Excellent Lithium-ion Storage Research Articles

A high-performance electrochromic battery based on complementary Prussian white/Li4Ti5O12 thin film electrodes

Electrochromic energy storage devices (EESDs) have a wide range of applications from static displays to building windows. However, it is a great challenge to assemble EESDs with both high performance of energy storage and electrochromism. In this work, we design a multifunctional EESD composed of a Li4Ti5O12 and a Prussian white. Li4Ti5O12 (E = 1.55 V vs Li/Li+) film with excellent lithium-ion storage performance is used as the anode, and Prussian white film (E = 3.2 V vs Li/Li+) as the cathode. Thanks to the complementary electrochromic behavior, the suitable redox voltage gap, and the intrinsic electrochemical stability of Li4Ti5O12 film and Prussian white film, the as-assembled EESD exhibits excellent electrochromic performances including broad optical modulation (55.3% at 529 nm), high coloration efficiency (170.1 cm2 C−1), and long-term cycling stability (retention of 95.8% of initial optical modulation after 1000 cycles). And the EESD shows high energy density of 127.2 mWh cm−2 and exceptionally high power density of 24 mW cm−2. This EESD with an output voltage of 1.5 V and Coulombic efficiency of 98.8% is promising for applications of electrochromic smart windows and static displays to significantly reduce their energy consumption.

One-step synthesis Nb2CTx MXene with excellent lithium-ion storage capacity

Nb2CTx MXene have received extensive attention due to their unique properties. However, it has always been a challenge to prepare Nb2CTx with excellent electrochemical performance in one step. In this work, we focus on developing intrinsic properties of Nb2CTx and directly preparing Nb2CTx with excellent lithium-ion storage capacity. A simple method of treating Nb2AlC with a mixed solution of HCl and LiF has prepared Nb2CTx with large interlayer spacing, good surface group configuration and pre-intercalated Li+. The Li+ ion storage capacity of Li-Nb2CTx was evaluated, and showed superior performance. At 0.05 A g−1, the specific capacity of Li-Nb2CTx electrode is 425 mAh g−1, and it is almost unchanged during 1000 h of charging and discharging. At 1.00 A g−1, the specific capacity is stable at 321 mAh g−1 during 800 cycles. Using a simple method to reasonably develop the intrinsic properties of Nb2CTx can directly obtain Li-Nb2CTx with excellent electrochemical properties. This result further enhances the application prospects of Nb2CTx in Li+ ion storage devices.

One-pot hydrothermal synthesis of N-rGO supported Fe2O3 nanoparticles as a superior anode material for lithium-ion batteries

Fe2O3 nanoparticles with a diameter of 60–70 nm are uniformly grown on the surface of N-rGO sheets via a facile hydrothermal method to form two-dimensional hybrid nanostructures. When evaluated as an anode material for lithium-ion batteries, this Fe2O3/N-rGO composite exhibits outstanding lithium storage performance, with a high reversible capacity of 1398 mAh g−1 at 0.5 A g−1 after 200 cycles and 652 mAh g−1 at 15 A g−1. The excellent performance of the Fe2O3/N-rGO hybrid can be attributed to the N-rGO sheets that benefit the fast transport of both lithium ions and electrons during electrochemical reactions; besides, the well-dispersed Fe2O3 nanoparticles and the flexible N-rGO substrate could effectively release the volume effect of the Fe2O3 during discharge/charge processes. Due to the unique two-dimensional hybrid nanostructure, Fe2O3/N-rGO composite shows significant pseudocapacitive behavior during discharge/charge processes, which partially accounts for the excellent lithium ion storage performance.

Self-template fabrication of multi-scaled ZnFe2O4 microspheres and their excellent lithium-ion storage properties

Self-template multi-scaled structure of ZnFe2O4 (ZFO) microspheres were synthesized through a solvothermal method, subsequently accompanied by various annealing processes. Specifically, hollow microspheres ZFO samples with modifiable internal structures (ranging from solid, core-in-hollow wall and double wall hollow) were synthesized differently through a mutual cooperation of inward-outward ripening mechanism by an anisotropic heating process during the calcination process. As active anodes for lithium-ion batteries (LIBs), that as-synthesized ZFO electrodes exhibited outstanding electrochemical properties and cyclic stabilities. Importantly, density functionally theoretical calculations have been investigated so as to understand the intermediate structures and electrochemical mechanisms of as-synthesized electrodes in the initial discharge process.

Fe3O4-Based Anodes with High Conductivity and Fast Ion Diffusivity Designed for High-Energy Lithium-Ion Batteries

A nitrogen and sulfur comodified graphene-coated sea urchin-like Fe₃O₄@C composite (Fe₃O₄@C@NS-rGO) is prepared by a hydrothermal method combined with a subsequent pyrolysis process. Using Fe₃O₄@C@NS-rGO as an anode in a lithium-ion battery, its reversible capacity reaches 532.5 mAh/g at 100 mA/g after 100 cycles. The lithium-ion full battery configurated by Fe₃O₄@C@NS-rGO and LiCoO₂ (Fe₃O₄@C@NS-rGOLiCoO₂) shows a working voltage of 3.25 V and an energy density of 232.1 Wh/kg (vs cathode). For the Fe₃O₄@C@NS-rGO composite, the sea urchin-like hollow structure makes it easier for the electrolyte to infiltrate, the holes can provide space for the volume change, and the one-dimensional rodlike structure around the sea urchin can shorten the transmission path of lithium ions and electrons. Moreover, the introduction of carbon and NS-rGO can increase the electron conductivity and also provide a double buffering effect on the volume change, especially heteroatom functionalization can also provide plentiful active sites for ion adsorption within the electrode, thereby giving excellent lithium-ion storage properties related to the reversible capacity, rate capability, and cycling performance. Such a concept of material design will open up a new strategy for preparing similar advanced anode materials toward high-energy storage systems.

Uniquely structured iron hydroxide-carbon nanospheres with yolk-shell and hollow structures and their excellent lithium-ion storage performances

Rationally designed transition metal compound-carbon composites have been widely studied as anode materials for high-efficiency alkali metal-ion batteries. In this study, iron hydroxide-carbon composite nanospheres with yolk-shell and hollow structures were successfully synthesized by a facile in-situ precipitation method using NaOH solution to confirm the effects of morphological control as well as compositing with carbon material on the electrochemical properties for lithium-ion storage. To prepare the yolk-shell and hollow structured iron nitrate-carbon composite precursor nanospheres, “vacuum heat-treatment” and “drop-and-dry” processes were employed, respectively. The graphitic carbon matrix and internal void space provided electronic conductivity and structural durability, respectively, during the repeated discharge and charge processes. Correspondingly, when applied as anodes for lithium-ion batteries, the yolk-shell and hollow structured iron hydroxide-carbon nanospheres delivered extraordinary rate performances and long-term cycle stabilities, revealing reversible discharge capacities of 504 and 442 mA h g−1 for 400 cycles at a current density of 5 A g−1, respectively. In addition, based on the results of various in-situ and ex-situ analyses, the reversible conversion reaction of iron hydroxide with lithium ions could be approximated by the following reaction: Fe(OH)3 + 3Li+ + 3e− ↔ Fe + 3Li(OH).

Ultrafast Li+ diffusion kinetics enhanced by cross-stacked nanosheets loaded with Co3O4@NiO nanoparticles: Constructing superstructure to enhance Li-ion half/full batteries

Novel CoNi binary metal oxide superstructures assembled with cross-stacked nanosheets (Co3O4/NiO/NC) have been successfully prepared by two-step thermal annealing process with CoNi-based and cyano-bridged coordination polymer (CoNiCP). Ascribing to the super decussate structure and as-obtained three-dimensional carbon conductive network, the obtained material exhibited excellent lithium-ion storage capacity including superior cycling stability and rate performance through facilitating the easy electron/ion transport. For example, CoNi binary metal oxide superstructures exhibit an excellent rate capacity of 493 mA h g−1 at 5.0 A g−1 and a long-lifetime cycling performance of 1390 mA h g−1 after 100 cycles at 0.2 A g−1. This strategy may pave a way for designing and preparing binary metal oxide superstructures materials with excellent electrochemical performance for lithium-ion battery by using coordination polymers as the sacrificial template.

General strategy for yolk-shell nanospheres with tunable compositions by applying hollow carbon nanospheres

Yolk-shell structure architecture is considered to be important in the fields that requires nanostructured designs such as energy storage systems. In particular, the internal and external structures, as well as compositions of yolk-shell materials, should be controllable in wide ranges to improve their properties for efficient applications in various fields. In this study, a new and general strategy tofabricate yolk-shell nanospheres with tunable compositions of yolk and shell parts under mild vacuum conditions is proposed. The melted metal salt is infiltrated in the void space of the hollow porous carbon nanospheres to form a yolk-shell structure under vacuum conditions, resulting in a yolk-shell structure with the configuration of a transition metal oxide (TMO)@void@C after a decomposition process under a vacuum. Yolk-shell nanospheres with configurations of TMO@void@TMO-C and TMO-C@void@TMO-C are also synthesized by controlling the vacuum degree for the infiltration of metal salt. Iron oxide, nickel oxide, and multicomponent materials are applied to confirm the applicability of the suggested method. This method facilitated in the tuning of the internal and external compositions was validated using various supporting data. The unique structured nanospheres with a configuration of FeOx-C@void@C showed an excellent lithium-ion storage performance.

Ni-Co Double Hydroxide Grown on Graphene Oxide for Enhancing Lithium Ion Storage

It still remains a major challenge to maintain the excellent lithium ion-storage performance of layered double hydroxide (LDH) for lithium ion battery anodes at high current density and long cycle ...

Efficient strategy for hollow carbon nanospheres embedded with nickel hydroxide nanocrystals and their excellent lithium-ion storage performances

In this study, an efficient supporting matrix for metal hydroxide, carbon hollow nanospheres are firstly applied for the synthesis of anode materials for lithium-ion batteries. Metal salt is infiltrated within the mesopores of carbon nanospheres, and then transforms into ultrafine metal hydroxide by in-situ precipitation. Immediate conversion reaction occurs between the ammonia solution and metal salt in liquid state to form ultrafine metal hydroxide. Hollow carbon nanospheres containing ultrafine Ni(OH)2 nanocrystals within the shell exhibit high structural stability during repetitive conversion reactions with Li-ions, as well as superior cycling and rate performances when comparing to those of bare Ni(OH)2 nanopowders.

Novel MXene-based hierarchically porous composite as superior electrodes for Li-ion storage

MXenes are widely investigated for electrochemical energy storage, sensors, and other fields, because of their excellent electrical conductivity and rapid ion transport. Nevertheless, the electrochemical properties and structural stability of MXenes are greatly restricted by the inherent self-restacking. Here we design and synthesize a series of hierarchically porous composites (C-Fe3O4/Ti3C2), where carbon-coated Fe3O4 (C-Fe3O4) acts as buttress to support the few-layered Ti3C2 MXene (f-Ti3C2) based on the hydrogen bonding interaction and Van der Waals force between the carbon coating layer and the f-Ti3C2. The self-restacking of f-Ti3C2 MXene and the sluggish reaction kinetics of Fe3O4 can be improved simultaneously when the C-Fe3O4/Ti3C2 composites are applied as anode for lithium-ion storage. The C-Fe3O4/Ti3C2 1:1 anode maintains ultrahigh reversible capacity of 1150 mAh g−1 at 1 A g−1 even after 1000 deep cycles, and 561 mAh g−1 at 5 A g−1, 340 mAh g−1 at 7 A g−1, showing excellent lithium-ion storage performance and superior structural stability that originated from the synergistic interaction between Fe3O4 and f-Ti3C2 MXene. The hierarchically porous composite opens up new possibilities in designing 2D MXene-based composites for catalytic, sensing, biomedical, energy storage materials.

Porous Ti2Nb10O29−x Microspheres Wrapped by Holey-Reduced Graphene Oxide as Superior Anode Material for High-rate Performance Lithium-ion Storage

Ti2[Formula: see text][Formula: see text] (TNO) is considered as a potential anode material due to its high capacity/power density and reliable safety. However, its poor electronic conductivity restricts its rate performance, which is important for its application in electric vehicles (EVs). In this study, we fabricated a hybrid of Ti2[Formula: see text][Formula: see text]/holey-reduced graphene oxide (TNOx/HRGO) by a two-step method. In the structure of TNOx/HRGO, TNOx microspheres with oxygen vacancies are wrapped by gossamer-like HRGO. The oxygen vacancies of TNOx and the high conductivity of HRGO can effectively enhance the electronic conductivity of the TNOx/HRGO hybrid, and the HRGO holes are beneficial for the transmission of lithium-ion ([Formula: see text]). The synergy effect of above features improves the rate performance of the TNOx/HRGO hybrid. In addition, the existence of HRGO can buffer volume expansion during the insertion processes of [Formula: see text], which can improve cyclic stability of the TNOx/HRGO hybrid. Consequently, the TNOx/HRGO electrode has excellent lithium-ion storage capacity, with high-rate performance (242[Formula: see text]mAh/g at 10∘C, 225[Formula: see text]mAh/g at 20∘C and 173[Formula: see text]mAh/g at 40∘C) and excellent cyclic stability (98.0% capacity retention after 300 cycles at 10∘C). This work reveals that TNOx/HRGO can be a potential anode material for high-rate-performance lithium-ion storage.

One-step gas-phase construction of carbon-coated Fe3O4 nanoparticle/carbon nanotube composite with enhanced electrochemical energy storage

Carbon nanotubes (CNTs) as superior support materials for functional nanoparticles (NPs) have been widely demonstrated. Nevertheless, the homogeneous loading of these NPs is still frustrated due to the inert surface of CNTs. In this work, a facile gas-phase pyrolysis strategy that the mixture of ferrocene and CNTs are confined in an isolated reactor with rising temperature is developed to fabricate a carbon-coated Fe3O4 nanoparticle/carbon nanotube (Fe3O4@C/CNT) composite. It is found the ultra-small Fe3O4 NPs (<10 nm) enclosed in a thin carbon layer are uniformly anchored on the surface of CNTs. These structural benefits result in the excellent lithium-ion storage performances of the Fe3O4@C/CNT composite. It delivers a stable reversible capacity of 861 mA ·h·g−1 at the current density of 100 mA·g−1 after 100 cycles. The capacity retention reaches as high as 54.5% even at 6000 mA·g−1. The kinetic analysis indicates that the featured structural modification improves the surface condition of the CNT matrix, and contributes to greatly decreased interface impendence and faster charge transfer. In addition, the post-morphology observation of the tested sample further confirms the robustness of the Fe3O4@C/CNT configuration.

Partial Atomic Tin Nanocomplex Pillared Few-Layered Ti3C2Tx MXenes for Superior Lithium-Ion Storage

HighlightsA facile NH4+ method was proposed to prepare Sn nanocomplex pillared few-layered Ti3C2Tx MXene nanosheets.The MXene nanosheets showed excellent lithium-ion storage performances among MXene-based materials, which can maintain 1016 mAh g−1 after 1200 cycles at 2000 mA g−1 and deliver a stable capacity of 680 mAh g−1 at 5 A g−1.

Engaging tailored capacity of layered WS2 via sulphur bonding coupled with polyetherimide (WS2@NC) nanocomposite for high power and improved lithium-ion storage

Layered transition metal sulfides have drawn great research attention due to their excellent properties for energy storage and conversion devices. However, there is a need to innovate effective approaches to enhance the performance of metal sulfides for modern energy storage devices. Herein, a rational surface engineering strategy was adapted to design tungsten disulfide nanosheets coated polyetherimide (WS2@PEI) nanocomposite by facile sol-gel method combined with a subsequent pyrolysis. The WS2@NC nanocomposite exhibits excellent lithium-ion storage properties as compared to pristine WS2 nanosheets. The origin of enhanced performance of WS2@NC nanocomposite is carbon-sulphur (C–S) bonding with WS2, offered by thermally stable polyetherimide (N–C). The increased strength of charging is subjected to C–S and N–C bindings, which significantly enhanced the active sites and defects in WS2@NC nanocomposite framework. The thin porous carbon layer provided elasticity to control the volume expansion during the lithium ions (Li+) insertion/deinsertion, while nitrogen and sulphur components offered more active sites and defects in the nanocomposite for reversible adsorption of Li+ ions. Thus, the WS2@NC nanocomposite could deliver high reversible specific capacity of 712 mAh g−1 at 0.1 A g−1 after 100 cycles and 417.6 mAh g−1 even at high current density of 0.8 A g−1 with 99% average coulombic efficiency.

Ionic liquid electrodeposition of Ge nano-film on Cu wire mesh as stable anodes for lithium-ion batteries

Germanium-based materials as anode can improve the capacity of lithium-ion battery because of its excellent lithium-ion storage ability. But the application of Ge anode is hampered by the huge volume variation during de/lithiation processes. Herein, a Ge/Cu wire mesh (Ge/Cu-WM) electrode is prepared by ionic liquid electrodeposition, where the Ge nano-film is deposited on Cu wire mesh. The unique structure of Ge/Cu-WM electrode not only buffers the volume expansion but also enhances electron migration and electron transport during lithiation. The Cu3Ge is observed by XRD, which confirms that the Ge nano-film tightly attach to the Cu wires. All structural properties give the electrode excellent electrochemical performance, where a capacity of 633 mAh/g after 100 cycles at 0.1 C is obtained. The reasonable structure and improved cycling stability make Ge-based anodes highly attractive for lithium-ion battery applications.

Three-dimensional porous pitch-derived carbon coated Si nanoparticles-CNT composite microsphere with superior electrochemical performance for lithium ion batteries

Although silicon has attracted attention as a promising anode material for lithium ion batteries due to its high theoretical capacity and relatively low discharge potential, the issue of large volume expansion and contraction during its de-/alloying reaction with Li has resulted in the development of nanostructured electrode design and coating methods using suitable carbon sources to improve the stability of the electrode. Pitch is regarded as an attractive carbon coating source owing to its mesophase characteristics, high mechanical strength, and electrical conductivity. In this study, three-dimensional porous pitch-derived carbon coated Si nanoparticles-carbon nanotube (Si-CNT@PC) composite microspheres were successfully synthesized by spray pyrolysis and a following pitch infiltration process. Uniformly distributed Si nanoparticles, acid-treated multiwall CNTs, and polystyrene (PS) nanobeads enabled the formation of porous structured Si-CNT composite microspheres by spray pyrolysis. Uniform infiltration of pitch dissolved in tetrahydrofuran followed by a carbonization process resulted in Si-CNT@PC microspheres. The uniquely structured Si-CNT@PC microspheres exhibited superior electrochemical properties compared with Si-CNT microspheres not coated with carbon. The synergetic effects of carbon-coated Si nanoparticles, macroporous structure formed by decomposition of PS nanobeads, and the CNT backbone resulted in excellent lithium-ion storage performance of Si-CNT@PC microspheres. The discharge capacities of Si-CNT and Si-CNT@PC at a current density of 1 A g−1 for the 200th cycle were 51 and 1209 mA h g−1, respectively.

Robust C–S bond integrated graphdiyne-MoS2 nanohybrids for enhanced lithium storage capability

A novel Graphdiyne-Molybdenum disulfide (GDY-MoS2) hybrid nanostructure is successfully synthesized through in-situ method. The compactly contact through carbon–sulfur (C–S) bond between graphdiyne (GDY) and molybdenum disulfide (MoS2) effectively prevents the detachment problem and also provides effective electron transport paths between them. Highly conductive GDY layer not only acts as an electron collector, but also provides the volume expansion space for MoS2. And the large contact surface area of GDY and MoS2 can exceedingly shorten the diffusion distance of lithium-ion. As the synergistic results of the distinct hybrid structure, highly conductive GDY layer, as well as the robust interconnection, GDY-MoS2 (with 77.9 wt% MoS2) exhibits excellent lithium-ion storage performance (1463 mAh g−1 at 0.05 A g−1) and super cycling stability when serving as lithium-ion batteries (LIBs) anode.

Micron-scaled MoS2/N-C particles with embedded nano-MoS2: A high-rate anode material for enhanced lithium storage

Nanostructured molybdenum disulfide (MoS2) is successfully embedded in the N-doped porous carbon to form micro-sized MoS2/N-C particles via a simple one-pot solution reaction. Yolk, a biomass carbon source with rich nitrogen and oxygen, makes a success to the heteroatom self-doping. The obtained N-doped porous carbon coating layers largely improve the conductivity and electrochemical activity. Moreover, the unique structure of MoS2 nanodots embedded in the porous carbon effectively combines the advantages of nanoscale MoS2 and micron scale N-doped C, which addresses the issues of MoS2 in lithium ion batteries (e.g., poor conductivity, sulfur loss and easy conglomeration). Interestingly, MoS2/N-C composite shows the first discharge/charge capacities of 1002 and 724 mAh g−1 at 0.1 A g−1 and stabilizes around 805 mAh g−1 after 100 cycles. Especially, it still remains at 630 mAh g−1 even under 0.5 A g−1 after 500 cycles, exhibiting excellent lithium ion (Li+) storage and cycle-to-cycle durability. This desired performance of MoS2/N-C is mainly resulted from the unique embedded structure, which effectively improves ion/electron transportation, ensures high sulfur reservation and prevents the conglomeration or accumulation during lithiation/delithiation reaction.

New synthesis strategy for hollow NiO nanofibers with interstitial nanovoids prepared via electrospinning using camphene for anodes of lithium-ion batteries

This paper introduces a new synthesis strategy suitable for the one-step synthesis of hollow 1-dimensition nanostructures and highly desirable for the simple preparation of well-defined hollow nanostructures with high product yields using camphene. The viscosity gradient of the jet during the electrospinning results in the inward movement of the camphene. Subsequently, the sublimation of camphene generates internal hollow space without further processing. The resulting nanofibers exhibit a reversible discharge capacity of 956 mA h g−1 after 400 cycles when applied as anodes for lithium-ion batteries. The discharge capacities of the nanofibers are 1050, 1024, 937, 796, 643, and 483 mA h g−1 at current densities of 0.5, 1.5, 3.0, 5.0, 7.0, and 10.0 A g−1, respectively. The NiO nanofibers with hollow structure show high structural stability and shorten the Li+-ion diffusion pathway during cycles, which resulted in excellent lithium-ion storage properties.