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A hybridized composite material of α-Fe 2 O 3 nanoparticles/human hair-derived carbon (HHC) is prepared using a facile two-step method combined carbonization of human hair with homogeneous precipitation under microwave irradiation. Results show that the uniform α-Fe 2 O 3 nanoparticles were highly dispersed on the surface of porous human hair-derived carbon. As an anode material for Li-ion batteries, it retains a reversible capacity of 1000 mAh g −1 after 200 cycles at 0.2 C. A discharge capacity higher than 750 mAh g −1 and 550 mAh g −1 is also recorded at 1 C and 2 C after 200 cycles, respectively. Such superior electrochemical performance of α-Fe 2 O 3 /HHC composite could be attributed to the favorable structure of HHC, which can improve the electron and lithium ion transport ability as anode. This study provides a cost-effective, highly efficient means to fabricate materials which combine keratin wastes-derived carbon with active nanoparticles for the development of high-performance lithium-ion battery materials. [ABSTRACT FROM AUTHOR]

Abstract: A novel network LiFePO4/C composite was prepared by mixing precursor solution with carbon aerogel (CA) via a simple solution impregnation method, characterized by XRD, SEM, EDS and electrochemical analysis. The results revealed that the LiFePO4 nanowire forming on the ektexine of CA intertwined with LiFePO4/CA particles and formed a special web structure. The initial discharge capacity was improved to be 139.3 mAh g−1 at 10 C and the capacity retention is near 100% after 50 cycles. The web structure could improve electron transport and electrochemical activity effectively. [Copyright &y& Elsevier]

Abstract: La3+ and F− co-doped Li4Ti5O12 (LTO) anode materials are synthesized successfully via a solid state reaction. The structure and morphology are characterized by XRD, SEM and EDS. The results indicate that La3+ and F− ions were uniformly dispersed in Li4Ti5O12 lattice without changing the structure and morphology of Li4Ti5O12. Li3.95La0.05Ti5O11.7F0.3 (La005-F03) exhibits an outstanding electrochemical performance among all the samples in a potential range from 0.5 to 2.5 V, and delivers a discharge capacity of 103 mAh g−1 at 10C rate, whereas the LTO only gives 62.5 mAh g−1. The sample La005-F03 retains a discharge capacity of 170.1 mAh g−1 after 100 cycles at 1C rate. The improved electrochemical performance could be attributed to the appropriate co-doping with La3+ and F−, which can increase the amount of Ti3+/Ti4+ mixing as charge compensation, leading to the decrease of the charge transfer resistance and improvement of the electronic conductivity and lithium ion diffusion coefficient. [Copyright &y& Elsevier]

• Biphasic Fe 7 S 8 @MnS heterostructure embedded in sulfur-doped carbon matrix was synthesized. • The composites exhibit enhanced lithium storage performance with high rate capability and long cycling stability. • These results can be attributed to the multiphasic components with heterostructures and porous conductive carbon frameworks. Transition metal chalcogenides have been regarded as promising anode candidates for lithium-ion batteries, featured by their high capacity and abundant material choice. However, their practical implementation was hindered by the poor reaction kinetics and rapid capacity fading due to their low electronic conductivity and severe volume variation upon the (de-)lithiation processes. Here, we have successfully fabricated the biphasic Fe 7 S 8 @MnS heterostructure embedded in sulfur-doped carbon matrix by direct sulfidation of Fe/Mn bimetal-organic frameworks. The biphasic heterostructure and the porous carbon frameworks can create abundant phase boundaries and multiple conductive channels for change transfer, thus improving the electronic conductivity and contact area with electrolyte, leading to facilitated charge transfer capability. As a result, the Fe 7 S 8 @MnS/C composites exhibit superior lithium storage performance with a specific capacity of 917 mA h g−1 at 0.1 A g−1 and maintain at 581 mA h g−1 after 500 cycles at 1 A g−1. This work provides an efficient strategy for constructing multiphase nanomaterials towards high performance anodes for Li-ion batteries. [ABSTRACT FROM AUTHOR]

Metal-organic framework (MOF) derivatives are attracting increasing interests for next-generation lithium-ion battery anode materials. Here, a novel approach has been applied to synthesize binary Mn–Zn oxides nanohybrids embedded in porous carbon matrix by pyrolysis of dual-metal-organic frameworks. The as-fabricated MnO/ZnO@C nanohybrids exhibit superior lithium storage capabilities, reaching a reversible capacity of 1396 mAh g−1 at 0.2 A g−1 with an initial coulombic efficiency of higher than 75%. When cycled at 2 A g−1, the electrode maintained at 636 mAh g−1 after 1000 cycles, indicating the outstanding high-rate capability and cycling stability. The improved electrochemical performance can be attributed to the interconnected porous structure of carbon frameworks and uniform heterostructure nanohybrids, which efficiently improve the charge transfer and buffer the volume expansion during repeated lithiation process. These findings demonstrate an efficient strategy of using dual-MOF-derived bi-metal oxide nanostructures as high performance anodes for lithium-ion batteries. Image 1 • Dual-metal-organic frameworks was proposed for metal oxides nanohybrids synthesis. • ZnO@MnO nanohybrids embedded in porous carbon matrix were synthesized. • The fabricated nanohybrids exhibit superior lithium storage capabilities. • The mesoporous structure and heterostructure benefit the performance. [ABSTRACT FROM AUTHOR]

• Biomass-derived carbon is used for conversion-alloying type anodes. • ZnMn 2 O 4 nanoparticles in porous carbon are successfully synthesized. • The composites deliver superior lithium storage performance with high capacity and good cyclability. • The unique structure with ZnMn 2 O 4 nanoparticle and porous carbon integration accounts for the superior performance. Conversion-alloying type anode materials are conceived as very promising candidates to replace graphite for high-energy lithium-ion batteries. Here, we demonstrated a facial approach using biomass-derived carbon to improve the ZnMn 2 O 4 materials as anodes. A composite of ZnMn 2 O 4 nanoparticles/pine needle-derived carbon is synthesized with a high reversible capacity of 1000 mA h g−1 at 0.2 C and superior rate capability of 727 mA h g−1 at 2.0 C without capacity loss for 500 cycles. Pseudocapacitive contribution and highly improved conversion reaction mechanisms are responsible for the capacity improvement. Moreover, the conductive biomass-derived porous carbon can facilitate the charge transfer and buffer the volume expansion upon conversion-alloying reactions of the ZnMn 2 O 4 materials. This work provides a feasible way to fabricate low-cost and high performance materials for lithium-ion batteries towards higher sustainability. [ABSTRACT FROM AUTHOR]