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Abstract Nanostructure CuFe 2 O 4 /CuO composites are synthesized via a precipitation method with different surfactants mediated Prussian blue analogues (PBAs) as precursors and following calcination in air. Comparatively, P-CuFe 2 O 4 /CuO (synthesized with PVP) and graphene oxide (GO) are hydrothermal processed to obtain P-CuFe 2 O 4 /CuO/reduced-GO. The PBAs precursors present as small spherical particles with PVP (P-CuPB), irregular polygon blocks with SDBS (S-CuPB) and CTAB (C-CuPB). Porous CuFe 2 O 4 /CuO with different size are obtained after calcining the PBAs and employed as anode of lithium ion batteries. The P-CuFe 2 O 4 /CuO exhibits an excellent capacity of 630.5 mAh g−1 with coulombic efficiency (CE) above 97%, which are better than the other two samples, and P-CuFe 2 O 4 /CuO/R-GO shows further improved reversible and stable capacity of 720 mAh g−1 with CE above 99% cycled at 500 mA g−1 even after 300 times. The results imply that surfactants can influence the particle structure and lithium storage performance. Besides, R-GO can effectively increase lithium ions insertion/de-insertion kinetics by supplying the matrix and buffer cushion for metal oxide volume changing during cycling. Graphical abstract Image 1 Highlights • Nanostructured CuFe 2 O 4 /CuO mediated by PBAs with different surfactants are obtained. • A simple soft-template synthesis mechanism was proposed. • CuFe 2 O 4 /CuO anode synthesized by PVP exhibited better lithium storage performance. • CuFe 2 O 4 /CuO/R-GO anode shown 720 mAh g−1 at 0.5 A g−1 even after 300 cycles. [ABSTRACT FROM AUTHOR]

Cu-MOF with a hollow morphology was successfully synthesized by a novel and simple coordination transformation reaction of [Cu(NH 3 ) 4 ] 2+ with benzenetricarboxylic acid (H 3 BTC) under ultrasound irradiation for the first time. Then, novel hollow porous CuO/C nanorods were prepared by calcining this Cu-MOF at low temperature (250 °C) in air. The morphology and electrochemical properties of the samples were markedly affected by the calcination temperature. As anode materials for lithium-ion batteries, the hollow porous nanorod structure and the presence of carbon greatly enhanced the electrochemical performance of the CuO/C nanocomposite. The reversible specific capacity of CuO/C was 505 mA h g −1 at a current density of 100 mA g −1 after 200 cycles, which is much higher than that of the CuO samples calcined at 300 °C and 350 °C (250.1 mA h g −1 and 192.3 mA h g −1 , respectively) in air. The CuO/C nanocomposite also exhibited a more favorable rate capability than CuO. The superior electrochemical performance makes this nanocomposite a promising anode material for LIBs. [ABSTRACT FROM AUTHOR]

Inverse spinel SnFe 2 O 4 as an anode material for lithium-ion batteries (LIBs) suffers from poor cycling stability due to its lower conductivity and excess volume change during charge/discharge process. In order to overcome the obstacles, a series of SnFe 2 O 4 @reduced graphene oxide (rGO) composites with different amount of Sn(Fe)–C bonds between SnFe 2 O 4 and rGO interface are synthesized through a simple one-pot solvothermal method and subsequent sintering at different temperatures. The composite with higher Sn(Fe)–C bonds content exhibits higher charge/discharge capacities of 1010/1020 mAh g−1 at 0.5 A g−1 for 300 cycles, and a better rate capability of 620 mAh g−1 at 2.0 A g−1. The synergistic effect of larger content of Sn(Fe)–C bonds and the formed flower-like networks between the pulverized SnFe 2 O 4 and the rGO interface during charge/discharge is favor to improve the kinetics of SnFe 2 O 4 , because the networks are acted as the transport highway for electronics and lithium-ions. Moreover, the higher content and strong action of Sn(Fe)–C bonds can prevent the SnFe 2 O 4 nanoparticles suffer from excessively volume change and pulverize during cycling. Designing chemically bonded metal oxides with graphene composite could provide a simple way to improve the cycle stability and rate capability of the LIBs. Image 1 • Various amount of Sn(Fe)–C bonds between SnFe 2 O 4 and graphene interface are obtained. • The composite with higher content of Sn(Fe)–C bonds exhibits higher capacities. • Flower like networks formed on SFG interface act as transport highway for Li+. • The anode shows high stable capacity of 1020 mAh g−1 at 0.5 A g−1 for 300 cycles. [ABSTRACT FROM AUTHOR]

Developing environment friendly and low cost methods of fabricating advanced anode materials for lithium ion batteries (LIBs) is very important. Using nori as the precursor, we designed and synthesized the composite of nitrogen-phosphorus-codoped carbon matrixes and cobaltic oxide nanoparticles (N, P-codoped C/Co 3 O 4 ) via hydrolysis of CoCl 2 and calcination method. It is interested that the nori not only provided the dopant of N and P elements but also formed the sponge-like porous carbon matrices which exhibited a large specific surface area as 246.4 m 2 g −1 . Both the dopants and the 3D porous carbon matrix are significantly helpful in improving the electrochemical performance of the product. Used as the anode material of LIB, N, P-codoped C/Co 3 O 4 offered a high reversible specific capacity of 927 mA h g −1 (the theoretical capacity of Co 3 O 4 is 890 mA h g −1 ) after 100 cycles at the current density of 100 mA g −1 and a good rate capability of 454 mA h g −1 at the current density of 1 A g −1 . Thus it is a promising alternative advanced anode material for LIB. In addition, the whole process is green, simple, economical and scalable and the method may be applied to synthesize other N, P-codoped carbon based composites. [ABSTRACT FROM AUTHOR]

FeMnO 3 /Mn 2 O 3 hybrids were prepared by calcinating the Mn 3 [Fe(CN) 6 ] 2 · n H 2 O Prussian Blue Analogues (PBAs) precursor, which involving a room-temperature precipitation of Mn 2+ and K 3 Fe(CN) 6 with or without citric acid as additives. The as-prepared FeMnO 3 inherits the morphology of PBAs and shows a porous structure due to releasing of CO 2 and NO 2 gases in the calcination process in air. FeMnO 3 nanocubes fulling of larger pores mixed with a new morphology of Mn 2 O 3 nanotubes are formed due to the assistance of citric acid (Sample Fe x Mn 2- x O 3 -C). While the single morphology of FeMnO 3 and Mn 2 O 3 nanocubes are obtained without citric acid (Sample Fe x Mn 2- x O 3 ). The Fe x Mn 2-x O 3 -C anode exhibits super Li + storage performance than that of Fe x Mn 2-x O 3 anode, such as higher initial discharge/charge capacities of 1580 and 850 mAh g −1 , and maintain 995 mAh g −1 until 170 cycles at a current density of 200 mA g −1 . The enhanced electrochemical performance is attributed to the inter-connected porous structure and large amount of mesopores of FeMnO 3 nanocubes and Mn 2 O 3 nanotubes, which effectively improved structure stability, reduced the diffusion length of lithium ions and electrons, increased the diffusion coefficient of Li + ion throughout the electrode, and buffered volume expansion during the Li + insertion/extraction processes. These results indicate that the porous FeMnO 3 nanocubes/Mn 2 O 3 nanotubes hybrids can be a promising anode material for high-performance LIBs. [ABSTRACT FROM AUTHOR]

SnO 2 -based anode of lithium-ion batteries (LIB) suffers from excessive volume expansion and low conductivity, resulting in very poor capacity stability and rate capability. To solve the problems, three kinds of SnO 2 /Sn@carbon heterostructures were synthesized by a salt template following calcination using tartaric acid, p-phthalic acid and ethylenediamine tetraacetic acid with different carboxyl groups as carbon sources, respectively. The acidity, carbon atoms number and position affect the ratio of SnO 2 /Sn, the morphology and content of derived carbon, the advantage crystal plane and the surface defects of SnO 2. The carbon atoms located at carboxyl are transformed to CO and formed pores, and the carbon atoms at alkane chain are polycondensed and transformed to amorphous carbon during annealing process. The SnO 2 /Sn@C derived from tartaric acid (SnO 2 /Sn@TA) has the largest ratio of SnO 2 /Sn, which fixed on graphene-like porous carbon, exposed the most surface defects and more high energy crystal plane. The specific structure ensures structural stability and ultrahigh capacity, lower Li+ diffusion barrier energy and super rate capability. It exhibits the charge/discharge capacity of 1059.7/1064.4 mAh g−1 at 2 A g−1 after 1500 cycles and super rate performance of 399.3/404.5 mAh g−1 at 6 A g−1, which are superior to most reference data. [Display omitted] • Different heterostructures of SnO 2 /Sn@graphene-like porous carbon was synthesized. • C atoms at -COOH transform to CO to create pores, at alkane chain into amorphous C. • SnO 2 /Sn@C heterostructure decreases Li+ diffusion distance and barrier energy. • SnO 2 /Sn@C exhibits ultra-high capacity of 1064 mAh g−1 at 2 A g−1 for 1500 cycles. [ABSTRACT FROM AUTHOR]

SnS is regarded as an ideal material for electrodes in next-generation lithium-ion batteries (LIBs) due to its high specific capacity and low cost. However, the low conductivity and larger volume expansion during charge/discharge hinder its practical application. In this paper, a novel core-shell tremella fuciformis shaped SnS@Sulfur doped carbon composite (SnS@C) was constructed by reduction of as-prepared nanoflower SnS 2 and carbonazation of carboxymethyl cellulose using a crystallized NaCl as template under N 2 atmosphere. The sulfur doping carbon shell with more defects can increase not only the electrical conductivity but also enhance the mechanical strength of the SnS@C due to the larger space provided by interconnected tremella fuciformis shaped structure, as well as can provide more active sites for lithium-ions intercalation/de-intercalation by surface pseudocapacitive behavior. It remains stable capacity of 1078 mAh g−1 cycled at 0.2 A g−1 after 200 cycles, and 801 mAh g−1 even at 1.0 A g−1 for 500 cycles, and 403 mAh g−1 even at 5 A g−1 of rate performance. The simple synthesis scheme not only creates more reactive sites, but also forms a stable 3D interconnected carbon skeleton structure, which is suitable for other energy storage and conversion materials too. [Display omitted] • A core-shell tremella fuciformis shaped SnS@S doped carbon composite was obtained. • S doped carbon shell was obtained by a simple reduction of SnS 2 and carbonization method. • S doping of carbon enhance the defects and favor for Li+ storage as surface pseudocapacitive. • The carbon shell of SnS@C increases the conductivity and stablize the SnS structure. • 3D interconnected petals provide large space and more active sites for Li+ storage. [ABSTRACT FROM AUTHOR]

SnS is regarded as an ideal material for electrodes in next-generation lithium-ion batteries (LIBs) due to its high specific capacity and low cost. However, the low conductivity and larger volume expansion during charge/discharge hinder its practical application. In this paper, a novel core-shell tremella fuciformis shaped SnS@Sulfur doped carbon composite (SnS@C) was constructed by reduction of as-prepared nanoflower SnS 2 and carbonazation of carboxymethyl cellulose using a crystallized NaCl as template under N 2 atmosphere. The sulfur doping carbon shell with more defects can increase not only the electrical conductivity but also enhance the mechanical strength of the SnS@C due to the larger space provided by interconnected tremella fuciformis shaped structure, as well as can provide more active sites for lithium-ions intercalation/de-intercalation by surface pseudocapacitive behavior. It remains stable capacity of 1078 mAh g−1 cycled at 0.2 A g−1 after 200 cycles, and 801 mAh g−1 even at 1.0 A g−1 for 500 cycles, and 403 mAh g−1 even at 5 A g−1 of rate performance. The simple synthesis scheme not only creates more reactive sites, but also forms a stable 3D interconnected carbon skeleton structure, which is suitable for other energy storage and conversion materials too. [Display omitted] • A core-shell tremella fuciformis shaped SnS@S doped carbon composite was obtained. • S doped carbon shell was obtained by a simple reduction of SnS 2 and carbonization method. • S doping of carbon enhance the defects and favor for Li+ storage as surface pseudocapacitive. • The carbon shell of SnS@C increases the conductivity and stablize the SnS structure. • 3D interconnected petals provide large space and more active sites for Li+ storage. [ABSTRACT FROM AUTHOR]