With the ever-increasing energy density requirements for sulfide-based all-solid-state batteries,lithium metal is regarded as an ideal candidate for anode materials.However,the dynamic degradation of solidsolid contac...With the ever-increasing energy density requirements for sulfide-based all-solid-state batteries,lithium metal is regarded as an ideal candidate for anode materials.However,the dynamic degradation of solidsolid contact between lithium anode and solid electrolyte remains a major challenge for the application of all-solid-state lithium metal batteries(ASSLMBs).The poor solid-solid contact problem is caused by the continuous accumulation of lithium voids,which results from the limited diffusion rate of lithium in the bulk phase.In this study,we design a three-dimensional(3D)lithiophilic graphitized carbon nanotubebased(LNT)interlayer to address interfacial issues.The interlayers effectively regulate lithium stripping and suppress the growth of lithium voids via improved lithium diffusion,leading to a conformal interface during continuous cycling.The lithium metal anode with the interlayer delivers an areal capacity of 12.96 mA h cm^(-2),and when paired with a LiNi_(0.9)Co_(0.05)Mn_(0.05)O_(2)(NCM9)cathode,the battery retains over 91%capacity retention after 100 cycles at room temperature.This work provides an effective strategy for interface stabilization in high-capacity and long-life ASSLMBs.展开更多
目的:探讨原发性开角型青光眼(primary open angle glaucoma,POAG)患者血管内皮功能及血液流变学指标变化及危险因素分析。方法:POAG患者86例作为研究对象(观察组),依据视野缺损程度分为轻度组(n=27)、中度组(n=29)和重度组(n=30),另选...目的:探讨原发性开角型青光眼(primary open angle glaucoma,POAG)患者血管内皮功能及血液流变学指标变化及危险因素分析。方法:POAG患者86例作为研究对象(观察组),依据视野缺损程度分为轻度组(n=27)、中度组(n=29)和重度组(n=30),另选取正常健康体检者30例作为对照组,分析POAG的危险因素及各组间血管内皮功能及血液流变学水平。结果:单因素分析结果指出,对照组与观察组间患者性别比例、平均年龄、酗酒史及心血管病史比较,差异无统计学意义(P>0.05),吸烟史、高血压史、糖尿病史及家族史比较,差异均具有统计学意义(P<0.05);观察组一氧化氮(nitric oxide,NO)水平显著低于对照组,且重度组水平显著低于中度组,重度组及中度组NO水平均显著低于轻度组,差异均有统计学意义(P<0.05);与对照组水平相比,观察组内皮素-1(endothelin-1,ET-1)、血浆粘度(plasma viscosity,PV)、红细胞压积(hematocrit,HCT)及纤维蛋白原(fibrinogen,FIB)水平均显著升高,且重度组ET-1、HCT水平显著高于中度组,重度组及中度组ET-1、HCT水平均显著高于轻度组,重度组PV及FIB水平显著高于轻度组,差异均有统计学意义(P<0.05);Logistic回归分析结果表明,吸烟史、高血压史、糖尿病史、家族史、ET-1、PV、HCT及FIB是原发性青光眼的危险因素,NO是保护因素(P<0.05)。结论:POAG患者存在血管内皮功能损伤及血液流变学异常,吸烟史、高血压史、糖尿病史、家族史均与POAG的发生有关。展开更多
Inspired by the concept of "polymer-in-ceramic",a composite poly(ε-caprolactone)(PCL)/ceramic containing LiTFSI is prepared and investigated as a solid electrolyte for all-solid-state batteries.The composit...Inspired by the concept of "polymer-in-ceramic",a composite poly(ε-caprolactone)(PCL)/ceramic containing LiTFSI is prepared and investigated as a solid electrolyte for all-solid-state batteries.The composite with the optimum concentration of 45 wt% LiTFSI and 75 wt% Li1.5Al0.5Ge1.5(PO4)3(LAGP,NASICON-type structure) exhibits a high ionic conductivity(σi=0.17 mS cm-1) at 30℃,a transference number of 0.30,and is stable up to 5.0 V.The composite electrolyte is a flexible and self-standing membrane.Solid-state LiFePO4//Li batteries with this composite electrolyte demonstrate excellent cycling stability with high discharge capacity of 157 mA h g-1,high capacity retention of 96% and coulombic efficiency of 98.5% after 130 cycles at 30℃ and 0.1 C rate.These electrochemical properties are better than other PCL-based allsolid-lithium batteries,and validate the concept of "polymer-in-ceramic" by avoiding the drawback of lower conductivity in prior "polymer-in-ceramic" electrolyte at high concentration of the ceramic.展开更多
Succinonitrile-based plastic crystal electrolytes have emerged for high-energy-density Li metal batteries in terms of their superior ambient ionic conductivity,low flammability,and benign compatibility with high volta...Succinonitrile-based plastic crystal electrolytes have emerged for high-energy-density Li metal batteries in terms of their superior ambient ionic conductivity,low flammability,and benign compatibility with high voltage cathode,but are hampered by inherent instabilities toward Li anodes.Constructing hierarchical solid electrolytes structure is a fundamental approach to protect Li anode from succinonitrile attacks,with succinonitrile-based oxidation-resistance layer facing high voltage cathode and reduction-tolerant layer contacting Li anode.However,free succinonitrile molecules in succinonitrile-based electrolyte layer can diffuse across the electrolyte/electrolyte interface and further reach Li anode surface during the battery cycle.This chemical“crosstalk”cause reduction-tolerant electrolyte layer to fail to protect the Li anode from the attacks of free succinonitrile molecules.Nano Li_(6.4)La_(3)Zr_(1.4)Ta_(0.6)O_(12)is introduced creatively into succinonitrile-based electrolyte layer.By taking advantage of the complexation between La atoms in Li_(6.4)La_(3)Zr_(1.4)Ta_(0.6)O_(12)and N atoms in succinonitrile,the free succinonitrile molecules are successfully immobilized in succinonitrile-based electrolyte layer.The resulting low resistance and highly durable solid electrolyte interphase and cathode electrolyte interphase endow NCM622||Li batteries with remarkable cycle stability.Our research provides a new idea for the real application of plastic crystal electrolytes in high voltage solid-state lithium metal batteries.展开更多
To reduce inter-symbol-interference (ISI) in underwater acoustic (UWA) communication systems, a method based on LDPC-QPSK joint iteration and Walsh-m composite sequence is proposed in this paper. The method is intende...To reduce inter-symbol-interference (ISI) in underwater acoustic (UWA) communication systems, a method based on LDPC-QPSK joint iteration and Walsh-m composite sequence is proposed in this paper. The method is intended for use in long-range and low signal-to-noise ratio (SNR) UWA communications. At the transmitter, Walsh-m composite sequence is introduced to resist multipath effect. At the receiver, a soft-input soft-output (SISO) module is implemented in a joint iterative process between QPSK demodulator and LDPC decoder. This method is demonstrated in three types of UWA channel models: positive, negative and invariable sound velocity gradients channels. It is shown that through contrastive simulation experiments, this method is more efficient than conventional methods based on independent decoding and demodulation. After two rounds of joint iteration, the proposed method can obtain 2.5 dB over conventional method at BER of 10-5. Numerical results verify that the proposed method is a good candidate for long-range underwater acoustic communication systems.展开更多
Aimed at the conventional serial communication system fails when the channel was frequency-selective,long delay and multi-paths effect,resulting in inter-symbol-interference( ISI),an iterative system for underwater ac...Aimed at the conventional serial communication system fails when the channel was frequency-selective,long delay and multi-paths effect,resulting in inter-symbol-interference( ISI),an iterative system for underwater acoustic communication( UWAC) was proposed,which employed iterative differential detection and spread spectrum technique. The proposed scheme adopts π /4-DQPSK soft demodulation to overcome the difficulty of phase ambiguity. For suppression of ISI in UWAC,joint demodulation and decoding iteration was used. The communication scheme has the characteristic of long communication range at low SNR,and the maximum range is up to 100 km. The theoretic analysis and simulation results show that the proposed scheme outperforms traditional serial one. When SNR is- 6 dB,after four joint iterations,compared with serial scheme,BER can decrease from 10- 2to 10- 5.展开更多
基金the Shanxi Province Science Foundation(20210302123150)the National Key Research and Development Program(2021YFB2500300)+3 种基金the National Natural Science Foundation of China(223B1012,22409114)the Beijing Natural Science Foundation(L243019)the Anhui Science and Technology Innovation Tackling Key Problems Plan Project(202423h08050005)the China Postdoctoral Science Foundation(2023M731920)。
文摘With the ever-increasing energy density requirements for sulfide-based all-solid-state batteries,lithium metal is regarded as an ideal candidate for anode materials.However,the dynamic degradation of solidsolid contact between lithium anode and solid electrolyte remains a major challenge for the application of all-solid-state lithium metal batteries(ASSLMBs).The poor solid-solid contact problem is caused by the continuous accumulation of lithium voids,which results from the limited diffusion rate of lithium in the bulk phase.In this study,we design a three-dimensional(3D)lithiophilic graphitized carbon nanotubebased(LNT)interlayer to address interfacial issues.The interlayers effectively regulate lithium stripping and suppress the growth of lithium voids via improved lithium diffusion,leading to a conformal interface during continuous cycling.The lithium metal anode with the interlayer delivers an areal capacity of 12.96 mA h cm^(-2),and when paired with a LiNi_(0.9)Co_(0.05)Mn_(0.05)O_(2)(NCM9)cathode,the battery retains over 91%capacity retention after 100 cycles at room temperature.This work provides an effective strategy for interface stabilization in high-capacity and long-life ASSLMBs.
基金supported by the National Key R&D Program of China (2016YFB0100500)Special fund of key technology research and development projects (20180201097GX) (20180201099GX) (20180201096GX) (20190302130GX)+1 种基金Jilin province science and technology department. The R&D Program of power batteries with low temperature and high energy, Science and Technology Bureau of Changchun (19SS013)Key Subject Construction of Physical Chemistry of Northeast Normal University。
文摘Inspired by the concept of "polymer-in-ceramic",a composite poly(ε-caprolactone)(PCL)/ceramic containing LiTFSI is prepared and investigated as a solid electrolyte for all-solid-state batteries.The composite with the optimum concentration of 45 wt% LiTFSI and 75 wt% Li1.5Al0.5Ge1.5(PO4)3(LAGP,NASICON-type structure) exhibits a high ionic conductivity(σi=0.17 mS cm-1) at 30℃,a transference number of 0.30,and is stable up to 5.0 V.The composite electrolyte is a flexible and self-standing membrane.Solid-state LiFePO4//Li batteries with this composite electrolyte demonstrate excellent cycling stability with high discharge capacity of 157 mA h g-1,high capacity retention of 96% and coulombic efficiency of 98.5% after 130 cycles at 30℃ and 0.1 C rate.These electrochemical properties are better than other PCL-based allsolid-lithium batteries,and validate the concept of "polymer-in-ceramic" by avoiding the drawback of lower conductivity in prior "polymer-in-ceramic" electrolyte at high concentration of the ceramic.
基金supported by R&D Program of Power Batteries with Low Temperature and High Energy,Science and Technology Bureau of Changchun(19SS013)Key Subject Construction of Physical Chemistry of Northeast Normal University+1 种基金the Fundamental Research Funds for the Central Universities(2412020FZ007,2412020FZ008)National Natural Science Foundation of China(22102020).
文摘Succinonitrile-based plastic crystal electrolytes have emerged for high-energy-density Li metal batteries in terms of their superior ambient ionic conductivity,low flammability,and benign compatibility with high voltage cathode,but are hampered by inherent instabilities toward Li anodes.Constructing hierarchical solid electrolytes structure is a fundamental approach to protect Li anode from succinonitrile attacks,with succinonitrile-based oxidation-resistance layer facing high voltage cathode and reduction-tolerant layer contacting Li anode.However,free succinonitrile molecules in succinonitrile-based electrolyte layer can diffuse across the electrolyte/electrolyte interface and further reach Li anode surface during the battery cycle.This chemical“crosstalk”cause reduction-tolerant electrolyte layer to fail to protect the Li anode from the attacks of free succinonitrile molecules.Nano Li_(6.4)La_(3)Zr_(1.4)Ta_(0.6)O_(12)is introduced creatively into succinonitrile-based electrolyte layer.By taking advantage of the complexation between La atoms in Li_(6.4)La_(3)Zr_(1.4)Ta_(0.6)O_(12)and N atoms in succinonitrile,the free succinonitrile molecules are successfully immobilized in succinonitrile-based electrolyte layer.The resulting low resistance and highly durable solid electrolyte interphase and cathode electrolyte interphase endow NCM622||Li batteries with remarkable cycle stability.Our research provides a new idea for the real application of plastic crystal electrolytes in high voltage solid-state lithium metal batteries.
基金Sponsored by the Fundamental Research Funds for the Central Universities(Grant No.HEUCF120814)
文摘To reduce inter-symbol-interference (ISI) in underwater acoustic (UWA) communication systems, a method based on LDPC-QPSK joint iteration and Walsh-m composite sequence is proposed in this paper. The method is intended for use in long-range and low signal-to-noise ratio (SNR) UWA communications. At the transmitter, Walsh-m composite sequence is introduced to resist multipath effect. At the receiver, a soft-input soft-output (SISO) module is implemented in a joint iterative process between QPSK demodulator and LDPC decoder. This method is demonstrated in three types of UWA channel models: positive, negative and invariable sound velocity gradients channels. It is shown that through contrastive simulation experiments, this method is more efficient than conventional methods based on independent decoding and demodulation. After two rounds of joint iteration, the proposed method can obtain 2.5 dB over conventional method at BER of 10-5. Numerical results verify that the proposed method is a good candidate for long-range underwater acoustic communication systems.
基金Sponsored by the Advanced Research Project of"Twelve-Five-Year-Plan"of Weapon System(Grant No.4010201050201)the China Postdoctoral Science Foundation Founded Project(Grant No.2011M500640)+1 种基金the Postdoctoral Science Foundation of Heilongjiang Province(Grant No.LBHZ10206)the China Fundamental Research Funds for the Central Universities(Grant No.HEUCF130802)
文摘Aimed at the conventional serial communication system fails when the channel was frequency-selective,long delay and multi-paths effect,resulting in inter-symbol-interference( ISI),an iterative system for underwater acoustic communication( UWAC) was proposed,which employed iterative differential detection and spread spectrum technique. The proposed scheme adopts π /4-DQPSK soft demodulation to overcome the difficulty of phase ambiguity. For suppression of ISI in UWAC,joint demodulation and decoding iteration was used. The communication scheme has the characteristic of long communication range at low SNR,and the maximum range is up to 100 km. The theoretic analysis and simulation results show that the proposed scheme outperforms traditional serial one. When SNR is- 6 dB,after four joint iterations,compared with serial scheme,BER can decrease from 10- 2to 10- 5.
