Core‐Shell Nanoparticles with a Redox Polymer Core and a Silica Porous Shell as High‐Performance Cathode Material for Lithium‐Ion Batteries

Abstract

A facile and novel method for the fabrication of core‐shell nanoparticles (PTMA@SiO2) based on a poly(2,2,6,6‐tetramethylpiperidinyloxy‐4‐yl methacrylate) (PTMA) core and a porous SiO2 shell is reported. The core‐shell nanoparticles are further self‐assembled with negatively charged multi‐walled carbon nanotubes (MWCNTs), which results in the formation of a free‐standing cathode electrode. The porous SiO2 shell not only effectively improves the stability of the linear PTMA redox polymer with low molar mass in organic electrolytes but also leads to the uniform dispersion of PTMA active units in the MWCNTs conductive network. The PTMA@SiO2@MWCNT composite electrode exhibits a specific capacity as high as 73.8 mAh g at 1 C and only 0.11% capacity loss per cycle at a rate of 2 C.

Synthesis and Characterization of Polyethylenimine–Silica Nanocomposite Microparticles

“…To date, a number of promising methods for polymer–silica composite production have been developed toward applications such as absorbents, cargo vehicles, and sensors. For example, the common sol–gel reaction of organosilanes, facilitated by either acid, base, or coupling agents in the presence of ready-made polymeric cores, has been used to develop various polymer–SiO 2 composites as drug vehicles, ,, catalysts, latent heat storage materials, cathodes, analytical reference materials, , abrasives, and the base material for scintillators . Also, polymer–SiO 2 hybrids hold great potential as absorbents for future environmental remediation technologies.…”

Chameleon Multienvironment Nanoreactors

“…This results in the formation of a PTMPM- co -PTMA copolymer, in which TMPM and TMA units are likely randomly distributed. Thanks to the assistance of CTAB as a surfactant and template, a layer of porous silica was coated around the PTMPM- co -PTMA core, in agreement with our previously reported method . Finally, core–shell nanospheres composed of a typical random PTMPM- co -PTMA copolymer core that encapsulates Au nanoparticles and a hydrophilic porous SiO 2 shell were obtained and denoted as PTMPM- co -PTMA­@Au­@porous SiO 2 (PPAPS).…”

“…Thanks to the assistance of CTAB as a surfactant and template, a layer of porous silica was coated around the PTMPM-co-PTMA core, in agreement with our previously reported method. 20 Finally, core−shell nanospheres composed of a typical random PTMPM-co-PTMA copolymer core that encapsulates Au nanoparticles and a hydrophilic porous SiO 2 shell were obtained and denoted as PTMPM-co-PTMA@Au@porous SiO 2 (PPAPS). The loading quantity of Au nanoparticles inside PPAPS was confirmed by ICP-OES as detailed in the Experimental Section.…”