Magnetically accelerated thermal energy storage within Fe_(3)O_(4)-anchored MXene-based phase change materials

Inherent weak photon-capturing ability is a long-standing bottleneck for pristine phase change materials(PCMs)in photothermal conversion application.To conquer this difficulty,herein,magnetic Fe_(3)O_(4) nanoparticles were in situ anchored between the layers and the surface of two-dimensional MXene for the infiltration of myristic acid(MA)by an in situ chemical anchoring strategy.Benefiting from the synergistic localized surface plasmon resonance effect of MXene and Fe_(3)O_(4) nanoparticles,our designed MXene@Fe_(3)O_(4)-MA composite PCMs harvested an ultrahigh photothermal conversion efficiency of 97.7%.During the photothermal conversion process,MXene can capture photons and convert solar energy into heat energy efficiently,and the in situ anchored Fe_(3)O_(4) nanoparticles further enhanced the photothermal conversion efficiency.Moreover,the introduction of Fe_(3)O_(4) nanoparticles improved the thermal energy storage density(144.17 J/g)of MXene-MA composite PCMs since Fe_(3)O_(4) nanoparticles provided more heterogeneous nucleation sites for MA.Simultaneously,MXene@Fe_(3)O_(4)-MA composite PCMs were endowed with excellent paramagnetism,and realized efficient magnetic-thermal conversion.Additionally,MXene@Fe_(3)O_(4)-MA composite PCMs exhibited excellent energy conversion stability,thermal stability,and reliability after undergoing multiple thermal cycles.Therefore,high-performance MXene@Fe_(3)O_(4)-based energy conversion composite PCMs are promising candidates to accelerate efficient utilization of the practical solar energy and magnetic energy.

Emerging multifunctional iron-based nanomaterials as polysulfides adsorbent and sulfur species catalyst for lithium-sulfur batteries——A mini-review

Lithium-sulfur(Li-S)battery has been considered as one of the most promising next generation energy storage technologies for its overwhelming merits of high theoretical specific capacity(1673 m Ah/g),high energy density(2500 Wh/kg),low cost,and environmentally friendliness of sulfur.However,critical drawbacks,including inherent low conductivity of sulfur and Li2S,large volume changes of sulfur cathodes,undesirable shuttling and sluggish redox kinetics of polysulfides,seriously deteriorate the energy density,cycle life and rate capability of Li-S battery,and thus limit its practical applications.Herein,we reviewed the recent developments addressing these problems through iron-based nanomaterials for effective synergistic immobilization as well as conversion reaction kinetics acceleration for polysulfides.The mechanist configurations between different iron-based nanomaterials and polysulfides for entrapment and conversion acceleration were summarized at first.Then we concluded the recent progresses on utilizing various iron-based nanomaterials in Li-S battery as sulfur hosts,separators and cathode interlayers.Finally,we discussed the challenges and perspectives for designing high sulfur loading cathode architectures along with outstanding chemisorption capability and catalytic activity.