Lithium-sulfur(Li-S) battery is one of the best candidates for the next-generation energy storage system due to its high theoretical capacity(1675 mA h-1),low cost and environment friendliness.However,lithium(Li) dend...Lithium-sulfur(Li-S) battery is one of the best candidates for the next-generation energy storage system due to its high theoretical capacity(1675 mA h-1),low cost and environment friendliness.However,lithium(Li) dendrites formation and polysulfide shuttle effect are two major challenges that limit the commercialization of Li-S batteries.Here we design a facile bifunctional interlayer of gelatin-based fibers(GFs),aiming to protect the Li anode surface from the dendrites growth and also hinder the polysulfide shuttle effect.We reveal that the 3D structural network of GFs layer with abundant polar sites helps to homogenize Li-ion flux,leading to uniform Li-ion deposition.Meanwhile,the polar moieties also immobilize the lithium polysulfides and protect the Li metal from the side-reaction.As a result,the anodeprotected batteries have shown significantly enhanced performance.A high coulombic efficiency of 96% after 160 cycles has been achieved in the Li-Cu half cells.The Li-Li symmetric cells exhibit a prolonged lifespan for 800 h with voltage hysteresis(10 mV).With the as-prepared GFs layer,the Li-S battery shows approximately 14% higher capacity retention than the pristine battery at 0.5 C after 100 cycles.Our work presents that this gelatin-based bi-functional interlayer provides a viable strategy for the manufacturing of advanced Li-S batteries.展开更多
Lithium-sulfur(Li-S)batteries have been recognized as one of the most promising candidates for nextgeneration portable electronic devices,owing to their extremely high energy density and low cost.However,the dissoluti...Lithium-sulfur(Li-S)batteries have been recognized as one of the most promising candidates for nextgeneration portable electronic devices,owing to their extremely high energy density and low cost.However,the dissolution of lithium polysulfides(LiPSs)and consequent"shuttle effect"seriously hinder the practical deployment of Li-S batteries.Herein,multi-metal oxide nanorods named attapulgite are proposed as multifunctional ionic sieve to immobilize LiPSs and further promote the regulation of LiPSs.Attapulgite,consisting of Al,Mg,Fe,Si and O ions,possesses more polar sites to immobilize LiPSs in comparison with single metal oxides.In addition,the catalytic nature(Fe ions)of attapulgite avails the LiPSs conversion reaction,which is further confirmed by the linear sweep voltammetry and electrochemical impedance spectroscopy.Benefited from the synergistic effect of multi-metal oxide and conductive carbon,the Li-S battery with the modified separator delivers remarkable discharge capacities of 1059.4 mAh g-1 and 792.5 mAh g-1 for the first and 200th cycle at 0.5 C,respectively.The work presents an effective way to improve the electrochemical performance of Li-S batteries by employing attapulgite nanorods assisted separator surface engineering.展开更多
As a sulfur-containing cathode material,sulfide polyacrylonitrile(SPAN)is expected to be used for longlife lithium-sulfur battery because there is no shuttle effect occurred in its charge process.However,its specific ...As a sulfur-containing cathode material,sulfide polyacrylonitrile(SPAN)is expected to be used for longlife lithium-sulfur battery because there is no shuttle effect occurred in its charge process.However,its specific capacity and discharge potential need to be further improved to satisfy the urgent demands for high-performance batteries.In this paper,Te0.045S0.955PAN composite was synthesized by co-heating TexS1-x and PAN,and the superior electrochemical performance to that of SPAN was obtained because of doping Te with high conductivity.The as-prepared Te0.045S0.955PAN composite possessed the specific capacity of 675 mAh g^-1 after 100 cycles at the current density of 0.1 A g^-1 with high capacity retention of96.6%compared to the second cycle.Especially,during cycling,Te0.045S0.955PAN showed average discharge voltages of 1.88-1.91 V,which were higher than 1.85-1.88 V for SPAN at the same current density.Thus doping Te provides a new strategy for increasing the energy density of SPAN.展开更多
To address the corrosion and dendrite issues of lithium metal anodes, a protective layer was ex-situ constructed by P4S10 modification. It was determined by X-ray photoelectron spectroscopy and Raman spectra that the ...To address the corrosion and dendrite issues of lithium metal anodes, a protective layer was ex-situ constructed by P4S10 modification. It was determined by X-ray photoelectron spectroscopy and Raman spectra that the main constituents of the protective layer were P4S10, Li3PS4 and other LixPySztype derivatives. The protective layer was proved to be effective to stabilize the interphase of lithium metal. With the modified Li anodes, symmetric cells could deliver stable Li plating/stripping for 16000 h;Li–S batteries exhibited a specific capacity of 520 m A h g-1 after 200 cycles at 1000 m A g-1 with average Coulombic efficiency of 97.9%. Therefore, introducing LixPySzbased layer to protect Li anode provides a new strategy for the improvement of Li metal batteries.展开更多
Various nanostructured architectures have been demonstrated to be effective to address the issues of high capacity Si anodes. However, the scale-up of these nano-Si materials is still a critical obstacle for commercia...Various nanostructured architectures have been demonstrated to be effective to address the issues of high capacity Si anodes. However, the scale-up of these nano-Si materials is still a critical obstacle for commercialization. Herein, we use industrial ferrosilicon as low-cost Si source and introduce a facile and scalable method to fabricate a micrometer-sized ferrosilicon/C composite anode, in which ferrosilicon microparticles are wrapped with multi-layered carbon nanosheets. The multi-layered carbon nanosheets could effectively buffer the volume variation of Si as well as create an abundant and reliable conductivity framework, ensuring fast transport of electrons. As a result, the micrometer-sized ferrosilicon/C anode achieves a stable cycling with 805.9 m Ah g-1 over 200 cycles at 500 mA g-1 and a good rate capability of455.6 mAh g-1 at 10 A g-1. Therefore, our approach based on ferrosilicon provides a new opportunity in fabricating cost-effective, pollution-free, and large-scale Si electrode materials for high energy lithium-ion batteries.展开更多
NIST(National Institute of Standards and Technology) statistical test recognized as the most authoritative is widely used in verifying the randomness of binary sequences. The Non-overlapping Template Matching Test as ...NIST(National Institute of Standards and Technology) statistical test recognized as the most authoritative is widely used in verifying the randomness of binary sequences. The Non-overlapping Template Matching Test as the 7 th test of the NIST Test Suit is remarkably time consuming and the slow performance is one of the major hurdles in the testing process. In this paper, we present an efficient bit-parallel matching algorithm and segmented scan-based strategy for execution on Graphics Processing Unit(GPU) using NVIDIA Compute Unified Device Architecture(CUDA). Experimental results show the significant performance improvement of the parallelized Non-overlapping Template Matching Test, the running speed is 483 times faster than the original NIST implementation without attenuating the test result accuracy.展开更多
基金supported by the National Natural Science Foundation of China (No. 51861165101)。
文摘Lithium-sulfur(Li-S) battery is one of the best candidates for the next-generation energy storage system due to its high theoretical capacity(1675 mA h-1),low cost and environment friendliness.However,lithium(Li) dendrites formation and polysulfide shuttle effect are two major challenges that limit the commercialization of Li-S batteries.Here we design a facile bifunctional interlayer of gelatin-based fibers(GFs),aiming to protect the Li anode surface from the dendrites growth and also hinder the polysulfide shuttle effect.We reveal that the 3D structural network of GFs layer with abundant polar sites helps to homogenize Li-ion flux,leading to uniform Li-ion deposition.Meanwhile,the polar moieties also immobilize the lithium polysulfides and protect the Li metal from the side-reaction.As a result,the anodeprotected batteries have shown significantly enhanced performance.A high coulombic efficiency of 96% after 160 cycles has been achieved in the Li-Cu half cells.The Li-Li symmetric cells exhibit a prolonged lifespan for 800 h with voltage hysteresis(10 mV).With the as-prepared GFs layer,the Li-S battery shows approximately 14% higher capacity retention than the pristine battery at 0.5 C after 100 cycles.Our work presents that this gelatin-based bi-functional interlayer provides a viable strategy for the manufacturing of advanced Li-S batteries.
基金supported by the National Natural Science Foundation of China(Nos.51861165101,51822706,51777200)Beijing Natural Science Foundation(No.JQ19012)DNL Cooperation Fund,CAS(DNL201912)。
文摘Lithium-sulfur(Li-S)batteries have been recognized as one of the most promising candidates for nextgeneration portable electronic devices,owing to their extremely high energy density and low cost.However,the dissolution of lithium polysulfides(LiPSs)and consequent"shuttle effect"seriously hinder the practical deployment of Li-S batteries.Herein,multi-metal oxide nanorods named attapulgite are proposed as multifunctional ionic sieve to immobilize LiPSs and further promote the regulation of LiPSs.Attapulgite,consisting of Al,Mg,Fe,Si and O ions,possesses more polar sites to immobilize LiPSs in comparison with single metal oxides.In addition,the catalytic nature(Fe ions)of attapulgite avails the LiPSs conversion reaction,which is further confirmed by the linear sweep voltammetry and electrochemical impedance spectroscopy.Benefited from the synergistic effect of multi-metal oxide and conductive carbon,the Li-S battery with the modified separator delivers remarkable discharge capacities of 1059.4 mAh g-1 and 792.5 mAh g-1 for the first and 200th cycle at 0.5 C,respectively.The work presents an effective way to improve the electrochemical performance of Li-S batteries by employing attapulgite nanorods assisted separator surface engineering.
基金financially supported by the National Key Research and Development program of China(no.2016YFB0100200)Beijing Municipal Science and Technology Project(no.Z181100004518001)
文摘As a sulfur-containing cathode material,sulfide polyacrylonitrile(SPAN)is expected to be used for longlife lithium-sulfur battery because there is no shuttle effect occurred in its charge process.However,its specific capacity and discharge potential need to be further improved to satisfy the urgent demands for high-performance batteries.In this paper,Te0.045S0.955PAN composite was synthesized by co-heating TexS1-x and PAN,and the superior electrochemical performance to that of SPAN was obtained because of doping Te with high conductivity.The as-prepared Te0.045S0.955PAN composite possessed the specific capacity of 675 mAh g^-1 after 100 cycles at the current density of 0.1 A g^-1 with high capacity retention of96.6%compared to the second cycle.Especially,during cycling,Te0.045S0.955PAN showed average discharge voltages of 1.88-1.91 V,which were higher than 1.85-1.88 V for SPAN at the same current density.Thus doping Te provides a new strategy for increasing the energy density of SPAN.
基金financially supported by the National Key Research and Development Program of China(no.2016YFB0100200)Beijing Municipal Science and Technology Project(no.Z181100004518001)。
文摘To address the corrosion and dendrite issues of lithium metal anodes, a protective layer was ex-situ constructed by P4S10 modification. It was determined by X-ray photoelectron spectroscopy and Raman spectra that the main constituents of the protective layer were P4S10, Li3PS4 and other LixPySztype derivatives. The protective layer was proved to be effective to stabilize the interphase of lithium metal. With the modified Li anodes, symmetric cells could deliver stable Li plating/stripping for 16000 h;Li–S batteries exhibited a specific capacity of 520 m A h g-1 after 200 cycles at 1000 m A g-1 with average Coulombic efficiency of 97.9%. Therefore, introducing LixPySzbased layer to protect Li anode provides a new strategy for the improvement of Li metal batteries.
基金the National Natural Science Foundation of China(No:21703285)。
文摘Various nanostructured architectures have been demonstrated to be effective to address the issues of high capacity Si anodes. However, the scale-up of these nano-Si materials is still a critical obstacle for commercialization. Herein, we use industrial ferrosilicon as low-cost Si source and introduce a facile and scalable method to fabricate a micrometer-sized ferrosilicon/C composite anode, in which ferrosilicon microparticles are wrapped with multi-layered carbon nanosheets. The multi-layered carbon nanosheets could effectively buffer the volume variation of Si as well as create an abundant and reliable conductivity framework, ensuring fast transport of electrons. As a result, the micrometer-sized ferrosilicon/C anode achieves a stable cycling with 805.9 m Ah g-1 over 200 cycles at 500 mA g-1 and a good rate capability of455.6 mAh g-1 at 10 A g-1. Therefore, our approach based on ferrosilicon provides a new opportunity in fabricating cost-effective, pollution-free, and large-scale Si electrode materials for high energy lithium-ion batteries.
基金supported in part by Shanxi Scholarship Council of China(Grant No.2017-key-2)the Natural Science Foundation of Shanxi Province(Grant No.201801D121145)+1 种基金the Natural Science Foundation of China(NSFC)(Grant No.61731014,61705157,61927811)the Program for Guangdong Introducing Innovative and Entrepreneurial Teams。
文摘NIST(National Institute of Standards and Technology) statistical test recognized as the most authoritative is widely used in verifying the randomness of binary sequences. The Non-overlapping Template Matching Test as the 7 th test of the NIST Test Suit is remarkably time consuming and the slow performance is one of the major hurdles in the testing process. In this paper, we present an efficient bit-parallel matching algorithm and segmented scan-based strategy for execution on Graphics Processing Unit(GPU) using NVIDIA Compute Unified Device Architecture(CUDA). Experimental results show the significant performance improvement of the parallelized Non-overlapping Template Matching Test, the running speed is 483 times faster than the original NIST implementation without attenuating the test result accuracy.
