Nickel-rich layered oxides have drawn sustainable attentions for lithium ion batteries owing to their higher theoretical capacities and lower cost.However,nickel-rich layered oxides also have exposed several defects f...Nickel-rich layered oxides have drawn sustainable attentions for lithium ion batteries owing to their higher theoretical capacities and lower cost.However,nickel-rich layered oxides also have exposed several defects for commercial application,such as uncontrollable ordered layered structure,which leads to higher energy barrier for Li+diffusion.In addition,suffering from structural mutability,the bulk nickelrich cathode materials likely trigger overall volumetric variation and intergranular cracks,thus obstructing the lithium ion diffusion path and shortening the service life of the whole device.Herein,we report wellordered layered Li Ni0.8Co0.1Mn0.1O2 submicron spheroidal particles via an optimized co-precipitation and investigated as LIBs cathodes for high-performance lithium storage.The as-fabricated Li Ni0.8Co0.1Mn0.1O2 delivers high initial capacity of 228 mAh g–1,remarkable energy density of 866 Wh kg–1,rapid Li ion diffusion coefficient(10–9cm2s–1)and low voltage decay.The remarkable electrochemical performance should be ascribed to the well-ordered layered structure and uniform submicron spheroidal particles,which enhance the structural stability and ameliorate strain relaxation via reducing the parcel size and shortening Li-ion diffusion distance.This work anticipatorily provides an inspiration to better design particle morphology for structural stability and rate capability in electrochemistry energy storage devices.展开更多
Multi-band microwave absorption is becoming ubiquitous owing to the increasingly complex electromagnetic environment driven by the diversity of electronic devices.However,research on efficient electromagnetic absorber...Multi-band microwave absorption is becoming ubiquitous owing to the increasingly complex electromagnetic environment driven by the diversity of electronic devices.However,research on efficient electromagnetic absorbers applicable in both centimeter-wave and millimeter-wave bands to address the electromagnetic interference in 5G networks is highly challenging.In this study,Fe_(x)(Co_(y)Ni_(1-y))_(100-x)particles with two phases(face-centered cubic(FCC)and hexagonal close-packed(HCP))were synthesized and were found to exhibit excellent electromagnetic wave absorption.HCP phase with high magnetocrystalline anisotropy was introduced into FCC phase Fe_(x)(Co_(y)Ni_(1-y))_(100-x),resulting in natural resonances in multi-band frequency.Prominent microwave absorption properties in ultra-wide bandwidth ranging from 6.9 to 39.5 GHz were obtained.The maximum reflection loss(RL)of the Fe_(23)(Co_(0.5)Ni_(0.5))77 composite film reached-50 dB.Such a remarkable absorption performance is attributed to the synergetic effects of the multiple natural resonances generated by the coexistence of HCP and FCC phases in Fe23(Co0.5Ni0.5)77.Overall,this work is promising for the future design of high-performance microwave absorbing materials in a wide bandwidth.展开更多
Aiming at improving the capture performance of internal vortex electrostatic cyclone precipitator(ECP),a theoretical model with mechanics-electric-magnetic coupling was established,the collection efficiency of magneti...Aiming at improving the capture performance of internal vortex electrostatic cyclone precipitator(ECP),a theoretical model with mechanics-electric-magnetic coupling was established,the collection efficiency of magnetic confinement ECP under different working voltages was simulated,and the influence of magnetic flux intensity on the removal performance of submicron particles was explored.Results show that the number of particles escaped from the cyclone is greatly reduced after the introduction of magnetic field and electric field,indicating that charging effect and magnetic confinement are more conductive to trap submicron particles in the internal vortex ECP.The lower the working voltage is,the worse the charging lifting effect is,but the stronger the magnetic confinement characteristics are.Furthermore,the contributions of charging effect to collection efficiency and magnetic confinement characteristics are more obvious at a weaker magnetic flux density.The research results can provide a practical new idea for the innovative design of ECP.展开更多
基金This work was supported by the National Natural Science Foundation of China (Nos.21203107,51422204,and 51372132) and the National Basic Research Program of China (No.2013CB228506).
基金supported by the National Natural Science Foundation of China (21573083)1000 Young Talent (to Deli Wang)the Innovation Research Funds of HuaZhong University of Science and Technology (2017KFYXJJ164)。
文摘Nickel-rich layered oxides have drawn sustainable attentions for lithium ion batteries owing to their higher theoretical capacities and lower cost.However,nickel-rich layered oxides also have exposed several defects for commercial application,such as uncontrollable ordered layered structure,which leads to higher energy barrier for Li+diffusion.In addition,suffering from structural mutability,the bulk nickelrich cathode materials likely trigger overall volumetric variation and intergranular cracks,thus obstructing the lithium ion diffusion path and shortening the service life of the whole device.Herein,we report wellordered layered Li Ni0.8Co0.1Mn0.1O2 submicron spheroidal particles via an optimized co-precipitation and investigated as LIBs cathodes for high-performance lithium storage.The as-fabricated Li Ni0.8Co0.1Mn0.1O2 delivers high initial capacity of 228 mAh g–1,remarkable energy density of 866 Wh kg–1,rapid Li ion diffusion coefficient(10–9cm2s–1)and low voltage decay.The remarkable electrochemical performance should be ascribed to the well-ordered layered structure and uniform submicron spheroidal particles,which enhance the structural stability and ameliorate strain relaxation via reducing the parcel size and shortening Li-ion diffusion distance.This work anticipatorily provides an inspiration to better design particle morphology for structural stability and rate capability in electrochemistry energy storage devices.
基金This work was supported by Key Area Research Plan of Guangdong(No.2020B010176001)Shenzhen Science and Technology Program(Nos.KQTD20180411143514543 and JCYJ 20180504165831308)Shenzhen DRC project[2018]1433.
文摘Multi-band microwave absorption is becoming ubiquitous owing to the increasingly complex electromagnetic environment driven by the diversity of electronic devices.However,research on efficient electromagnetic absorbers applicable in both centimeter-wave and millimeter-wave bands to address the electromagnetic interference in 5G networks is highly challenging.In this study,Fe_(x)(Co_(y)Ni_(1-y))_(100-x)particles with two phases(face-centered cubic(FCC)and hexagonal close-packed(HCP))were synthesized and were found to exhibit excellent electromagnetic wave absorption.HCP phase with high magnetocrystalline anisotropy was introduced into FCC phase Fe_(x)(Co_(y)Ni_(1-y))_(100-x),resulting in natural resonances in multi-band frequency.Prominent microwave absorption properties in ultra-wide bandwidth ranging from 6.9 to 39.5 GHz were obtained.The maximum reflection loss(RL)of the Fe_(23)(Co_(0.5)Ni_(0.5))77 composite film reached-50 dB.Such a remarkable absorption performance is attributed to the synergetic effects of the multiple natural resonances generated by the coexistence of HCP and FCC phases in Fe23(Co0.5Ni0.5)77.Overall,this work is promising for the future design of high-performance microwave absorbing materials in a wide bandwidth.
基金sponsored by National Natural Science Foundation of China (Grant numbers 12172228,11572187)Natural Science Foundation of Shanghai (Grant number 22ZR1444400).
文摘Aiming at improving the capture performance of internal vortex electrostatic cyclone precipitator(ECP),a theoretical model with mechanics-electric-magnetic coupling was established,the collection efficiency of magnetic confinement ECP under different working voltages was simulated,and the influence of magnetic flux intensity on the removal performance of submicron particles was explored.Results show that the number of particles escaped from the cyclone is greatly reduced after the introduction of magnetic field and electric field,indicating that charging effect and magnetic confinement are more conductive to trap submicron particles in the internal vortex ECP.The lower the working voltage is,the worse the charging lifting effect is,but the stronger the magnetic confinement characteristics are.Furthermore,the contributions of charging effect to collection efficiency and magnetic confinement characteristics are more obvious at a weaker magnetic flux density.The research results can provide a practical new idea for the innovative design of ECP.
