Flexible lithium-sulfur(Li-S)batteries are considered one of the most promising candidates for highenergy-density storage devices in wearable electronics.However,the safety problem severely restricts the practical app...Flexible lithium-sulfur(Li-S)batteries are considered one of the most promising candidates for highenergy-density storage devices in wearable electronics.However,the safety problem severely restricts the practical application of Li-S batteries because of the possible occurrence of thermal runaway caused by battery short circuits and combustible components,particularly under bending conditions.The development of advanced separators that can suppress lithium dendrite growth and are incombustible is the key to improving the safety of flexible Li-S batteries.In this work,a nonflammable multifunctional Janus separator with self-extinguishing capability,high thermal stability,high thermal conductivity,good electrolyte infiltration,uniform lithium deposition,and efficient polysulfide shuttling inhibition,is proposed.The separator is composed of polyacrylonitrile(PAN)fiber and decabromodiphenyl ethane(DBDPE)membrane as well as functional layers of boron nitride(BN)for suppressing lithium dendrite growth and reduced graphene oxide(rGO)for accelerating the sulfur convention kinetics.As a result,the Li-S battery with a sulfur mass loading of2.7 mg cm^(-2) delivers a specific capacity of 916.8 mA h g^(-1) after100 cycles at 0.1 C and maintains a stable performance during intermittent thermal shock.Moreover,the Li-S pouch cell with a sulfur mass loading of 8 mg exhibits a high capacity of6.3 mA h under bending conditions.展开更多
In this paper, a partial discharge detection system is proposed using an optical fiber Fabry-Perot(FP) interferometric sensor, which is fabricated by photolithography. SU-8 photoresist is employed due to its low Young...In this paper, a partial discharge detection system is proposed using an optical fiber Fabry-Perot(FP) interferometric sensor, which is fabricated by photolithography. SU-8 photoresist is employed due to its low Young's modulus and potentially high sensitivity for ultrasound detection. The FP cavity is formed by coating the fiber end face with two layers of SU-8 so that the cavity can be controlled by the thickness of the middle layer of SU-8. Static pressure measurement experiments are done to estimate the sensing performance. The results show that the SU-8 based sensor has a sensitivity of 154.8 nm/kP a, which is much higher than that of silica based sensor under the same condition. Moreover, the sensor is demonstrated successfully to detect ultrasound from electrode discharge.展开更多
基金support from the National Natural Science Foundation of China(52072205)the National Key Research and Development Program of China(2019YFA0705700,2021YFB2500200)+1 种基金Shenzhen Stabilization Support Program(WDZC20200824091903001)the Start-up Funds of Tsinghua Shenzhen International Graduate School。
文摘Flexible lithium-sulfur(Li-S)batteries are considered one of the most promising candidates for highenergy-density storage devices in wearable electronics.However,the safety problem severely restricts the practical application of Li-S batteries because of the possible occurrence of thermal runaway caused by battery short circuits and combustible components,particularly under bending conditions.The development of advanced separators that can suppress lithium dendrite growth and are incombustible is the key to improving the safety of flexible Li-S batteries.In this work,a nonflammable multifunctional Janus separator with self-extinguishing capability,high thermal stability,high thermal conductivity,good electrolyte infiltration,uniform lithium deposition,and efficient polysulfide shuttling inhibition,is proposed.The separator is composed of polyacrylonitrile(PAN)fiber and decabromodiphenyl ethane(DBDPE)membrane as well as functional layers of boron nitride(BN)for suppressing lithium dendrite growth and reduced graphene oxide(rGO)for accelerating the sulfur convention kinetics.As a result,the Li-S battery with a sulfur mass loading of2.7 mg cm^(-2) delivers a specific capacity of 916.8 mA h g^(-1) after100 cycles at 0.1 C and maintains a stable performance during intermittent thermal shock.Moreover,the Li-S pouch cell with a sulfur mass loading of 8 mg exhibits a high capacity of6.3 mA h under bending conditions.
基金supported by the National Basic Research Program of China(No.2012CB723405)the Science and Technology Commission of Shanghai Municipality(Nos.13510500300,14DZ1201403 and 14511105602)
文摘In this paper, a partial discharge detection system is proposed using an optical fiber Fabry-Perot(FP) interferometric sensor, which is fabricated by photolithography. SU-8 photoresist is employed due to its low Young's modulus and potentially high sensitivity for ultrasound detection. The FP cavity is formed by coating the fiber end face with two layers of SU-8 so that the cavity can be controlled by the thickness of the middle layer of SU-8. Static pressure measurement experiments are done to estimate the sensing performance. The results show that the SU-8 based sensor has a sensitivity of 154.8 nm/kP a, which is much higher than that of silica based sensor under the same condition. Moreover, the sensor is demonstrated successfully to detect ultrasound from electrode discharge.
