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Transition metal oxides (TMOs) are promising materials for next‐generation lithium‐ion batteries while the lithium storage and cycling stability of TMOs are still limited. Herein, a novel Co3O4/MnO2/C composite using metal‐organic frameworks (MOFs) as sacrificial templates is reported. MnO2 and C shells are layer by layer coated on the MOF‐derived Co3O4/C samples via hydrothermal technique and heat treatment. When employed as anode materials for LIBs, the hierarchically heterostructured Co3O4/MnO2/C composites incorporate the merits of Co3O4, MnO2, and C, showing high Li storage performances at a current density of 0.2 A g−1 with an initial capacity of ∼1245.7 mAh g−1 and a reversible capacity of ∼854.9 mAh g−1 after 100 cycles, remarkable cycling stability, and excellent rate capability (almost 98 % recovery as the current density returns to the initial 0.2 A g−1, and especially, the specific capacity remains ∼587.6 mAh g−1 at a high current density of 2.0 A g−1). [ABSTRACT FROM AUTHOR]

To solve the problem associated with the huge volume change and low conductivity of Mn3O4, a novel C/Mn3O4 microsphere with Mn3O4 layer and void space sandwiched by nitrogen‐doped carbon (NC) is designed and fabricated. In this composite, the NC is obtained from the metal–organic frameworks (MOFs) and polydopamine (PDA). The preparation process is facile and effective without additional templates or redox solvents introduced. When used as anodes for lithium‐ion batteries (LIBs), the C/Mn3O4 composite incorporates the metrics of N‐doping, yolk‐shell structure, double carbon layer, mesoporous Mn3O4, showing an outstanding lithium storage of ≈1015.9 mAh g−1 at 0.2 A g−1 in the 250th cycle, high cycling stability (without clear capacity decay after 400 cycles), and excellent rate capability (capacity can fully recover as the current density returns back to the initial value of 0.2 A g−1). The yolk‐shell structure derived from MOFs can be expanded to fabricate other materials with improved performance. [ABSTRACT FROM AUTHOR]

• CNTs and N-doped carbon decoration can enhance electronic conductivity of Si-based anode. • CoSi 2 can improve the structural stability of Si-based anode. • The introduced Co can catalyze the graphitization of carbon shell. • The designed Si-based anode delivers enhanced electrochemical properties. [Display omitted] Silicon is evaluated as a competitive lithium-ion batteries anode material by virtue of its ultrahigh specific capacity and relatively low discharge potential. However, the large volume change during lithiation/delithiation processes, and the low intrinsic electric conductivity have seriously impeded its widespread practical application. Herein, silicon nanoparticles (SiNPs) coated with CNTs-intertwined N-doped porous carbon (NPC) are prepared via a facile solution-phase method, followed by thermal annealing treatment. In this hierarchical structure, the bimetallic ZIF-derived porous carbon can shorten the migration channels of Li+ and electrons. Moreover, the formed Co nanoparticles can not only catalyze the graphitization of carbon, but also propel in-situ growth of CNTs to constitute a 3D interconnected conductive network, thereby improving the electrochemical performance. Benefiting from the unique structure, the as-prepared Si@CoSi 2 /Co-NPC@CNTs electrode exhibits superior electrochemical performance of 1191 mAh g−1 at 0.5 A g−1 after 200 cycles. Meanwhile, the electrode also shows excellent rate capability of 930 mAh g−1 even at a high current density of 6 A g−1. This work provides a new strategy to design exceptionally high electrical conductivity and structure stability of Si-based anode materials. [ABSTRACT FROM AUTHOR]

Si has been regarded as one of the most promising anodes for next-generation lithium ion batteries for its high theoretical capacity (3579 mA h g−1) and low operating potential of 0.4 V vs Li/Li+. However, the huge volume change during (de)lithiation and low electronic conductivity impede its further commercial applications. In this work, Zn/Si porous multi-layer films with controllable layer number (from 1 to 6 layers) are constructed firstly, and then a ZnO thin layer is sputtered on the top surface of the Zn/Si films to fabricate the Zn/Si/ZnO porous multi-layer films. When used as binder-free anodes, the designed 4 layers Zn/Si/ZnO thin film anode delivers the highest specific capacity, best cycling and rate performance than other multi-layer film anodes and the bulk Zn/Si/ZnO film anode with the same overall thickness. The excellent electrochemical properties of the prepared 4 layers Zn/Si/ZnO porous composite film anode can be attributed to its porous and multilayer structure, which can moderate the volume change, decrease the internal stress and benefit to the penetration of electrolyte. Moreover, the 3D electron and Li+ ion conductive channels resulted from the formed Li–Zn alloy during cycling can help to increase the electrochemical reaction kinetics. • Porous multilayer structure helps moderate the volume change of Si film anode. • Ion and electron conductive alloy framework increase the reaction kinetics. • The introduced Li 2 O layer helps to stabilize the electrode interface. [ABSTRACT FROM AUTHOR]