Template-Free Fabrication of Mesoporous Hollow ZnMn2O4 Sub-microspheres with Enhanced Lithium Storage Capability towards High-Performance Li-Ion Batteries

In this work, we rationally designed an efficient template-free synthetic strategy to fabricate hierarchical mesoporous hollow ZnMn2O4 sub-microspheres (HZSMs) constructed entirely from nanoparticle (NP) building blocks of size approximate to 15 nm. The well-known inside-out Ostwald ripening process was tentatively proposed to shed light on the formation mechanism of the mesoporous hollow nano-/microarchitecture. In favor of the intrinsic structural advantages, these resulting HZSMs exhibited superior electrochemical lithium-storage performance with high specific capacity, excellent cyclability, and good rate capability when evaluated as an anode material for advanced Li-ion batteries (LIBs). The excellent electrochemical performance should be reasonably ascribed to the porous and hollow structure of the unique HZSMs with nanoscale subunits, which reduced the diffusion length for Li+ ions, improved the kinetic process and enhanced the structural integrity with sufficient void space for tolerating the volume variation during the Li+ insertion/extraction. These results further revealed that the as-prepared mesoporous HZSMs would be a promising anode for high-performance LIBs.