Lithium (Li) metal is the ultimate anode choice for next generation high energy density batteries. However, the high nucleation energy barrier and nonuniform electric field distribution, as well as huge volume expansion, lead to the uncontrollable growth of Li dendrites and poor utilization of Li metal, which hinders its practical application. Herein, titanium dioxide/cuprous oxide (TiO₂/Cu₂O) heterostructure is constructed on the rimous skeleton of Cu mesh, and the heterostructure decorated rimous Cu mesh (H-CM) can act as both current collector and host for dendrite-free Li metal anode. The TiO₂/Cu₂O heterostructure realizes selective Li nucleation by nano TiO₂ and then induces fast and uniform Li conduction with the aid of heterostructure interface and nano Cu₂O contributing to dendrite-free Li deposition. While the internal and external space of rimous skeletons in H-CM is used to accommodate the deposited Li and buffer its volume change. Therefore, the cycling reversibility of the derived Li metal anode in H-CM is improved to a high Coulombic efficiency of 98.8% for more than 350 cycles at a current density of 1 mA·cm⁻², and 1,000 h (equals to 500 cycles) stable repeated Li plating/stripping can be operated in a symmetric cell. Furthermore, full cells with limited Li anode and high loading LiFePO₄ cathode present excellent cycling and rate performances.

Porous Si can be synthesized from diverse silica (SiO₂) via magnesiothermic reduction technology and widely employed as potential anode material in lithium ion batteries. However, concerns regarding the influence of residual silicon oxide (SiO_x) component on resulted Si anode after reduction are still lacked. In this work, we intentionally fabricate a cauliflower-like silicon/silicon oxide (CF-Si/SiO_x) particles from highly porous SiO₂ spheres through insufficient magnesiothermic reduction, where residual SiO_x component and internal space play an important role in preventing the structural deformation of secondary bulk and restraining the expansion of Si phase. Moreover, the hierarchically structured CF-Si/SiO_x exhibits uniformly-dispersed channels, which can improve ion transport and accommodate large volume expansion, simultaneously. As a result, the CF-Si/SiO_x-700 anode shows excellent electrochemical performance with a specific capacity of ~1,400 mA·h·g^-1 and a capacity retention of 98% after 100 cycles at the current of 0.2 A·g^-1.

Porous Fe₃O₄/carbon microspheres (PFCMs) were successfully fabricated via a facile electrospray method and subsequent heat treatment, using ferrous acetylacetonate, carbon nanotubes (CNTs), Ketjen black (KB), polyvinylpyrrolidone (PVP), and polystyrene (PS) as raw materials. The porous carbon sphere framework decorated with well-dispersed CNTs and KB exhibits excellent electronic conductivity and acts as a good host to confine the Fe₃O₄ nanoparticles. The abundant mesopores in the carbon matrix derived from polymer pyrolysis can effectively accommodate the volume changes of Fe₃O₄ during the charge/discharge process, facilitate electrolyte penetration, and promote fast ion diffusion. Moreover, a thin amorphous carbon layer on the Fe₃O₄ nanoparticle formed during polymer carbonization can further alleviate the mechanical stress associated with volume changes, and preventing aggregation and exfoliation of Fe₃O₄ nanoparticles during cycling. Therefore, as anode materials for lithium-ion batteries, the PFCMs exhibited excellent cycling stability with high specific capacities, and outstanding rate performances. After 130 cycles at a small current density of 0.1 A·g^–1, the reversible capacity of the PFCM electrode is maintained at almost 1, 317 mAh·g^–1. High capacities of 746 and 525 mAh·g^–1 were still achieved after 300 cycles at the larger currents of 1 and 5 A·g^–1, respectively. The optimized structure design and facile fabrication process provide a promising way for the utilization of energy storage materials, which have high capacities but whose performance is hindered by large volume changes and poor electrical conductivity in lithium or sodium ion batteries.