Chloro-propylene sulfite （CIPS） was employed as electrolyte additive of Li/S batteries for the first time. Linear potential sweep test showed that the CIPS keeps high electrochemical stability even under the voltage...Chloro-propylene sulfite （CIPS） was employed as electrolyte additive of Li/S batteries for the first time. Linear potential sweep test showed that the CIPS keeps high electrochemical stability even under the voltage of 5.0V. Being used as electrolyte additive in Li/S batteries, CIPS displayed an excellent property for self-discharge prohibition. With CIPS additive the Li/S cells initial discharge capacity was 856.2 mAh·g^-1 and 830.8 mAh·g^-1 at the current density of 15 mA.g and 30 mA·g^-1 , after 30 cycles the discharge capacities were contained at as high as 753.8 mAh.g and 715.6 mAh·g^-1. By means of infrared spectra, TG/DTA experiment and element conten analysis the speculated reason of CIPS＇s novel function as additive was proposed.展开更多
Sluggish kinetics of lithium/sulfur(Li/S)conversion chemistry and the ion channels formation in the cathode is still a bottleneck for developing future Li/S batteries with high-rate,long-cycling and high-energy.Here,a...Sluggish kinetics of lithium/sulfur(Li/S)conversion chemistry and the ion channels formation in the cathode is still a bottleneck for developing future Li/S batteries with high-rate,long-cycling and high-energy.Here,a rational cathode structure design of an oxygen(O)and nitrogen(N)tailoring carbon fiber aerogel(OCNF)as a host material integrated with platinum(Pt)electrocatalysis interface is employed to regulate Li/S conversion chemistry and ion channel.The Pt nanoparticles were uniformly sprayed onto the S surface to construct the electrocatalysis interface(Pt/S/OCNF)for generating ion channels to promote the effective penetration of electrolyte into the cathode.This Pt/S/OCNF gives the cathode a high sulfur utilization of 77.5%,an excellent rate capacity of 813.2 m Ah/g(2 C),and an outstanding long-cycling performance with a capacitance retention of 82.6%and a decay of 0.086%per cycle after 200 cycles at 0.5 C.Density functional theory(DFT)calculations reveal that the Pt electrocatalysis interface makes the cathode a high density of state(DOS)at Fermi level to facilitate the electrical conductivity,charge transfer kinetics and electrocatalysis to accelerate the lithium polysulfides(LiPSs)electrochemical conversion.Furthermore,the unique chemisorption structure and adsorption ability of Li2Sn(n=1,2,4,6,8)and S8on OCNF are attributed to the bridging effects of interfacial Pt and the bonding of N-Li.The Pt electrocatalysis interface combined with the unique 3D hierarchical porous structure and abundant functional active sites at OCNF guarantee strong adsorption confinement,fast Li/S electrocatalytic conversion and unblocked ion channels for electrolyte permeation in cathode.展开更多
文摘Chloro-propylene sulfite （CIPS） was employed as electrolyte additive of Li/S batteries for the first time. Linear potential sweep test showed that the CIPS keeps high electrochemical stability even under the voltage of 5.0V. Being used as electrolyte additive in Li/S batteries, CIPS displayed an excellent property for self-discharge prohibition. With CIPS additive the Li/S cells initial discharge capacity was 856.2 mAh·g^-1 and 830.8 mAh·g^-1 at the current density of 15 mA.g and 30 mA·g^-1 , after 30 cycles the discharge capacities were contained at as high as 753.8 mAh.g and 715.6 mAh·g^-1. By means of infrared spectra, TG/DTA experiment and element conten analysis the speculated reason of CIPS＇s novel function as additive was proposed.
基金funding support from National Key R&D Program of China(No.2016YFB0100100)The National Natural Science Foundation of China(Nos.21961024,21961025,21433013,U1832218)+5 种基金Inner Mongolia Natural Science Foundation(No.2018JQ05)Supported by Incentive Funding from Nano Innovation Institute(NII)of Inner Mongolia University for Nationalities(IMUN)Inner Mongolia Autonomous Region Funding Project for Science&Technology Achievement Transformation(No.CGZH2018156)Inner Mongolia Autonomous Region Incentive Funding Guided Project for Science&Technology Innovation(2016)Inner Mongolia Autonomous Region Science&Technology Planning Project for Applied Technology Research and Development(No.2019GG261)Tongliao Funding Project for Application Technology Research&Development(2017)。
文摘Sluggish kinetics of lithium/sulfur(Li/S)conversion chemistry and the ion channels formation in the cathode is still a bottleneck for developing future Li/S batteries with high-rate,long-cycling and high-energy.Here,a rational cathode structure design of an oxygen(O)and nitrogen(N)tailoring carbon fiber aerogel(OCNF)as a host material integrated with platinum(Pt)electrocatalysis interface is employed to regulate Li/S conversion chemistry and ion channel.The Pt nanoparticles were uniformly sprayed onto the S surface to construct the electrocatalysis interface(Pt/S/OCNF)for generating ion channels to promote the effective penetration of electrolyte into the cathode.This Pt/S/OCNF gives the cathode a high sulfur utilization of 77.5%,an excellent rate capacity of 813.2 m Ah/g(2 C),and an outstanding long-cycling performance with a capacitance retention of 82.6%and a decay of 0.086%per cycle after 200 cycles at 0.5 C.Density functional theory(DFT)calculations reveal that the Pt electrocatalysis interface makes the cathode a high density of state(DOS)at Fermi level to facilitate the electrical conductivity,charge transfer kinetics and electrocatalysis to accelerate the lithium polysulfides(LiPSs)electrochemical conversion.Furthermore,the unique chemisorption structure and adsorption ability of Li2Sn(n=1,2,4,6,8)and S8on OCNF are attributed to the bridging effects of interfacial Pt and the bonding of N-Li.The Pt electrocatalysis interface combined with the unique 3D hierarchical porous structure and abundant functional active sites at OCNF guarantee strong adsorption confinement,fast Li/S electrocatalytic conversion and unblocked ion channels for electrolyte permeation in cathode.
