Self-Assembled Nanoparticle Supertubes as Robust Platform for Revealing Long-Term, Multiscale Lithiation Evolution

Abstract

Herein, free-standing supertubes, composed of a single layer of close-packed carbon-coated nanoparticles, are fabricated by a confined-epitaxial-assembly strategy. Benefiting from the tubular geometry, monolayer superlattice structure, and uniform and conformal carbon coating, such free-standing supertubes promise high electrochemical performance while simultaneously serving as a robust platform for reliably elucidating the structure-performance relationship of lithium-ion batteries (LIBs). As a model, Fe 3 O 4 supertubes, when used as LIB anodes, can deliver a capacity of $800 mAh g À1 after 500 cycles at 5 A g À1 , outperforming most Fe 3 O 4-based materials reported previously. More importantly, the structural evolution of Fe 3 O 4 supertubes is revealed at meso-/nano-/atomic scales simultaneously upon lithiation and delithiation, which correlates well with the battery's capacity reactivation, stabilization, and degradation behaviors during the course of 500 cycles.

Mesoporous Nanoarchitectures for Electrochemical Energy Conversion and Storage

“…Bowl-like mesoporous particles [29] Bouquet-posy-like mesoporous particles [43] Mesoporous nanosheets [44] Ordered mesoporous supertubes [45] Head-tail mesoporous silica nanoparticles [46] Easy production of complex mesoporous nanostructures…”

“…Figure and Table 1 summarize various methods to synthesize mesoporous nanostructures. [ 12,27–58 ] Based on the formation mechanism of mesoporous nanomaterials, these methods can be categorized into five groups: 1) the soft‐template method, 2) the hard‐template method, 3) the unconventional‐template method, 4) the hybrid‐template method, and 5) the template‐free method.…”

“…Such free‐standing supertubes are realized by a tubular template‐assisted epitaxial assembly of uniform nanocrystals followed by in situ ligand carbonization and template removal. [ 45 ] The low‐dimensional morphology of the mesostructured nanomaterials is tuned by controlling the assembly modes of mesostructured subunits (e.g., micelles and nanocrystals) at nanoscale, opening up some possibility for accurate tailoring complex mesoarchitectures in the future.…”

All‐Graphitic Multilaminate Mesoporous Membranes by Interlayer‐Confined Molecular Assembly

“…[ 23,25 ] Further studies demonstrate that the morphology of mesoporous graphene can be tuned in a wide range (e.g., spheres and films), simply by controlling the self‐assembly conditions of colloidal nanocrystals. [ 26–28 ] From these results, we anticipate that multilayer mesostructured graphene is attainable if the self‐assembly of nanocrystal superlattices at the interlayer space of densely stacked graphene can be achieved. However, a mixture of nanocrystals and graphene can easily undergo phase separation during self‐assembly, owing to the drastically different geometry and surface chemistry between the two mixed‐dimensional components.…”

Metal-Organic Powder Thermochemical Solid-Vapor Architectonics toward Gradient Hybrid Monolith with Combined Structure-Function Features

“…[10][11][12][13] To meet these requirements, a gradient metal/carbon hybrid electrode is proposed by integrating heteroatomic doping (to modify the electronic structure), low-dimensional graphitic structure (i.e., carbon nanotubes to improve contact with the reaction species and electron transport), and metal-encapsulated graphitic layer (to decrease the adsorption free energy of hydrogen) on one side, shaping like ceramics in macroscale on the other side (to provide mechanical strength and the shape), and connecting the two sides by incorporating microscale graphitic structure (to provide fast charge transport and mechanical strength) in the middle region. [14][15][16][17][18][19][20][21][22] To manufacture this type of gradient electrode, one possible way is to grow metal-encapsulated Ndoped carbon nanotube arrays on closely packed carbon ceramics. However, this approach is difficult to accomplish in a one-pot fashion because the deposition of…”