Three-Dimensional (3D) Ordered Macroporous Bimetallic (Mn,Fe) Selenide/Carbon Composite with Heterojunction Interface for High-Performance Sodium Ion Batteries.

Transition-metal selenides have captured significant research attention as anode materials for sodium ion batteries (SIBs) due to their high theoretical specific capacities and excellent electronic conductivity. However, volumetric expansion and inferior cycle life still hinder their practical application. Herein, a three-dimensional (3D) ordered macroporous bimetallic (Mn,Fe) selenide modified by a carbon layer (denoted as 3DOM-MnFeSe@C) composite containing a heterojunction interface is fabricated through selenizing a 3D ordered macroporous Mn-based Prussian Blue analogue single crystal.

Preparation of Aerogel-like Silica Foam with the Hollow-Sphere-Based 3D Network Skeleton by the Cast-in Situ Method and Ambient Pressure Drying.

Silica aerogels have incomparable advantages among thermal insulation materials because of their ultralow density and thermal conductivity, but cumbersome production processes, high cost, and low mechanical stability limit their practical application. In this study, a novel aqueous process to prepare lightweight aerogel-like silica foams (ASFoams) through the cast-in situ method and ambient pressure drying was proposed with multiblock polyurethane surfactant as the vesicle template. ASFoams possess a unique loose stacking morphology of the silica hollow sphere with a 3D network structure as the skeleton, which endues ASFoams with a low density of 0.

Unveiling the Advances of Nanostructure Design for Alloy-Type Potassium-Ion Battery Anodes via In Situ TEM.

Nanostructure design and in situ transmission electron microscopy (TEM) are combined to demonstrate Sb-based nanofibers composed of bunched yolk-shell building units as a significantly improved anode for potassium-ion batteries (PIBs). Particularly, a metal-organic frameworks (MOFs)-engaged electrospinning strategy coupled to a confined ion-exchange followed by a subsequent thermal reduction is proposed to fabricate yolk-shell Sb@C nanoboxes embedded in carbon nanofibers (Sb@CNFs). In situ TEM analysis reveals that the inner Sb nanoparticles undergo a significant volume expansion/contraction during the alloying/dealloying processes, while the void space can effectively relieve the overall volume change, and the plastic carbon shell maintains the structural integrity of electrode material.