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A dual interface SiO x /C composite is prepared through a novel, facial, one-step route by redox reaction of organic carbon with silica precursor, using tetraethyl orthosilicate (TEOS) and sucrose as raw material, in which sucrose acts as both a reductant and coated carbon. HRTEM indicates that the composite has a dual interface structure with carbon coating layer and intermediate layer. Crystalline Si approximately 3 nm–20 nm in size is dispersed in amorphous silicon oxide matrix. The SiO x /C is utilized in LIB as anode material and exhibits a high reversible specific capacity of 755 mA h g−1 after 300 cycles at 100 mA g−1 with capacity retention about 91%. Such outstanding cycling stability can be ascribed to the intermediate layer and carbon scaffold, which serve as a buffering to relieve volume change of produced Si upon cycles. • SiO x /C composite with dual interface structure is fabricated by a facial, one-pot synthesis method. • Dual interface structure provides a strong buffering for volume change of SiO x /C. • The dual interface SiO x /C shows high capacity and outstanding cycling performance. • Structure and electrochemical performance analysis of SiO x /C are studied in detail. [ABSTRACT FROM AUTHOR]

Tin-based materials are considered to be next-generation anode materials for lithium-ion batteries (LIBs) due to their high theoretical capacity and safety, but their large volume expansion results in rapid capacity fading. In this work, the heterostructure of Sn|SnO 2 submicron particles supported by carbon fibers and amorphous carbon layers (CF/Sn|SnO 2 @C) is successfully synthesized by hydrothermal and thermal treatments. Sn|SnO 2 submicron particles are uniformly grown on CF and encased in the CF network. Herein, CF together with a layer of amorphous carbon not only buffers the volume change of Sn|SnO 2 to prevent its pulverization and dissolution but also improves the electric and lithium ionic transportation capabilities during the lithiation/delithiation cycle. The CF/Sn|SnO 2 @C film can directly act as a binder-free anode for LIBs, exhibits a stable capacity of 657.6 mAh g −1 at a current density of 0.1 A g −1 after 50 cycles and presents better rate capacities than the Sn|SnO 2 @C comparison sample. Taking advantage of the stabilization and conductive channels of CF, this work demonstrates potential applications in the preparation of CF-based, binder-free anodes for LIBs in which metal oxide submicron particles can be effectively supported by a CF network. [ABSTRACT FROM AUTHOR]

Cobalt sulfide (CoS) has a high theoretical capacity as an anode materials for lithium ion batteries (LIBs), however it suffers from poor cyclability and weak retention. Therefore, a lot of efforts have been devoted to overcome these defects. In this work, cobalt sulfide/carbon nanotubes (CoS/CNTs) nanocomposites were prepared by a simple and effective solvothermal method. The nanocomposites were constructed by CoS nanoparticles coated on the carbon nanotubes and the electrochemical performances of the CoS/CNTs nanocomposites were investigated as anode materials for LIBs. The results showed that the materials had superior cycle stability and kept a high discharge capacity of 780 mAh g −1 after 50 cycles at the current density of 100 mA g −1 . The excellent electrochemical performances are due to the good combination of the hybrid structure and better electron transportation originated from CNTs. The CoS/CNTs nanocomposites with excellent rate capabilities and super capabilities could be promising anode material for lithium ion battery. [ABSTRACT FROM AUTHOR]

Layered lithium-rich manganese-based materials with high voltage stability and high energy density are used to modify the surface of spent LiCoO 2 materials (LCO) for designing high-performance Li+-storage structures with high specific capacity and high voltage cycling stability. In this typical regeneration process, Mn2+, Co2+, Ni2+, and Li+ acetates were introduced as raw materials for coating Li 1.20 Mn 0.54 Co 0.13 Ni 0.13 O 2 (LLO) on the surface of spent LCO particles uniformly via a sol-gel method. The structural, morphological, and elemental-chemical-state characterisation results indicate that the recycled LLO@LCO materials exhibit a typical core-shell structure, with a layer-structured-Li 1.20 Mn 0.54 Co 0.13 Ni 0.13 O 2 layer ~ 10 nm thick as the high-voltage-stable-shell and a well-ordered layer-LiCoO 2 as the high-capacity-core. As expected, the regenerated LLO@LCO composites show an upgraded Li+-storage performance compared to bare LCO. The optimised LLO@LCO materials show an initial capacity of 197.1 mAh g−1 at 0.1 C, and ~ 95.8% retention after 100 cycles under 3.0–4.5 V at a rate of 1 C. All results indicate that this highly efficient, LLO assisted modification regenerate strategy can be easily extended to regenerate other spent cathodes to synthesise advanced energy storage materials with high voltage cycle stability and high specific capacity. • LLO was introduced for regenerating spent LCO. • LLO@LCO compounds were synthesized via sol-gel method. • Recycled LLO@LCO shows upgraded high-voltage stability. [ABSTRACT FROM AUTHOR]

CuO–Cu 2 O/graphene composite has been successfully prepared by the combination of a microwave-assisted process and subsequent annealing. X-ray diffraction and electron microscopy reveals that copper oxide nanospheres with a size of 120–200 nm are uniformly anchored on graphene nanosheets. The copper oxide nanospheres are composed of numerous CuO and Cu 2 O nanocrystals of ∼10 nm. These nanospheres are hollow and the thickness of the shells is around 50–70 nm. The CuO–Cu 2 O/graphene composite shows a highly reversible capacity and excellent rate performance as anode for Li-ion battery. The reversible capacity of the composite retains 487 mA h g −1 after 60 cycles at 200 mA g −1 . Even when cycled at various rate (200, 500, 1000, 2000, 5000 mA g −1 ) for 60 cycles, the capacity can recover to 520 mA h g −1 at the current of 200 mA g −1 . The enhanced electrochemical performances are ascribed to the hollow spherical architectures, excellent conductivity of graphene sheets, and possible synergistic effects between CuO, Cu 2 O and graphene that enhance the intrinsic properties of each component. [ABSTRACT FROM AUTHOR]

Mixed transition metal oxides have attracted much attention as anode materials for lithium-ion batteries because of their high theoretical capacity, low cost, and rich redox reaction. In this work, coralline-like FeMnO 3 anode materials are synthesized by a facile co-precipitation method and subsequent sintering in air. The influences of sintering temperature on the microstructure and electrochemical performance of the samples are investigated. The results demonstrated that with the increase of sintering temperature, the phase structure of the products changes from FeMnO 3 /Fe 2 O 3 /Mn 3 O 4 composites at 600 °C to pure phase FeMnO 3 at 1000 °C, accompanied with the size of the primary particle increasing from tens of nanometers to hundreds of nanometers. Discharge/charge performance tests indicated that the sample sintered at 600 °C presents the biggest fluctuation of capacity during cycling, while the sample sintered at 1000 °C gives a rather flat capacity during cycling; moreover, the pure phase FeMnO 3 at 1000 °C possesses the best rate capability among the three samples. For example, the pure phase FeMnO 3 sintered at 1000 °C delivers a specific capacity of 585 mA h g−1 after 290 cycles at the current of 1000 mA g−1; even at the high current density of 5 A g−1, the capacity still retained at 397 mA h g−1. Charge storage mechanism analysis revealed that the pure phase FeMnO 3 sintered at 1000 °C shows obvious pseudocapacitive behavior during the discharge/charge process, which partly account for its superior cycling performance and high-rate capability. • Coralline-like FeMnO 3 are synthesized by a facile co-precipitation method. • The coralline-like FeMnO 3 showed superior lithium storage performance. • The coralline-like FeMnO 3 showed significant pseudocapacitive behavior. • The FeMnO 3 exhibited a lithium diffusion coefficient of 2.42 × 10−15 cm2 s−1. [ABSTRACT FROM AUTHOR]

To solve the poor conductivity of the anode materials for lithium-ion batteries (LIBs) and enhance the lithium-ion transportation, silver-incorporated Fe 2 O 3 -C (Fe 2 O 3 -C-Ag) porous microcubes were fabricated through polydopamine reduction of AgNO 3 and subsequently high temperature carbonization process using the prussian blue as template. Interestingly, polydopamine not only served as reducing agent for Ag + but also as carbon source in this work, which avoid adding additional reduction agent and high temperature, resulting in a simple and mild reduction condition. When Fe 2 O 3 -C-Ag microcubes were performed as anode materials for lithium-ion batteries (LIBs), the hybrid materials behaved pretty electrochemical properties. The introduction of noble metal (Ag) and carbon to transition metal oxides was an innovative method to form anode materials for lithium-ion batteries (LIBs), which can effectively increase the conductivity of the electrode materials as well as inhibit the volume expansion during cycling. With 10% (wt%) Ag nanoparticles coating in the hybrid composites, the Fe 2 O 3 -C-Ag-10 microcubes exhibit good reversible capacities and pretty cyclic performance (858 mAh g −1 after 200 cycles at 100 mA g −1 ). This novel approach can provide a potential idea to design advanced anode materials for LIBs. [ABSTRACT FROM AUTHOR]

In this study, Fe 2 O 3 with oxygen vacancies (OVs) introduced by Ti doping is partially wrapped by reduced graphene oxide (rGO), and then grown directly on carbon cloth (CC) to obtain a self-supported electrode with hierarchical structures (Ti-Fe 2 O 3 @rGO/CC). Compared with Fe 2 O 3 nanosheets, Ti-doped Fe 2 O 3 nanosheets show better lithium storage performance because the existence of OVs can not only promote faster charge transfer kinetics but also help to maintain the integrity of electrode structure and improve the electrochemical activity. Especially, the rGO sheets are partially wrapped on Ti-Fe 2 O 3 , inhibiting the agglomeration of components and shortening the diffusion distance of Li+, to obtain better cycle stability. Moreover, it can also provide a buffer to alleviate the volume expansion, avoid the excessive growth of SEI film, and ensure that OVs can maximize their advantages under deep discharge conditions. The Ti-Fe 2 O 3 @rGO/CC electrode delivers a high capacity of 1193 mAh g−1 (3.245 mAh cm−2) at 200 mA g−1, showing great potential as an anode material for lithium-ion batteries. [Display omitted] • Fe 2 O 3 with oxygen vacancies was partially wrapped by rGO and loaded on carbon cloth as self-supported electrode. • The OVs promote fast charge transfer, maintain the electrode integrity and improve the electrochemical activity. • The rGO inhibits excessive growth of SEI film and ensures the OVs to maximize their advantage under deep discharge. • The electrode delivers high Coulomb efficiency and high reversible capacity. [ABSTRACT FROM AUTHOR]

Hollow carbon spheres (HCSs) materials have been investigated extensively for various applications in energy storage, catalysis, electrochemical conversion. At present, template method using liquid or gaseous carbon sources is the dominant synthetic route for HCSs. Herein, HCSs with high nitrogen doping levels are synthesized by employing graphitic carbon nitride (g-C 3 N 4) solid precursor as carbon and nitrogen sources with the presence of Zn templates. The successful synthesis of N-doped HCSs using solid g-C 3 N 4 precursor is confirmed by a series of characterization technologies. Serving as the anode materials in lithium ions batteries, promising lithium ions storage performances are obtained for the resultant N-doped HCSs. Brilliant specific capacities of 1506.6 mAh g−1 at 0.1 A g−1 and 519.2 mAh g−1 at 5 A g−1 are recorded after 360 cycles. The promising lithium ion storage performances of the N-doped HCSs are ascribed to the unique hollow structure with large surface area, suitable nitrogen doping level and large inner pore volume. The presented work provides a new route to synthesize HCSs or heteroatoms doped HCSs materials using solid carbon sources. • N-doped HCSs was synthesized using solid precursor with presence of Zn template. • Tunable N-doping levels from 21.47 to 33.32 at.% were realized for N-doped HCSs. • The Zn template was revealed to play the extra role of reduction denitrogenation. • N-doped HCSs delivers high specific capacity of 1506.6 mAh g−1 as LIBs anode. [ABSTRACT FROM AUTHOR]

The uneven dispersion of MnO easily leads to local volume change, resulting in the crushing and pulverizing of electrode. Herein, a spongy three-dimensional (3D) porous MnO/C composite was fabricated by pyrolysis of the double-network (DN) aerogel composed of agar (AG) and Mn-crosslinked sodium alginate (SA). The spongy MnO/C composite has homogeneous distribution and uniform size ultrafine MnO nanoparticles embedded into 3D porous carbon network and shows high BET surface area of 363 m2 g−1, which can not only improve the electrical conductivity, but effectively confine the expulsion of MnO and restrain the crushing and pulverizing of electrode. As anode for LIBs, the spongy MnO/C composite exhibits superior rate capability (574 mAh g−1, 2 A g−1) and excellent cycling stability. The capacity gradually increases during the cycling process, reaching 1270 mAh g−1 after 500 cycles at 2 A g−1. The rising capacity can be attributed to the following reasons: 1) more Mn2+ was oxidated to higher valence, 2) The enhanced amorphism of MnO improves Li+ diffusion kinetics, 3) the reversible form and decomposition of SEI. • A spongy three-dimensional porous MnO/C composite was fabricated. • MnO/C composite has homogeneous ultrafine MnO nanoparticles and high BET surface area. • MnO/C composite exhibits excellent rate capability and cycling stability. • MnO/C composite is a potential anode material. [ABSTRACT FROM AUTHOR]

As an alternative to Li-ion batteries, potassium-ion batteries have attracted increasing research interest due to the natural abundance of potassium and low cost. However, the larger ionic radius of the potassium easily causes a large volume expansion of the anode materials, eventually hindering the practical application of potassium-ion batteries. Here, we reported a heteroatomic doping mushroom biomass carbon (HDMC) as anode material for potassium-ion batteries. With high surface area and rich heteroatomic doping (N, S, and P), the as-prepared porous HDMC not only provides sufficient void space to relieve volume expansion of electrode but also offers highly efficient channels for fast transport of both electrons and potassium ions. The results demonstrated that the HDMC showed relatively high specific capacity (290 mAh g−1 at 500 mA g−1) and outstanding cycling stability after 2000 cycles. In-situ Raman spectroscopy and galvanostatic intermittent titration confirmed its surface-dominated potassium storage behavior with fast de-/potassiation kinetics, satisfactory reversibility, and fast ion/electron transport. This work guides an effective bionic strategy for the preparation of biomass carbon as high-performance anode materials. [Display omitted] • Mushroom-derived carbon is employed as anodes for the potassium-ion battery. • HDMC-500 has a high reversible capacity and outstanding rate capability. • H 3 PO 4 promotes the formation of activated and p-doped mushroom biomass. [ABSTRACT FROM AUTHOR]

Abstract: Sn–C nanocomposite is a promising anode material for high performance lithium-ion battery, but suffers from a complex synthesis procedure which hider its practical applicability. We report a simple and cheap synthesis method for Sn–C nanocomposites. By combining wet-chemical and carbonthermal reduction approaches, we are able to produce Sn–C nanocomposite in a simple one-pot synthesis during a successive heating procedure. Gel-derived nanocrystalline SnO2 is introduced into the precursor to act as a transition-phase for in situ growth of metallic tin nanocrystals. Consequently, this method allows for the fine control of the formation of the tin nanocrystals posterior to the carbonization of carbon sources through carbonthermal reduction of a nanosized SnO2. The resulting Sn–C nanocomposites deliver a remarkable lithium-ion insertion/extraction performance, such as high capacities of 588 and 367mAhg−1 at 20mAg−1 and 200mAg−1, respectively. [Copyright &y& Elsevier]