High-performance Lithium-ion Battery Anodes Research Articles

MOF-derived Co3O4@rGO nanocomposites as anodes for high-performance lithium-ion batteries

MOF-derived Co3O4@rGO nanocomposites as anodes for high-performance lithium-ion batteries

Sandwich-like MoO3/ZnCo2O4 QDs@C@rGO/MoO3 hybrid nanosheets as high-performance anode for lithium-ion batteries

Transition metal oxides (TMOs) based compounds are recognized as high-energy anodes in next-generation lithium-ion batteries (LIBs) due to their extremely high theoretical capacity. However, the lower intrinsic conductivity, fast fading cyclic stability and dramatic volume expansion during discharge/charge processes greatly hinder the practical application of TMOs as anodes in LIBs. In this study, we have designed and constructed MoO3/ZnCo2O4 QDs@C@rGO/MoO3 (denoted as GMZCO) sandwich-structured hybrid nanocomposites via an effective route, and have proposed the formation mechanism of this unique nanostructured composite on the basis of the systematic results of the microstructures. Due to the unique sandwich structure and the synergistic enhancement effect of the ZnCo2O4 QDs, α-MoO3 and rGO, the as-constructed GMZCO exhibits the superior electrochemical performances when used as anode for LIBs. The obtained GMZCO can maintain high capacity of 1281 mAh g−1 at 0.2 A g−1 after 300 cycles, and can deliver as high as specific capacity of 913 mAh g−1 at 1 A g−1 after 500 cycles, revealing the higher capacity and excellent cyclic stability. What deserves to be mentioned most is that GMZCO can keep a capacity of 541 mAh g−1 after 1400 cycles even at higher current density of 3 A g−1, having outstanding rate capability. This work paves a novel approach for design TMOs with unique microstructures as a promising anode for the high-performances LIBs.

Mixed-metal MOF-derived Co–Mn–O hollow spheres as anodes for lithium storage

A Co–Mn–O/C composite is obtained by incorporating two metal ions from Co(Ac)2 and Mn(Ac)2 into a mixed-metal–organic framework (MOF) followed by high-temperature carbonization in air. The Co–Mn–O/C composite has a unique hollow-sphere structure with the shells constructed with Co–Mn–O grains embedded in an amorphous carbon matrix, which combines the advantage of efficient strain absorption and high conductivity. As a modulator, acetic acid has a large influence on the particle size and surface area of the Co–Mn–O/C hollow spheres that further affect their electrical properties, and an optimum Co:Mn ratio can result in greatly enhanced electrochemical performances. More importantly, the metallic Co nanoparticles in the Co–Mn–O/C composite also have the impact on adjusting the solid electrolyte interphase (SEI) layer, which helps in maintaining high morphological integrity and considerable electrochemical performance. At an optimum Co:Mn ratio, the Co–Mn–O/C electrode produces outstanding performance in both cycle and rate tests. A high-rate capacity of 1088.5 mAh g−1 is observed after 600 cycles at 1000 mA g−1 and a capacity of 775.9 mAh g−1 is reserved even after the current density rise to 8000 mA g−1. The Co–Mn–O/C composite is expected to serve as a low-cost and high-performance anode for lithium-ion batteries.

MnxOy embedded within CNT supporting porous carbon for enhanced lithium storage

Achievement of improved structural stability and conductivity for Mn-based oxides is the crucial premise for them to be high-performance anodes of lithium-ion batteries due to their large volume effect and poor intrinsic conductivity. Herein, the lithium storage performance of the MnxOy nanoparticles containing dominant MnO and slight MnO2 and Mn3O4 has been significantly improved by embedding them into a CNT supporting porous carbon. This composite is therefore denoted as CNT/MnxOy/C. The comparison results of the electrochemical performance of thus CNT/MnxOy/C with CNT/Mn3O4 and pure Mn3O4 nanoparticles demonstrate that the well-designed synergistic effect of high conductive CNT support and flexible spongy porous carbon is responsible for its improved performance, which efficiently enhances not only the structural stability but also the electrochemical kinetics of the CNT/MnxOy/C. As a result, this CNT/MnxOy/C anode shows outstanding performance, obtaining high capacities of 936.5 and 410.5 mAh g-1 at 200 and 1000 mA g-1 after 260 and 800 cycles, respectively. Moreover, this strategy proposed here will be hopefully instructive in constructing other advanced metal oxide nanomaterials toward improved performance of lithium-ion battery anodes.

Synthesis and Electrochemical Performance of Electrostatic Self-Assembled Nano-Silicon@N-Doped Reduced Graphene Oxide/Carbon Nanofibers Composite as Anode Material for Lithium-Ion Batteries.

Silicon-carbon nanocomposite materials are widely adopted in the anode of lithium-ion batteries (LIB). However, the lithium ion (Li+) transportation is hampered due to the significant accumulation of silicon nanoparticles (Si) and the change in their volume, which leads to decreased battery performance. In an attempt to optimize the electrode structure, we report on a self-assembly synthesis of silicon nanoparticles@nitrogen-doped reduced graphene oxide/carbon nanofiber (Si@N-doped rGO/CNF) composites as potential high-performance anodes for LIB through electrostatic attraction. A large number of vacancies or defects on the graphite plane are generated by N atoms, thus providing transmission channels for Li+ and improving the conductivity of the electrode. CNF can maintain the stability of the electrode structure and prevent Si from falling off the electrode. The three-dimensional composite structure of Si, N-doped rGO, and CNF can effectively buffer the volume changes of Si, form a stable solid electrolyte interface (SEI), and shorten the transmission distance of Li+ and the electrons, while also providing high conductivity and mechanical stability to the electrode. The Si@N-doped rGO/CNF electrode outperforms the Si@N-doped rGO and Si/rGO/CNF electrodes in cycle performance and rate capability, with a reversible specific capacity reaching 1276.8 mAh/g after 100 cycles and a Coulomb efficiency of 99%.

Boron-Doped and Carbon-Controlled Porous Si/C Anode for High-Performance Lithium-Ion Batteries

Silicon is a promising anode material for next generation lithium-ion batteries due to its high capacity and low discharge potential. Commercial silicon anodes are normally integrated with high graphite content to overcome their low electrical conductivity and huge cycling-induced volume change. However, this weakens the high specific capacity advantage of the silicon anode. Herein, a facile method based on the dealloying reaction of Mg2Si with CO2 and B2O3 was demonstrated for the synthesis of porous boron-doped silicon with low carbon content (pBSi-LC). Furthermore, the pBSi-LC anode showed high initial Coulombic efficiency of 89.3%, excellent rate performance (reversible capacity of 842 mAh g–1 at a high current density of 5A g–1), and long cycle stability (reversible capacity of 860 mAh g–1 at a current density of 2 A g–1 after 250 cycles).

1-Aminopyrene-modified functionalized carbon nanotubes wrapped with silicon as a high-performance lithium-ion battery anode

Silicon (Si) is regarded as a great promising anode material for lithium-ion batteries (LIBs) due to its high theoretical capacity and low lithium storage potential. However, the practical application of pure silicon is greatly limited by its low electrical conductivity and large volume expansion. It is well known that the modification ofsilicon negative materials with carbon tubes is a good strategy to overcome the low conductivity and poor cycling stability of silicon anode. In this work, the APOCs@Si composite is successfully synthesized by 1-aminopyrene (AP) modified oxidized carbon nanotubes (OCs) compounded silicon nanoparticles under ultrasonication-stirring condition. The APOCs@Si electrode presents a considerable reversible capacity of 913.7 mAh·g−1 with a stable structure after 610 cycles at a current density of 0.5A g−1, and the first reversible capacity is 3543.0 mAh g−1 at 0.1A g−1. The physico-chemical properties indicate that the incorporation of AP and OCs builds the interwoven CNTs networks, which serve as a matrix to buffer the volume expansion of silicon and boost the electronic conductivity of the electrode, to achieve remarkable capacity and cycle performance of APOCs@Si electrode. These remarkable results have further showed AP modified OCs as a buffer matrix significantly improve the cycle performance of silicon anode materials.

MOF-derived MnO/C composites as high-performance lithium-ion battery anodes

MnO, a promising anode material, has been widely applied in lithium-ion batteries (LIBs) due to it being environmentally friendly, easy to synthesize, and low cost. However, the huge volumetric expansion and particle aggregation that takes place during the charge/discharge process seriously hinder its development. In this study, we fabricate MnO/C composite by pyrolysis metal-organic frameworks (MOFs), which have a porous carbon nanosheet structure that supports MnO nanoparticles. MOFs were chosen as their large interlayer spacing provides sufficient buffer room for the volumetric change of the MnO nano-components during the charge/discharge process, thereby ensuring the stability of the overall structure. This structure greatly improves the electrochemical performance of MnO, resulting in a 96% capacity retention rate after 1000 charge-discharge cycles under 2 A g1 current density.

Engineering hollow cobalt oxide nanospheres with porous carbon coating for stable lithium storage

• Carbon coating of hollow CoO nanospheres was designed as porous structure. • The well-designed configuration played a key role in electrochemical properties. • Structural stability and kinetics of the CoO@HPC was determined systematically. • The CoO@HPC exhibited standout lithium storage performance. Constructing a stable, stress-relieving configuration is imperative to achieve a reversible cobalt oxide (CoO) anode for high-performance lithium-ion batteries. Herein, we propose a porous carbon coated ultrafine CoO nanoparticles assembled hollow nanospheres (CoO@HPC). In thus configuration, the well-designed porous carbon coating has a significant superiority compared to the common carbon coatings without porous structures, that is, the porous carbon coating can not only better buffer the volume change of CoO using its spongy structure featured better flexibility and rich free space, but also accelerate the lithium-ions diffusion by right of its open tunnel-like structure. On this ground, the synergistic effect of porous carbon coating and hollow structure endows CoO@HPC with superior structural durability and improved electrochemical kinetics. In consequence, this CoO@HPC shows superior electrochemical properties, displaying 704 (close to the theoretical capacity of CoO (716 mAh g −1 )) and 426.4 mAh g −1 after 120 cycles at 200 and even 1000 mA g −1 , respectively. This work highlights the importance of rational structure design of carbon coating for preparing advanced lithium-ion battery CoO-based anodes.

Utilization of impurities and carbon defects in natural microcrystalline graphite to prepare silicon-graphite composite anode for high-performance lithium-ion batteries

Utilization of impurities and carbon defects in natural microcrystalline graphite to prepare silicon-graphite composite anode for high-performance lithium-ion batteries

Constructing a hierarchical Sb@C nanoarchitectures as free-standing anode for high-performance lithium-ion batteries

The free-standing Sb@C anode composites has been fabricated via a controllable “layer-by-layer” (L-B-L) assembly method. As an anode for lithium-ion batteries (LIBs), the as-prepared electrode exhibits remarkable electrochemical performance with a high capacity of 600 and 525 mAh g−1 at 200 and 500 mA g−1 after 300 and 400 cycles, respectively. Such excellent lithium storage properties are primarily benefited from the ultrafine Sb nanoparticles uniformly embedded in the 3D interleaved porous carbon network, which not only provides a fast conductive network but inhibits the volume expansion and agglomeration of Sb during the discharge/charge process. The alloy-model reaction mechanism and outstanding reversibility of the Sb@C anode were systematically investigated.

Facile fabrication of three-dimensional porous carbon embedded with SnO2 nanoparticles as a high-performance anode for lithium-ion battery

Facile fabrication of three-dimensional porous carbon embedded with SnO2 nanoparticles as a high-performance anode for lithium-ion battery

Flexible Fe3O4/PCNFs membrane prepared by an innovative method as high-performance anode for lithium-ion battery

Porous carbon nanofibers (PCNFs) of anchoring abundant oxygen-containing groups are prepared by simply calcining carbon nanofibers (CNFs) in air. And then the Fe(OH)3 nanoparticles with positive charges in aqueous solution can anchor on the surface of PCNFs by the mutual electrostatic force. Ultimately, Fe3O4/PCNFs nanocomposite is fabricated by subsequent hydrothermal reaction. The Fe3O4/PCNFs composite exhibit a high reversible capacity of 668.5 ​mA ​h ​g−1 at a current density of 0.5 ​A ​g−1 after 150 cycles, which has an improved capacity over the sum of that of single PCNFs (316.7 ​mA ​h ​g−1) and Fe3O4 nanoparticles (146.8 ​mA ​h ​g−1). On one hand, the abundant pores of PCNFs are beneficial to the transmission and diffusion of lithium-ions. On the other hand, PCNFs as a high conductive framework provide for high-speed electronic transmission. What's more, PCNFs can buffer the volume changes of Fe3O4 nanoparticles. In brief, the preparation method of anchoring oxygen-containing groups onto CNFs is simple but innovative, which avoids the use of strong corrosive acid or strong oxidant, and has been proved for the first time that the PCNFs can load abundant Fe3O4 nanoparticles and the electrochemical performance of Fe3O4/PCNFs is comparable with many other iron oxides/CNFs hybrids.

Flexible SnTe/carbon nanofiber membrane as a free-standing anode for high-performance lithium-ion and sodium-ion batteries

Flexible electrode plays a key role in flexible energy storage devices. The SnTe/C nanofibers membrane (SnTe/CNFM) with excellent mechanical flexibility has been successfully synthesized for the first time through electrospinning, and it demonstrates outstanding electrochemical performance as free-standing anode for lithium/sodium-ion batteries. The SnTe/CNFM electrode delivers a discharge capacity of 526.7 mAh g−1 at 1000 mA g−1 after 1000 cycles in lithium-ion half-cells and a discharge capacity of 236.5 mAh g−1 at 500 mA g−1 after 80 cycles in lithium-ion full-cells with a LiFePO4 cathode. Not only that, it shows a discharge capacity of 182.7 mAh g−1 at 200 mA g−1 after 200 cycles in sodium-ion half-cells and a high discharge capacity of 207.0 mAh g−1 at 500 mA g−1 after 50 cycles in sodium-ion full-cells with a Na0.44MnO2 cathode. Moreover, the prepared SnTe/CNFM exhibits good mechanical flexibility. The SnTe/CNFM can still return to its original state without any breakage after bending, curling, folding and kneading. These results indicate that SnTe/CNFM is expected to become one of the promising free-standing anodes for lithium/sodium-ion batteries.

Electrochemically converting micro-sized industrial Si/FeSi2 to nano Si/FeSi for the high-performance lithium-ion battery anode

Low-cost silicon (Si) feedstocks and a facile method to downsize the particle size are two determinants for the application of Si for the lithium-ion battery anode. Among various Si feedstocks, the industrial bulk ferrosilicon (b-Si/FeSi2) alloy is a promising Si resource, but decreasing the particle size and increasing the utilization of Si remain challenging. Herein, we report a self-driven alloying-electrochemical dealloying approach to converting the b-Si/FeSi2 to nano-sized Si/FeSi (n-Si/FeSi) in molten salts using Mg to extract one Si atom from one FeSi2 molecule by breaking down the FeSi–Si chemical bond and simultaneously forming Mg2Si. Subsequently, the obtained FeSi and Mg2Si are converted to nano Si and FeSi by electrochemically removing Mg from the Mg2Si anode to the cathode, making a circular use of Mg and increasing the electroactive Si content. Moreover, the polydopamine-coated n-Si/FeSi (n-Si/FeSi@C) anode exhibits a high capacity of 1449.7 mAh g−1 after 500 cycles at 0.4 A g−1, and an extremely stable reversible capacity of 846.8 mAh g−1 is retained even after 1500 cycles at 2 A g−1. Overall, this work provides an efficient method to convert industrial bulk Si/FeSi2 to nano-sized Si/FeSi by leveraging the chemical bonds of Fe–Si and Mg–Si.

In-situ liquid-phase transformation of SnS2/CNTs composite from SnO2/CNTs for high performance lithium-ion battery anode

SnS2/CNTs composite with hexagonal SnS2 nanosheet growing along carbon nanotube (CNTs) by C-S bonding is synthesized via in-situ sulfuration of prefabricated SnO2/CNTs in the liquid environment. When they are used as Li ion batteries (LIBs) anode materials, the SnS2/CNTs exhibits much better cycling and rate performances than that of SnO2/CNTs. Through in-situ XRD characterization, SnS2/CNTs electrode possesses an additional Li+ intercalation reaction besides conversion and alloying/dealloying reaction in the first cycle. Further analysis by density functional theory (DFT) computations finds that hexagonal SnS2 exhibits lower Li+ adsorption energies and migration barrier than tetragonal structured SnO2, suggesting that Li+ storage and transfer in the SnS2/CNTs electrode is much easier and faster than SnO2/CNTs. As a consequence, SnS2/CNTs composite is more favorable for Li+ storage and is a promising anode material for LIBs.

Iron Phosphide Confined in Carbon Nanofibers as a Free-Standing Flexible Anode for High-Performance Lithium-Ion Batteries.

Iron phosphide with high specific capacity has emerged as an appealing candidate for next-generation lithium-ion battery anodes. However, iron phosphide could undergo conversion reactions and generally suffer from a rapid capacity degradation upon cycling due to its structure pulverization. Chemomechanical breakdown of iron phosphide due to its rigidity has been a challenge to fully realizing its electrochemical performance. To address this challenge, we report here on an enticing opportunity: a flexible, free-standing iron phosphide anode with Fe2P nanoparticles confined in carbon nanofibers may overcome existing challenges. For the synthesis, we introduce a facile electrospinning strategy that enables in situ formation of Fe2P within a carbon matrix. Such a carbon matrix can effectively minimize the structure change of Fe2P particles and protect them from pulverization, allowing the electrodes to retain a free-standing structure after long-term cycling. The produced electrodes showed excellent electrochemical performance in lithium-ion half and full cells, as well as in flexible pouch cells. These results demonstrate the successful development of iron phosphide materials toward high capacity, light weight, and flexible energy storage.

Ternary Si–SiO–Al Composite Films as High-Performance Anodes for Lithium-Ion Batteries

Silicon (Si) is a promising anode material for lithium-ion batteries but has long been suffering from low conductivity, drastic volume change, poor cycling performance, etc. Adding SiO, Al, etc. to form Si-based binary composite films can improve some properties but have to give up others. Here, we prepared a ternary Si-SiO-Al composite film anode by adding SiO and Al together into Si using magnetron sputtering. This film has an extraordinary combination of conductivity, specific capacity, cycling stability, rate performance, etc., when compared with its binary and unary counterparts. While both SiO and Al can separately mitigate anode cracking resulting from the huge volume expansion during the lithiation/delithiation cycling process, the synergetic effect of adding SiO and Al together to form a ternary composite film can produce much better results. This film maintains an island structure that can efficiently buffer the volume expansion during the cycling process, giving rise to superior cycling performance and excellent rate performance. In addition, the cosputtered Al improves the electrical conductivity of the anode at the same time. This unique combination of anode properties, together with the low cost, suggests that the Si-SiO-Al composite film has the potential to be commercialized as a binder-free anode for lithium-ion batteries. This work also provides an efficient means to modulate the anode properties with more degrees of freedom.

Bamboo-like SiOx/C nanotubes with carbon coating as a durable and high-performance anode for lithium-ion battery

SiOx, as a high-performance anode for lithium-ion batteries, has gained extensive attention because of its high capacity and low cost, but its further commercial value is hindered by volume expansion and bad conductivity. Herein, we develop and fabricate a novel bamboo-like SiOx/C@C structure, which is similar to hollow nanotubes (NTs) separated by many continuous partitions, through the sol–gel method and polymer coating technology based on the polydivinylbenzene NTs. During the periodic lithiation-delithiation, this ingenious structure enables a self-buffering space for the expansion and prevents the electrolyte from directly contacting the interior of NT, thereby avoiding the accumulation of solid-electrolyte interphase (SEI) layer. Furthermore, the outer carbon coating transformed from the exterior polymer layer provides a directional mechanical constraint for the inward volume expansion while achieving at a high electron transfer rate. The as-designed bamboo-like architecture exhibits a large reversible capacity (702 mA h g−1 after 200 cycles at 100 mA g−1) and a durable cycle life (capacity of 511 mA h g−1 after 450 cycles at 500 mA g−1). There will probably be potential value in diverse energy storage materials by this unique and scalable bamboo-like structure.

Sb2S3 nanorods/porous-carbon composite from natural stibnite ore as high-performance anode for lithium-ion batteries

To avoid the high purity reagents and high energy consumption involved in the manufacturing of lithium-ion battery anode materials, Sb2S3 nanorods/porous-carbon anode was prepared by remodeling natural stibnite ore with porous carbon matrix via a simple melting method. Due to the nanostructure of Sb2S3 nanorods and synergistic effect of porous carbon, the Sb2S3 nanorods/porous-carbon anode achieved high cyclic performance of 530.3 mA·h/g at a current density of 100 mA/g after 150 cycles, and exhibited a reversible capacity of 130.6 mA·h/g at a high current density of 5000 mA/g for 320 cycles. This shows a great possibility of utilizing Sb2S3 ore as raw material to fabricate promising anodes for advanced lithium-ion batteries.