due to the superior tap density of 4.1 g cm−3 and high theoretical specific capacity of 274 mAh g−1. However, the reversible capacity and cycle performance are restricted due to structural instability at high voltage (≥4.5 V). In this work, the problem will be improved by multiple synergistic effect of nano-Ag. The flake-like LiCoO2/Ag cathodes are firstly synthesized by solid state reaction and the following calcination. The structural characteristics reveal that Ag nanoparticles with ca. 10 nm are uniformly embedded into LiCoO2 particles. The initial discharge specific capacity of LiCoO2 is increased by 12% by introducing nano-Ag at 100 mA g−1 (∼0.7C) between 3.0–4.5 V, and after 100 cycles, the discharge specific capacity is enhanced by 52%. Furthermore, when the current density is increased to 2000 mA g−1, the specific capacity retention of LiCoO2/Ag researches to 62%, higher than 52% of LiCoO2. The results clearly indicate that LiCoO2/Ag cathode exhibits excellent specific capacities, enhanced cycle stability and rate performances enabled by nano-Ag through enhancing Li ions diffusion, electron transport and improving structural stability.

Scalable One-Pot Synthesis of Hierarchical Bi@C Bulk with Superior Lithium-Ion Storage Performances.

Lithium-ion batteries (LIBs), the most successful commercial energy storage devices, are now widespread in our daily life. However, the lack of appropriate electrode materials with long lifespan and superior rate capability is the urgent bottleneck for the development of high-performance LIBs. Herein, a hierarchical Bi@C bulk is developed via a scalable pyrolysis method. Due to the ultrafine size of Bi nanoparticles and in situ generated porous carbon framework, this Bi@C anode evidently facilitates the diffusion of Li+/electron, availably inhibits the agglomeration of active nano-Bi, and effectively mitigates the volume fluctuation. This hierarchical Bi@C bulk exhibits stable cycling performance for both LIBs (256 mAh g-1 at 1.0 A g-1 over 1400 cycles) and potassium-ion batteries (271 mAh g-1 at 0.1 A g-1 for 200 cycles). More importantly, when coupled with a commercial LiCoO2 cathode, the assembled LiCoO2//Bi@C cells provide an output voltage of 2.9 V and retain a capacity of 202 mAh g-1 at 0.15 A g-1. Moreover, kinetic analysis and in situ X-ray diffraction characterization reveal that the Bi@C anode displays a dominated pseudocapacitance behavior and a typical alloying storage mechanism during the cycling process.

Superior lithium-ion storage performance of hierarchical tin disulfide and carbon nanotube-carbon cloth composites

Tin-based composites are promising anode materials for high-performance lithium-ion batteries (LIBs); however, insufficient conductivity, as well as fatal volume expansion during cycling lead to poor electrochemical reversibility and cycling stability. In this work, we demonstrate the lithium-ion storage behaviors of SnS2 anode material deposited on different electrode supports. The SnS2 grown on 3D hierarchical carbon nanotube-carbon cloth composites (SnS2-CNT-CC) shows superior capacity retention and cycle stability, compared to that on planar Mo sheets and carbon cloth. The specific capacity of SnS2 on Mo, CC, and CNT-CC is around 240, 840, and 1250 g−1, respectively. The SnS2-CNT-CC electrode outperforms in the cyclic performance and rate capability compared to other electrode configurations due to the multi-electron pathway and high surface area derived from 3D hierarchical CNT-CC electrode support. Furthermore, a significant decrease in the charge transfer resistance is observed by utilizing 3D hierarchical CNT-CC electrode support. The use of 3D hierarchical structures as electrode support could be the best alternative to enhance the electrochemical performances for the next generation LIBs.

Synthesis of a pomegranate shaped reduced graphene oxide stabilized secondary Si nanoparticles composite anode for lithium ion batteries

A 3D porous micro-size pomegranate shaped nano-silicon and reduced graphene oxide composite (Si/RGO-S) is synthesized in this work by spray drying and magnesiothermic reduction treatments of silicon dioxides (SiO2) nanospheres and few-layered graphene oxide sheets (GO). The SiO2 nanospheres convert to smaller Si secondary nanocrystals and GO sheets are deoxygenated to form a supporting RGO framework, respectively. Favorable void space is created between the secondary Si nanoparticles for the accommodation of the volume changes during lithium ion storage. The 3D porous RGO protecting skeleton not only improves the overall electronic and ionic conductivity, but also effectively immobilizes the inside Si nanoparticles. Under a current density of 500 mA g−1, the 3D Si/RGO-S composite exhibits a reversible capacity of 1200 mAh g−1 for 300 consecutive cycles, which is much higher than the controlled 2D sample (Si/RGO-F) prepared by a freeze drying and magnesiothermic reduction method as anode material for lithium ion batteries. The insight into the superior lithium ion storage performance of the Si/RGO-S has been given in this work.

Fibrous network of highly integrated carbon nanotubes/MoO3 composite bundles anchored with MoO3 nanoplates for superior lithium ion battery anodes

Fibrous network of highly-integrated CNTs/MoO3 composite bundle in which CNTs anchored with MoO3 nanoplates was prepared by electrospinning process and subsequent simple heat-treatment. By performing the pre-acid-treatments of both CNTs and PAN, dipole-dipole interactions and hydrogen bonding between CNTs and PAN could form MoO2(acac)2-PAN-CNTs complex in a solution, which allows for the formation of a stable jet during electrospinning. Notably, by selectively removing PAN in as-spun fibers during heat-treatment, a highly integrated CNTs/MoO3 bundle network anchored with MoO3 nanoplates was obtained. This unique CNTs/MoO3 percolation network makes it possible to achieve a superior lithium ion storage performance by improving electrical conductivity and structure stability. Thus, the unique nanostructure has high discharge capacities of 972mAhg−1 after 100 cycles at 1.0Ag−1 and 905mAhg−1 after 800 long-term cycles at 2.0Ag−1, when applied as anode materials for lithium-ion batteries. The discharge capacities of 980, 920, 819, 742, 599, 484, and 374mAhg−1 were observed at current densities of 0.5, 1.0, 2.0, 3.0, 5.0, 7.0, and 10.0Ag−1, respectively.

Encapsulating tin oxide nanoparticles into holey carbon nanotubes by melt infiltration for superior lithium and sodium ion storage

Design and development of alternative anode materials is of essential importance to power electronic vehicles and portable devices. As a promising candidate, tin oxide (SnO2) shows great potential for lithium and sodium storage due to its relatively high capacity and excellent safety. However, the SnO2 anode is suffering from its poor conductivity and large volume variation during charge/discharge process. Herein, a controllable and effective strategy is proposed by encapsulating SnO2 nanoparticles into the interior space of holey carbon nanotubes (hCNT). Such a conductive carbon nanotube networks could not only enhance the electronic conductivity of SnO2, but also provide abundant void space to accommodate the volume variation. As a result, the SnO2@hCNT electrode exhibits superior lithium and sodium ion storage performance. At a discharge current density of 100 mA g−1, the SnO2@hCNT could deliver reversible discharge capacity of 1192 mA h g−1 and 223 mA h g−1 for lithium and sodium ion storage, respectively. Even at high current density of 2000 mA g−1, the SnO2@hCNT also shows excellent rate performance and cyclic stability. Our results suggest that storing and transporting Li/Na ions in the interior space of hCNT should be one of the promising approaches to develop novel anode materials.

Popcorn-like niobium oxide with cloned hierarchical architecture as advanced anode for solid-state lithium ion batteries

The advancement of high-power solid-state lithium ion batteries (LIBs) is closely in connection with the breakthrough of electrode materials. In this work, for the first time, we report a popcorn-like niobium oxide with cloned hierarchical architecture via sacrificial puffed rice carbon (PRC) template and solvothermal method. The popcorn-like Nb2O5 (PL-Nb2O5) shows a tertiary hierarchical macrocellular structure with cross-linked 2D secondary Nb2O5 nanoflakes, which are composed of primary self-assembled Nb2O5 nanocrystals. Impressively, this exquisite hierarchical architecture offers continuous fast transport paths for ion/electron and improves the specific surface area & porosity, resulting in accelerated reaction kinetics and good compatibility with gel polymer electrolyte (GPE). Accordingly, the popcorn-like Nb2O5 electrode is endowed with superior lithium ion storage performance in gel polymer electrolyte with good high-rate capacities (126 mA h g-1 at 5C and 103 mA h g-1 at 10C) and stable long-term cycling performance (75 mA h g-1 after 1000 cycles at 5C). Our findings propose a new bioinspired template way for construction of cloned metal oxides architectures for solid-state energy storage systems.

Revealing the effect of cobalt-doping on Ni/Mn-based coordination polymers towards boosted Li-Storage performances

In this work, a nickel-based coordination polymer is synthesized through a facile microwave-assisted solvothermal method. Cobalt ions are further introduced by a cation-exchange process to construct the nickel-cobalt bimetallic coordination structure. This bimetallic coordination polymer (Co–Ni-BTC) exhibits substantially improved cycling performance than the single nickel coordination polymer (Ni-BTC) and previous Ni/Co-based coordination polymers with various organic ligands for lithium ion batteries. A reversible charge capacity of 1051 mAh g−1 is achieved at 100 mA g−1 after 300 cycles for Co–Ni-BTC, which is more than 4 times as large as that for Ni-BTC (258 mAh g−1) after same cycle number. The superior lithium-ion storage performance of the Co–Ni-BTC can be ascribed to its regular and porous structure inherited from the coordinated interaction between nickel/cobalt and 1,3,5-benzenetricarboxylic acid (BTC) and a highly reversible Li-reaction with the coordination polymer. The cobalt-doping is found to activate the electrochemical activity of nickel ions and facilitate the ion/electron diffusion process. The similar beneficial effect of Co-doping can also be applied to the Mn-BTC coordination polymer. These observations may shed lights on the design and development of new coordination polymer electrodes with large reversible capacities.