Stereoselectively Assembled Metal-Organic Framework (MOF) Host for Catalytic Synthesis of Carbon Hybrids for Alkaline-Metal-Ion Batteries.

Cost-effective metal-based nanostructured hybrids have been widely dedicated to potential energy storage and conversion applications. Herein, we develop a facile methodology for the synthesis of precise carbon-confined hybrid nanostructures by stereoselective assembly accompanied by catalytic pyrolysis. Polyacrylonitrile fiber films favors not only metal-polymer coordination, but also oriented assembly to ensure the well-defined nanostructure of the carbon hybrids. During chemical vapor deposition (CVD), cobalt-nanoparticle-catalyzed growth of carbon-nanotube branches driven by organic molecules (e.g. melamine) delivers hierarchical carbon hybrids. The resulting carbon hybrids exhibit outstanding electrochemical performance for metal-ion batteries, for example, a high specific capacity of 680 mAh g-1 after 320 cycles (Li-storage) and 220 mAh g-1 after 500 cycles (Na-storage) without decay.

Achieving Electronic Engineering of Vanadium Oxide-Based 3D Lithiophilic Sandwiched-Aerogel Framework for Ultrastable Lithium Metal Batteries.

Lithium (Li) metal is one of the most promising anode materials for the next-generation batteries, which owns superior specific capacity and energy density. Unfortunately, lithium dendrites that is formed during the charging/discharging process tends to induce capacity degradation and thus short lifespan. In this study, the vanadium oxide (V2O5) and nitrogen-doped vanadium oxide (N-V2O3, N-VO0.9)-modified three-dimensional (3D) reduced graphene oxide ((N)-VOx@rGO) with tunable electronic properties are demonstrated to enable the dendrite-free Li deposition. The soft lithiophilic rGO as the scaffold can provide sufficient void space for Li storage. Meanwhile, the rigid (N)-VOx uniformly anchored on rGO can perfectly maintain the 3D structure, which is crucial for Li to enter the inner space of the 3D framework. Consequently, the (N)-VOx@rGO electrodes achieve dendrite-free electrodeposition under the multifarious deposition capacity and current densities. Compared with the bare lithium electrodes, the asymmetrical cells of (N)-VOx@rGO anode can cycle stably up to 400 h at 2 mA cm-2 current density, together with a low nucleation overpotential of ∼20 mV.

Ultrafast Microwave Polarizing Electrons to Form Vertically Aligned Metal Hybrids as Lithiophilic Buffer for Lithium-Metal Batteries.

Lithium-metal batteries (LMBs) have attracted great attention because of their high theoretical capacity and low electrochemical potential. However, uncontrollable Li dendrite growth and significant volume expansion result in safety issues that largely limit their practical applications. Herein, we explore a microwave-assisted strategy for the rapid synthesis of vertically aligned metal hybrids on Cu foil (VAMH@CF). Such an elaborate architecture of VAMH provides a lithiophilic buffer layer after prelithiation, offering vast nucleation sites/seeds for Li deposition (Li@VAMH@CF) and lower nucleation overpotential. Consequently, Li@VAMH@CF exhibits an outstanding cyclability with a long lifespan (up to 5500 cycles) and a low voltage hysteresis (28 mV) in a symmetrical cell at 3 mA cm-2. LiFePO4||Li@VAMH@CF full cells deliver a reversible capacity of about 140 mAh g-1 for 200 cycles, further demonstrating opportunities of the microwave-involved strategy for optimizing Li-metal anodes.