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MOF-derived XMn 2 O 4 (X = Zn, Co, Cu, Ni) nanomaterials achieve superior electrochemical performance for lithium storage. [Display omitted] • Two methods are proposed for the synthesis of XMn 2 O 4 (X = Zn, Co, Cu, Ni). • MOF-derived anodes exhibit excellent electrochemical capabilities compared with the ones obtained by simple coprecipitation. • Lithium storage capacity and rate performance of XMn 2 O 4 is best when X = Zn. • DFT calculations are performed to demonstrate that ZnMn 2 O 4 as an anode material is conducive to the diffusion of Li+. Bimetallic spinel transition metal oxides play a major part in actualizing eco-friendly electrochemical energy storage systems (ESSs). However, structural precariousness and low electrochemical capacitance restrict their actual implementation in lithium-ion batteries (LIBs). To address these demerits, the sacrificial template approach has been considered as a prospective way to strengthen electrochemical stability and rate performance. Herein, metal-organic frameworks (MOFs) derived XMn 2 O 4 -BDC (H 2 BDC = 1,4-dicarboxybenzene, X = Zn, Co, Cu, Ni) are prepared by a hydrothermal approach in order to discover the effects of various metal cations on the electrochemical performance. Among them, ZnMn 2 O 4 -BDC displays best electrochemical properties (1321.5 mAh g−1 at the current density of 0.1 A g−1 after 300 cycles) and high efficiency with accelerated Li+ diffusivity. Density functional theory (DFT) calculations confirm the ZnMn 2 O 4 possesses the weakest adsorption energy on Li+ with a minimized value of −0.92 eV. In comparison with other XMn 2 O 4 through traditional fabrication method, MOF-derived XMn 2 O 4 -BDC possesses a higher number of Li+ transport channels and better electric conductivity. This tactic provides a feasible and effective method for preparing bimetallic transition metal oxides and enhances energy storage applications. [ABSTRACT FROM AUTHOR]

[Display omitted] • A double-layer coating strategy is used to enhance the performance of SiO x anode. • The dual-shell structure consists of an Sn inner layer and N-doped outer layer. • The inner Sn can improve electronic conductivity and charge transfer kinetics. • The outer N-doped carbon shell can further maintain the structural integrity. • The dual-shell SiO x /C@Sn@NC anode exhibits excellent lithium storage ability. SiO x -based anode materials (0 < x < 2) have been regarded as an appealing candidate for anode material of commercial Lithium-ion batteries accounting for their ultrahigh theoretical capacity and low cost. However, its large-scale applications have been hampered by the serious volume expansion during repeated cycles, low intrinsic conductivity and unsatisfactory initial Coulombic efficiencies. Herein, to address these inherent deficiencies, a hierarchical SiO x -based anode with double-layer coatings of Sn inner layer and N-doped carbon outer shell is elaborately designed by a facile two-step hydrolysis process and polymer coating technology. Benefiting from the "synergistic effect" between Sn and SiO x at different working potentials and a well-designed double-layer coating structure, the resultant SiO x /C@Sn@NC anode displays excellent electrochemical properties, including an enhanced initial Coulomb efficiency (73.3%) efficiency, higher reversible capacity (991 mAh g−1) and superior long lifespan. Moreover, comprehensive characterization based on the reaction kinetics and structural stability proved that such enhanced ICE and cycling stability of anode material stem from its unique double-layer coating structure and multiple active components, which can significantly improve the diffusion of ion and charge transport, stabilize solid-electrolyte interphase (SEI) layer and absorb the expansion stress of electrode. Therefore, this study provides an efficient and feasible strategy to overcome the limitations of high-capacity SiO x -based anode materials via hybridization design with various active components and a double-layer coating strategy. [ABSTRACT FROM AUTHOR]

Attracted due to their potentially high theoretical capacities, storage redox activities, and diverse shape, cobalt phosphides (Co 2 P, CoP etc.) are thought to be the promising anodes for lithium-ion batteries (LIBs). Nevertheless, there still remain challenging bottlenecks of their low intrinsic conductivity and severe volume expansion when subjected to repeated electrochemical cycles, which unavoidably bring about structural collapse, active particle aggregation and rapid capacity degradation, and thereby poor long-term lifespan. Herein, we present a distinctively facile route and adopt metal-organic frameworks (MOFs) as the self-sacrificing hosts to construct carbon-encapsulated CoP/Co 2 P@N C composites which are composed of monodispersed electroactive Co x P (CoP/Co 2 P) nanoparticles encapsulated in carbon nanotubes (CNTs) based on N-doped carbon substrates. Remarkably, one exemplary CoP/Co 2 P@N C-600 electrode among them, when serves as anode for LIBs, exhibits high reversible capacity (977.9 mAh g−1, 100 cycles at 0.1 A g−1) and superior rate capability (639.7 mAh g−1 at 4 A g−1). Furthermore, an assembled LFP//CoP/Co 2 P@N C-600 full cell displays remarkable cycling performance. The more advantageous synergistic interaction of distinctive carbon-encapsulated architectures, robust N-doped carbon frameworks and electroactive components provides the fundamental foundation for superior lithium storage capabilities, where the synergistic interaction contributes towards enhancing electronic conductivity, offering extra electrochemical active sites, shortening the Li+/e− transport channels and alleviating volumetric variation. This contribution emphasizes the value of rationally designing MOF-derived carbon-encapsulated metal phosphide-based anodes for advanced LIBs. [ABSTRACT FROM AUTHOR]

• Graphite was regenerated by acid leaching and graphene-like carbon coating. • The structure defects of graphite are well repaired. • The graphene-like carbon layer improves electrochemical performance of graphite. • The recycled graphite can meet the standard of commercial material. The recycling of waste electrode materials from spent lithium-ion batteries (LIBs) is attracting widespread attention from the perspective of the reutilization of resources and environment protection. Nevertheless, the low added value, complex separation steps and the structure defects induced in the long-term charge/discharge process reduce people's interest for secondary utilization of waste graphite anode. More importantly, if waste graphite anode is not prudently treated, it will cause black pollution. Herein, we report a facile and efficient graphene-like coating strategy for the regeneration of waste graphite. Using low-cost Humic Acid as the coated carbon source and waste graphite as the core, graphene-like-coated graphite anode material was prepared by sulfuric acid leaching and in situ carbonization of Humic Acid. Humic Acid containing aromatic rings can be in-situ converted to a graphene-like coating layer to repair the surface defects of graphite during thermal treatment, which can effectively restore the Li+ transport channels, improve the rate performance and cycle stability of the reconstructed graphite anode. When it is reused as anode material of LIBs, the reconstructed graphite anode shows a high initial Coulombic efficiency of 86.2 %, high capacity of 352.76 mAh/g and good retention capacity rate of 86.7 % after 400 cycles at 0.5C. Therefore, the graphene-like coating strategy provides a significant exploration for the recycling and regeneration of waste graphite anode materials, and it is conducive to the realization of the carbon peaking and carbon neutrality goals. [ABSTRACT FROM AUTHOR]

• Construct carbon protective shell to alleviate huge volume changes of Si. • Robust carbon framework can effectively maintains the structure integrity. • Carbon buffer layer can offer rich e-/ion channels to improve reaction kinetics. • The SCM electrode exhibited excellent electrochemical performance. Si-based anodes have revealed the potential as the next generation of lithium ion battery anode material, whereas the poor conductivity and huge volume changes during (de)lithiation process of silicon still limit their practical application. Herein, the Si/nitrogen doped carbon layer/carbon framework microspheres (SCM) are designed by nano-Si via electro-spray technology as anodes for lithium ion batteries. It has been found that the SCM consists of individual carbon-coated nano-Si primary particles linked by PAN framework, in which the carbon buffer layer can further absorb the stress of volume changes during charge/discharge process, and the carbon framework carbon framework not only provides fast diffusion path of electron, but also effectively reduces the consumption of electrolyte. Therefore, the initial columbic efficiency (ICE) of SCM anode can reach as high as 72%, and the SCM anode also shows a high specific capacity of 1192 mAh g−1 at 0.2 A g−1 and keeps a reversible capacity of 746 mAh g−1 after 200 cycles, demonstrating the as-designed SCM possesses an high ICE and a good electrochemical performance. This strategy provides a significant inspiration for fabricating high-performance Si/C anode materials of lithium-ion battery. [ABSTRACT FROM AUTHOR]