Superior Lithium Storage Research Articles

Versatile by design: Hollow Co3O4 architectures for superior lithium storage prepared by alternative green Pechini method

Co3O4 open hollow structures were synthesized by a new green alternative of Pechini method that implies three simple steps: (i) an initial formation of Co2+- citric soluble coordination compounds, (ii) hydrothermal processing (180 °C) in the presence of fructose followed by (iii) air thermal processing of the as-obtained precursor. Benefiting from its exclusive structural features, this appealing hollow Co3O4 material demonstrated superior specific capacity, rate performance and cycling stability (specific capacity of 848 mA h g−1 at an applied C-rate of 0.5 C with a coulombic efficiency of 98% after 250 cycles) in comparison with multi-shelled hollow spheres obtained in the absence of citric acid (525 mA h g−1 with a coulombic efficiency of 97% recorded under the same conditions).

In-situ embedding cobalt-doped copper sulfide within ultrathin carbon nanosheets for superior lithium storage performance

Construction of well-defined hybrid composites consisting of transition metal sulfides and two-dimensional (2D) carbon nanosheets as high-performance anodes for lithium-ion batteries (LIBs) is of great significance but remains challenging. Herein, we have developed a novel strategy to in-situ fabricate a nanohybrid composites consisting of cobalt-doped copper sulfides nanoparticles embedded in 2D carbon nanosheets (2D Co-Cu2S@C) through a one-pot sulfurization of 2D nanosheet-like Co-doped copper-based metal-organic frameworks (MOFs) precursors. When applied as LIBs anodes, the as-prepared 2D Co-Cu2S@C composites could deliver a specific capacity of 780 mAh g−1 at 0.5 A g−1 after 300 cycles and a high-rate capability with 209 mAh g−1 at 5 A g−1, superior to most reported copper sulfide-based anodes. The exceptional performance could be attributed to the synergism of ultrathin structure (~4 nm), appropriate cobalt doping and strong carbon coupling, resulting in the shortened paths for Li+ transportation, enlarged exposing surface for Li+ adsorption, enhanced electric conductivity for charge transfer as well as robust mechanical property against volume expansion.

Sulfur-doped reduced graphene oxide/Sb2S3 composite for superior lithium and sodium storage

Graphene, with excellent electrical conductivity and high theoretical capacity, may be one of the promising anodes for rechargeable batteries. However, several drawbacks, such as low initial coulombic efficiency (ICE) and limited actual reversible capacity, hamper their further development. Herein, a sulfur-doped reduced graphene oxide (rGO)-based composite with low-content Sb2S3 is synthesized through in-situ sulfuration process, which can deliver excellent electrochemical performance (high reversible capacity of 997 mA h g−1 with ICE of 71.6% for lithium storage and 639 mA h g−1 with ICE of 63.9% for sodium storage at 100 mA g−1), much higher than those of sulfur-doped or bare rGO. According to the physical and electrochemical characterizations, the partial substitutions of C–O bonds with C–S in rGO can greatly reduce the irreversible consumption of lithium or sodium, the covalent-bonded sulfur dopants and the doped Sb2S3 nanoparticles are electrochemically active for reversible lithium and sodium storage, and also enhance the structure stability effectively, resulting in superior electrochemical performance.

Copper nanowires and copper foam multifunctional bridges in zeolitic imidazolate framework–derived anode material for superior lithium storage

Herein, a synthetic strategy for growing trimetallic zeolitic imidazolate framework (ZIF) polyhedrons on copper foam (CF) and interweaving with copper nanowires (CNWs) is proposed. Subsequently, in situ annealing under N2 atmosphere leads to the formation of multi-doped CNWs/Cu0.39Zn0.14Co2.47O4-ZnO/CF (CNWs/CZCOZ/CF). The unique structural characteristics of CNWs/CZCOZ/CF allow it to be directly assembled as a working electrode, without additional conductive additives or binders. When it's used as the lithium-ion battery (LIB) anode, this electrode exhibits a significantly high capacity of 2305 mAh g−1 at 0.1 A g−1 after 500 cycles. More importantly, kinetic analysis on the basis of cyclic voltammograms (CVs) indicates that the pseudocapacitive effect is the primary contributor to the high lithium storage capacity and also accounts for the exceptionally high rate capacity of 713 mAh g−1 even if the current density is at a maximum of 10 A g−1. Moreover, the superior battery performance originates from their advantageous structural diversity and unique compositional features, including synergistic effects among polymetallic components and two highly conductive substrates (CNWs and CF), forming unhindered paths for fast charge transfer.

Micron-sized SiO x /N-doped carbon composite spheres fabricated with biomass chitosan for high-performance lithium-ion battery anodes.

To achieve superior lithium storage performance, SiOx is usually designed into nanostructured SiOx/C composites by complex or expensive methods. Here, micron-sized interconnected SiOx/N-doped carbon (NC) microspheres composed of evenly dispersed SiOx nano-domains and NC have been fabricated by a scalable microemulsion method and following pyrolysis, using vinyltriethoxysilane and chitosan as precursors. The unique structure of the micron-sized SiOx/NC spheres leads to enhanced structural integrity and enables stable long-term cycling (800 cycles at 2 A g−1). Benefiting from the enhanced electron/Li+ diffusion kinetics originated from the unique structure and N-doping, SiOx/NC-2 presents considerable capacitive-controlled Li storage capacity, which leads to outstanding rate capability. Consequently, the assembled SiOx/NC-2//LiFePO4 full cell exhibits superior rate capability (106 mA h g−1 at 4C) and stable long-term cycling at 2C (102 mA h g−1 after 350 cycles). This work opens a new door for the application of chitosan in building micron-sized high-performance SiOx/C anode materials, and to some extent facilitates the recycling of waste seafood shells.

A new spinel high-entropy oxide (Mg0.2Ti0.2Zn0.2Cu0.2Fe0.2)3O4 with fast reaction kinetics and excellent stability as an anode material for lithium ion batteries.

It is well known that transition metal oxides (TMOs) have attracted extensive attention as promising anodes for next-generation lithium ion batteries (LIBs) owing to their low cost and high theoretical capacities. However, the huge volume changes upon lithiation/delithiation cycling gradually cause drastic particle pulverization in the electrodes, thus leading to fast capacity fading and limiting their practical applications. High-entropy oxides with enhanced electronic conductivity and multiple electrochemically active elements display stepwise lithium storage behaviors, thus efficiently alleviating the volume change induced electrode pulverization problem. Herein, we report the synthesis of a new kind of spinel (Mg0.2Ti0.2Zn0.2Cu0.2Fe0.2)3O4 material via a facile one-step solid state reaction method and subsequent high-energy ball-milling. When used as anodes for LIBs, the submicrometer-sized (Mg0.2Ti0.2Zn0.2Cu0.2Fe0.2)3O4 particles exhibit superior lithium storage properties, delivering a large reversible capacity of 504 mA h g−1 at a current density of 100 mA g−1 after 300 cycles, and notably an exceptional rate capacity of 272 mA h g−1 at 2000 mA g−1. Our work highlights that rational design of high-entropy oxides with different electrochemically active elements and novel structures might be a useful strategy for exploring high-performance LIB anode materials in next-generation energy storage devices.

Synthesis of monodisperse rod-shaped silica particles through biotemplating of surface-functionalized bacteria.

Mesoporous silica particles of controlled size and shape are potentially beneficial for many applications, but their usage may be limited by the complex procedure of fabrication. Biotemplating provides a facile approach to synthesize materials with desired shapes. Herein, a bioinspired design principle is adopted through displaying silaffin-derived 5R5 proteins on the surface of Escherichia coli by genetic manipulations. The genetically modified Escherichia coli provides a three-dimensional template to regulate the synthesis of rod-shaped silica. The silicification is initiated on the cell surface under the functionality of 5R5 proteins and subsequentially the inner space is gradually filled. Density functional theory simulation reveals the interfacial interactions between silica precursors and R5 peptides at the atomic scale. There is a large conformation change of this protein during biosilicification. Electrostatic interactions contribute to the high affinity between positively charged residues (Lys4, Arg16, Arg17) and negatively charged tetraethyl orthosilicate. Hydrogen bonds develop between Arg16 (OH), Arg17 (OH and NH), Leu19 (OH) residues and the forming silica agglomerates. In addition, the resulting rod-shaped silica copy of the bacteria can transform into mesoporous SiOx nanorods composed of carbon-coated nanoparticles after carbonization, which is shown to allow superior lithium storage performance.

Facile fabrication of graphitization-enhanced wrinkled paper-like N-doped porous carbon via a ZnCl2-modified NaCl-template method for use as an anode in lithium ion batteries

Wrinkled paper-like carbon was constructed by employing a ZnCl2-modified NaCl template method, which exhibits a superior lithium storage performance.

Novel agaric-derived olive-like yolk-shell structured MnO@C composites for superior lithium storage.

Unique hierarchical olive-like yolk-shell structured MnO@C composites were customized via an ingenious and effective biomass strategy. This structure, with internal void spaces, accommodated the volume variations of MnO, and the N-doped porous carbon shells ensured the rapid transport of Li+/electron species. When used as anodes for LIBs, ultrastable rate and cycling performances were obtained.

Post-annealing tailored 3D cross-linked TiNb2O7 nanorod electrode: towards superior lithium storage for flexible lithium-ion capacitors

TiNb2O7 anode materials (TNO) have unique potential for applications in Li-ion capacitors (LICs) due to their high specific capacity of ca. 280 mA h g−1 over a wide anodic Li-insertion potential window. However, their high-rate capability is limited by their poor electronic and ionic conductivity. In particular, studies on TNO for LICs are lacking and that for flexible LICs have not yet been reported. Herein, a unique TNO porous electrode with cross-linked nanorods tailored by post-annealing and its application in flexible LICs are reported. This binder-free TNO anode exhibits superior rate performance (~66.3% capacity retention as the rate increases from 1 to 40 C), which is ascribed to the greatly shortened ion-diffusion length in TNO nanorods, facile electrolyte penetration and fast electron transport along the continuous single-crystalline nanorod network. Furthermore, the TNO anode shows an excellent cycling stability up to 2000 cycles and good flexibility (no capacity loss after continuous bending for 500 times). Model flexible LIC assembled with the TNO anode and activated carbon cathode exhibits increased gravimetric and volumetric energy/power densities (~100.6 W h kg−1/4108.8 W kg−1; 10.7 mW h cm−3/ 419.3 mW cm−3), more superior to previously reported hybrid supercapacitors. The device also efficiently powers an LED light upon 180° bending.

Free-Standing SnO2@rGO Anode via the Anti-solvent-assisted Precipitation for Superior Lithium Storage Performance.

Metal oxides have been attractive as high-capacity anode materials for lithium-ion batteries. However, oxide anodes encounter drastic volumetric changes during lithium ion storage through the conversion reaction and alloying/dealloying processes, leading to rapid capacity decay and poor cycling stability. Here, we report a free-standing SnO2@reduced graphene oxide (SnO2@rGO) composite anode, in which SnO2 nanoparticles are tightly wrapped within wrinkled rGO sheets. The SnO2@rGO sheet is assembled in high porosity via an anti-solvent-assisted precipitation of dispersed SnO2 nanoparticles and graphene oxide sheets in the distilled water, followed by the filtration and post-annealing processes. Significantly enhanced lithium storage performance has been obtained of the SnO2@rGO anode compared with the bare SnO2 anode material. A high charge capacity above 700 mAh g−1 can be achieved with a satisfying 95.6% retention after 50 cycles at a current density of 500 mA g−1, superior to reserved 126 mAh g−1 and a much lower 16.8% retention of the bare SnO2 anode. XRD pattern and HRTEM images of the cycled SnO2@rGO anode material verify the expected oxidation of Sn to SnO2 at the fully-charged state in the 50th cycle. In addition, FESEM and TEM images reveal the well-preserved free-standing structure after cycling, which accounts for high reversible capacity and excellent cycling stability of such a SnO2@rGO anode. This work provides a promising SnO2-based anode for high-capacity lithium-ion batteries, together with an effective fabrication adoptable to prepare different free-standing composite materials for device applications.

Facile Synthesis of Flock‐Like V2O3/C with Improved Electrochemical Performance as an Anode Material for Li‐Ion Batteries

V2O3is considered to be a potential anode material due to its large specific capacity and rich resources. Herein, flock‐like V2O3coated with carbon is prepared through a facile and simple solvothermal method followed by annealing at a relatively low temperature. The structure of V2O3/C is composed of porous strips. Due to the unique morphology and structure, the V2O3/C anode material shows excellent electrochemical performance. It delivers a specific discharge capacity of 696 mAh g−1after 100 cycles, which is 95% of the specific discharge capacity (732 mAh g−1) after the sixth cycle. The V2O3/C anode material annealed at 360 °C (V2O3/C‐360) delivers 601 mAh g−1at a current density of 300 mA g−1after 500 cycles. It implies superior cyclic stability of V2O3/C‐360. In addition, the anode also shows excellent rate capability. Specific capacities of approximately 600, 420, and 300 mAh g−1are obtained at the current densities of 0.3, 2, and 5 A g−1, respectively. The large current contribution of the capacitive reveals favorable superior lithium storage kinetics. This anode material presents great application potential in high‐performance lithium‐ion batteries.

Boosting Superior Lithium Storage Performance of Alloy‐Based Anode Materials via Ultraconformal Sb Coating–Derived Favorable Solid‐Electrolyte Interphase

AbstractAlloy materials such as Si and Ge are attractive as high‐capacity anodes for rechargeable batteries, but such anodes undergo severe capacity degradation during discharge–charge processes. Compared to the over‐emphasized efforts on the electrode structure design to mitigate the volume changes, understanding and engineering of the solid‐electrolyte interphase (SEI) are significantly lacking. This work demonstrates that modifying the surface of alloy‐based anode materials by building an ultraconformal layer of Sb can significantly enhance their structural and interfacial stability during cycling. Combined experimental and theoretical studies consistently reveal that the ultraconformal Sb layer is dynamically converted to Li3Sb during cycling, which can selectively adsorb and catalytically decompose electrolyte additives to form a robust, thin, and dense LiF‐dominated SEI, and simultaneously restrain the decomposition of electrolyte solvents. Hence, the Sb‐coated porous Ge electrode delivers much higher initial Coulombic efficiency of 85% and higher reversible capacity of 1046 mAh g−1 after 200 cycles at 500 mA g−1, compared to only 72% and 170 mAh g−1 for bare porous Ge. The present finding has indicated that tailoring surface structures of electrode materials is an appealing approach to construct a robust SEI and achieve long‐term cycling stability for alloy‐based anode materials.

NaCl‐Templated and Polyvinylpyrrolidone‐Assisted Fabrication of a MnO/C‐rGO Composite as a High‐Capacity Anode Material for Li‐Ion Batteries

A 3D hierarchically‐heterostructured manganese oxide/pyrolytic carbon and reduced graphene oxide composite material (MnO/PC‐rGO) is synthesized by the in situ redox reaction between a PC‐rGO carbon aerogel framework and KMnO4 solution, followed by heat treatment in an inert atmosphere. Herein, the 3D porous PC‐rGO carbon aerogel is prepared via crystal sodium chloride (NaCl)‐templated and polyvinylpyrrolidone (PVP)‐assisted freeze drying in the presence of graphene oxide (GO) and high‐temperature pyrolysis. As an anode material for lithium‐ion batteries, this composite exhibits a high charge capacity of ≈1030 mAh g−1 at 100 mA g−1 and 515 mAh g−1 at 2000 mA g−1. After cycling at 500 mA g−1 for 200 cycles, the capacity retention is ≈70%, demonstrating much superior lithium storage performance over the MnO/PC composite prepared under similar conditions. The superior electrochemical performance is ascribed to its good electrode kinetics behavior and the supernumerary capacity contribution of the PC‐rGO carbon framework due to the presence of rGO in the composite. As a synergic carbon support, the rGO can not only increase the specific capacity and rate capability but also improve the cyclability due to the enhanced electrical conductivity and the buffering effect of the flexible PC‐rGO against a large volume change during cycling.

Hierarchical MoS2/N-doped carbon nanobelts assembled by interlaced nanosheets as high performance Li-ion battery anode

MoS2-based composites with various hierarchical structures have received tremendous attention owing to their superior lithium storage performance. Herein, a simple synthesis strategy for the construction of hierarchical MoS2/N-doped carbon (MoS2/N–C) nanobelts via a facile hydrothermal method followed by carbonization without any extra assistance of hard templates is reported. The one-dimensional hierarchically mesoporous architecture is assembled by plenty of interlaced nanosheets, which ensures effective Li+ diffusion and good structural stabilization during the electrochemical reaction. Meanwhile, the N-doped carbon closely integrated with MoS2 nanosheets could offer a conductive network for fast electron transport. As a result, the MoS2/N–C nanobelts exhibit a high reversible capacity of 901 mA h g−1 after 100 cycles (at 100 mA g−1), eminent rate capability and cycling performance when used as anode materials for Li-ion batteries. The design concept reported in this work may open a simple avenue to construct hierarchical mesoporous architectures for enhanced lithium storage.

Polypyrrole-derived nitrogen-doped carbon coated hierarchical MnO porous microspheres for highly reversible lithium storage

Manganese monoxide (MnO) has emerged as a promising anode material in lithium-ion batteries (LIBs) due to its large lithiation capacity, low voltage hysteresis and environmental friendliness. In this work, we have developed the nitrogen-doped carbon coated MnO porous microspheres (MnO@NC), which consist of small nanocrystals with interparticle mesopores via a self-templated solvothermal synthesis and subsequent in-situ pyrolysis of polypyrrole precursors. By virtue of the conductive outer layer of nitrogen-doped carbon (NC) and the abundant inner mesopores, the hierarchical MnO@NC porous microspheres manifest the superior lithium storage properties as anode for LIBs. In detail, the optimized MnO@NC electrode delivers a high initial discharge capacity of 1037 mAh g−1 at 0.2 A g−1, remains the discharge capacity of 890 mAh g−1 at 1A g−1 after 500 cycles, indicates the outstanding rate capability with a specific capacity of 450 mAh g−1 at 5A g−1.

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.

Engineering MoS2 Nanosheets Anchored on Metal Organic Frameworks Derived Carbon Polyhedra for Superior Lithium and Potassium Storage

Metal organic frameworks (MOFs) have exhibited promising potential as a new platform for the preparation of porous functional materials for energy storage application. Herein, we report an approach to synthesize ultrathin MoS2 nanosheets decorated cobalt nanoparticles-containing porous carbon polyhedral with dense nitrogen doped carbon nanotubes (CNTs) backbone, where the ZIF-67 is used as the carbon and nitrogen sources for the growth of CNTs and the self-template for the carbon polyhedron. The composite shows a unique structure in which ultrathin MoS2 nanosheets are uniformly coated on the ZIF-67 derived carbon polyhedron. Owing to the synergistic effect from composition, morphology, and robust hollow structure composed of interconnected nitrogen doped CNTs networks and cobalt particles, the resulting ZIF-67-C@MoS2 nanocomposites display high specific capacity of 568.5 mAh g-1 at a current density of 0.2 A g-1, superior rate capability (291.9 mAh g-1 at 5 A g-1), and excellent cycling stability for over 500 cycles as lithium ion batteries anodes. The material also exhibits superior performance as new anodes for potassium ion batteries. The results provide a facile strategy for large-scale synthesis of high performance anode materials through low cost perspective and new insights for designing MOF-derived functional materials with unique structures for energy storage.

Ultrasmall metal oxide nanocrystals embedded in nitrogen-doped carbon networks based on one-step pyrolysis of bi-functional metallo-organic molecules for high-performance lithium-ion batteries

Commercial phthalocyanine dyes, including tin phthalocyanine and iron phthalocyanine, are employed as precursors to fabricate SnO2/Fe2O3 nanocrystals embedded in carbon framework by simple one-step in-situ pyrolysis. Phthalocyanine dyes are typical metallo-organic molecules incorporating N-containing conjugated organic shell and single metal atom core (Sn or Fe here), which can serve as the resources of both N-doped porous carbon and SnO2/Fe2O3 nanocrystals. Meanwhile, electronegative N atoms combined with rigid conjugated organic ligands is helpful for restricting the aggregation of metal ions during carbonization, leading to the generation of ultrasmall SnO2/Fe2O3 nanocrystals embedded in amorphous carbon framework (denoted as SnO2/N-PC and Fe2O3/N-PC). The obtained SnO2/N-PC and Fe2O3/N-PC have stable carbon continuous phase, ultrasmall and well-distributed metal oxide nanocrystals and porous skeleton, and then display superior lithium storage performance. SnO2/N-PC delivers high initial discharge and charge capacities of 1654 mAh g−1 and 1084 mAh g−1; after cycling for 200 times, it retains a reversible capacity of 775 mAh g−1, which is nearly 80% against the capacity of the second cycle. Fe2O3/N-PC presents high reversible capacity of 1123 mAh g−1 after 136 cycles at 200 mA g−1, and 612 mAh g−1 after 200 cycles at 1 A g−1.

Few-layer MoS2 nanosheets anchored by CNT network for superior lithium storage

A novel self-assembled porous network of carbon nanotubes (CNTs) attached to molybdenum disulfide (MoS2) nanosheets is prepared via a one-step atmospheric pressure chemical vapor deposition (APCVD) method. The conventional APCVD method cannot be used to uniformly deposit three-dimensional (3D) structures. Instead, an alternative method is used to overcome the disadvantage of conventional APCVD, whereby molybdenum oxide (MoO3) is decomposed by a molybdate ion (MoO42−) using in situ sulfuration. The synergy between the highly conductive CNT network and the layered MoS2 nanosheets contributes to the formation of high-efficiency ion/electron channels and improves the electrode durability and stability. The as-prepared C-MoS2/CNT composite exhibits both high rate stability and long-term capacity in lithium-ion batteries (LIBs). The C-MoS2/CNT electrode has a much higher initial discharge capacity of 1430 mAh g−1 at 100 mA g−1 and an impressive rate capability (885 mAh g−1 at 4000 mA g−1). Moreover, the C-MoS2/CNT composite also exhibits a long cycle life of 1260 mAh g−1 after 200 cycles at 500 mA g−1 and 1066 mAh g−1 at 1000 mA g−1 after 250 cycles. The mechanism and design strategy presented in this work may provide ideas for the development of other electrode materials.