Graphite,encompassing both natural graphite and synthetic graphite,and graphene,have been extensively utilized and investigated as anode materials and additives in lithium-ion batteries(LIBs).In the pursuit of carbon ...Graphite,encompassing both natural graphite and synthetic graphite,and graphene,have been extensively utilized and investigated as anode materials and additives in lithium-ion batteries(LIBs).In the pursuit of carbon neutrality,LIBs are expected to play a pivotal role in reducing CO_(2)emissions by decreasing reliance on fossil fuels and enabling the integration of renewable energy sources.Owing to their technological maturity and exceptional electrochemical performance,the global production of graphite and graphene for LIBs is projected to continue expanding.Over the past decades,numerous researchers have concentrated on reducing the material and energy input whilst optimising the electrochemical performance of graphite and graphene,through novel synthesis methods and various modifications at the laboratory scale.This review provides a comprehensive examination of the manufacturing methods,environmental impact,research progress,and challenges associated with graphite and graphene in LIBs from an industrial perspective,with a particular focus on the carbon footprint of production processes.Additionally,it considers emerging challenges and future development directions of graphite and graphene,offering significant insights for ongoing and future research in the field of green LIBs.展开更多
Fine-grained nuclear graphite is a key material in high-temperature gas-cooled reactors(HTGRs).During air ingress accidents,core graphite components undergo severe oxidation,threatening structural integrity.Therefore,...Fine-grained nuclear graphite is a key material in high-temperature gas-cooled reactors(HTGRs).During air ingress accidents,core graphite components undergo severe oxidation,threatening structural integrity.Therefore,understanding the oxidation behavior of nuclear graphite is essential for reactor safety.The influence of oxidation involves multiple factors,including temperature,sample size,oxidant,impurities,filler type and size,etc.The size of the filler particles plays a crucial role in this study.Five ultrafine-and superfine-grained nuclear graphite samples(5.9-34.4μm)are manufactured using identical raw materials and manufacturing processes.Isothermal oxidation tests conducted at 650℃-750℃ are used to study the oxidation behavior.Additionally,comprehensive characterization is performed to analyze the crystal structure,surface morphology,and nanoscale to microscale pore structure of the samples.Results indicate that oxidation behavior cannot be predicted solely based on filler grain size.Reactive site concentration,characterized by active surface area,dominates the chemical reaction kinetics,whereas pore tortuosity,quantified by the structural parameterΨ,plays a key role in regulating oxidant diffusion.These findings clarify the dual role of microstructure in oxidation mechanisms and establish a theoretical and experimental basis for the design of high-performance nuclear graphite capable of long-term service in high-temperature gas-cooled reactors.展开更多
In order to effectively prevent the contamination of carbon particle volatiles during high-purity SiC crystals are prepared using the physical vapor transport(PVT)method in ultra-high temperature environments(T³2...In order to effectively prevent the contamination of carbon particle volatiles during high-purity SiC crystals are prepared using the physical vapor transport(PVT)method in ultra-high temperature environments(T³2000℃),this study innovatively attempts to protect graphite materials with SiC reinforced pyrolytic graphite(PyG)coating.It is discovered by preparing the SiC particle layer,the degree of graphitization and stability of PyG coating can be improved.The corrosion test results demonstrated that the SiC reinforced PyG coating can maintain an intact coating with a high graphitization degree after the SiC vapour corrosion test of 2050℃-120 h.Conversely,the samples with and without PyG coating reveal porous and eroded surfaces.Furthermore,following the SiC vapour corrosion test,the PyG coating sample’s integral ratio of D-band and G-band(I_(D)/I_(G))of Raman spectrum test data,reduced by 6.5%,while the SiC reinforced PyG coating decreased by 17.2%,indicating its excellent corrosion resistance.The application of SiC reinforced pyrolytic graphite coating in preparing the SiC single crystal might received a theoretical foundation according to this work.展开更多
To enhance the electrochemical performance of lithium-ion battery anodes with higher silicon content,it is essential to engineer their microstructure for better lithium-ion transport and mitigated volume change as wel...To enhance the electrochemical performance of lithium-ion battery anodes with higher silicon content,it is essential to engineer their microstructure for better lithium-ion transport and mitigated volume change as well.Herein,we suggest an effective approach to control the micropore structure of silicon oxide(SiO_(x))/artificial graphite(AG)composite electrodes using a perforated current collector.The electrode features a unique pore structure,where alternating high-porosity domains and low-porosity domains markedly reduce overall electrode resistance,leading to a 20%improvement in rate capability at a 5C-rate discharge condition.Using microstructure-resolved modeling and simulations,we demonstrate that the patterned micropore structure enhances lithium-ion transport,mitigating the electrolyte concentration gradient of lithium-ion.Additionally,perforating current collector with a chemical etching process increases the number of hydrogen bonding sites and enlarges the interface with the SiO_(x)/AG composite electrode,significantly improving adhesion strength.This,in turn,suppresses mechanical degradation and leads to a 50%higher capacity retention.Thus,regularly arranged micropore structure enabled by the perforated current collector successfully improves both rate capability and cycle life in SiO_(x)/AG composite electrodes,providing valuable insights into electrode engineering.展开更多
Waste graphitization cathode carbon blocks are a type of hazardous solid waste generated during the aluminum electrolysis process,and their proper disposal is a key step in the resource utilization of discarded graphi...Waste graphitization cathode carbon blocks are a type of hazardous solid waste generated during the aluminum electrolysis process,and their proper disposal is a key step in the resource utilization of discarded graphite.This study utilizes the porous“defect advantage”of a cathode carbon block matrix to prepare silicon-doped and asphalt-coated detoxified and purified waste graphitization cathode carbon blocks for use as high-performance silicon/carbon composite anode materials.The results show that the uniformly silicondoped silicon/carbon composite material features a unique amorphous carbon-encapsulated“locked silicon”structure,which effectively addresses issues such as cathode volume expansion,excessive growth of the solid electrolyte interphase(SEI)film,and poor electrical contact between active materials.Consequently,electrochemical performance is enhanced.After assembly in a half-cell,the PSCC/10%Si@C(purified waste graphitization cathode carbon/10%Si@C)material exhibits optimal electrochemical stability,with an initial charging specific capacity of 514.5 mAh/g at 0.1 C(1 C=170 mA/g)and a capacity retention rate of 95.1%after 100 cycles.At a charge rate of 2.0 C,a specific capacity of 216.9 mAh/g is achieved.This technology provides a new pathway for the economical and high-value utilization of waste cathode carbon blocks and the development of low-cost,high-performance anode materials.展开更多
卵巢衰老分为生理性与病理性两类,表现为卵巢储备功能下降、卵泡数量减少和激素水平紊乱,并与多种慢性疾病风险相关。研究发现,免疫失衡在卵巢衰老中扮演核心角色,尤其是辅助性T细胞17(helper T cell 17,Th17细胞)与调节性T细胞(regulat...卵巢衰老分为生理性与病理性两类,表现为卵巢储备功能下降、卵泡数量减少和激素水平紊乱,并与多种慢性疾病风险相关。研究发现,免疫失衡在卵巢衰老中扮演核心角色,尤其是辅助性T细胞17(helper T cell 17,Th17细胞)与调节性T细胞(regulatory T cell,Treg细胞)的比例失调。Th17/Treg平衡受炎症因子、核因子κB(nuclear factor-κB,NF-κB)通路及哺乳动物雷帕霉素靶蛋白(mammalian target of rapamycin,mTOR)通路的精密调控,其失衡会加剧卵巢局部炎症,加速卵泡耗竭。目前,针对Th17/Treg比例失衡的干预策略在自身免疫性疾病的治疗中已取得进展,为卵巢衰老的临床干预提供了新思路。综述Th17/Treg比例失衡在卵巢衰老中的核心作用,为探索延缓卵巢衰老的免疫治疗策略提供了理论依据。展开更多
目的 探讨肺结核(tuberculosis, TB)患者血清中涎液化糖链抗原(krebs von den lungen-6, KL-6)、T细胞免疫球蛋白及粘蛋白域蛋白-4(T-cell immunoglobulin and mucin domain-containing molecule-4, TIM-4)水平与病情程度及不良预后的...目的 探讨肺结核(tuberculosis, TB)患者血清中涎液化糖链抗原(krebs von den lungen-6, KL-6)、T细胞免疫球蛋白及粘蛋白域蛋白-4(T-cell immunoglobulin and mucin domain-containing molecule-4, TIM-4)水平与病情程度及不良预后的关系。方法 选取2021年7月至2023年7月期间在江苏省人民医院溧阳分院诊治的158例TB患者为观察组,并选取同期在我院进行健康体检的158例健康者作为对照组。采用Bandim结核病评分标准对TB患者病情程度进行评估,将其分为重症组(n=61)和轻症组(n=97);根据患者预后情况,分为良好组(n=101)与不良组(n=57);采用Logistic回归分析TB患者预后影响因素;通过Spearman相关分析评估血清KL-6和TIM-4水平与TB病情程度的相关性;利用受试者工作特征曲线评价血清KL-6和TIM-4对TB患者预后的预测效能。结果 观察组血清KL-6和TIM-4水平均显著高于对照组(均P<0.05);与轻症组相比,重症组血清KL-6和TIM-4水平均明显升高(均P<0.05);不良组血清KL-6和TIM-4水平均明显高于预后良好组(均P<0.05);血清KL-6、TIM-4水平均是TB患者不良预后的独立影响因素(均P<0.05);血清KL-6、TIM-4预测TB患者预后的曲线下面积(area under curve, AUC)分别为0.789、0.803,2者联合预测的AUC为0.914,2者联合预测效能优于任一单一指标(z2者联合-KL-6=3.375,P=0.001;z2者联合-TIM-4=3.514,P=0.000)。结论 TB患者血清KL-6、TIM-4水平升高,与患者病情严重程度及不良预后密切相关,且2者联合预测对TB患者不良预后具有较高的预测价值。展开更多
基金supported by European Union's Horizon Europe,UK Research and Innovation(UKRI).
文摘Graphite,encompassing both natural graphite and synthetic graphite,and graphene,have been extensively utilized and investigated as anode materials and additives in lithium-ion batteries(LIBs).In the pursuit of carbon neutrality,LIBs are expected to play a pivotal role in reducing CO_(2)emissions by decreasing reliance on fossil fuels and enabling the integration of renewable energy sources.Owing to their technological maturity and exceptional electrochemical performance,the global production of graphite and graphene for LIBs is projected to continue expanding.Over the past decades,numerous researchers have concentrated on reducing the material and energy input whilst optimising the electrochemical performance of graphite and graphene,through novel synthesis methods and various modifications at the laboratory scale.This review provides a comprehensive examination of the manufacturing methods,environmental impact,research progress,and challenges associated with graphite and graphene in LIBs from an industrial perspective,with a particular focus on the carbon footprint of production processes.Additionally,it considers emerging challenges and future development directions of graphite and graphene,offering significant insights for ongoing and future research in the field of green LIBs.
基金supported by the National Key Research and Development Program of China(2024YFA1612900)the National Natural Science Foundation of China(Grant No.52103365 and No.12375270)the Guangdong Innovative and Entrepreneurial Research Team Program,China(Grant No.2021ZT09L227).
文摘Fine-grained nuclear graphite is a key material in high-temperature gas-cooled reactors(HTGRs).During air ingress accidents,core graphite components undergo severe oxidation,threatening structural integrity.Therefore,understanding the oxidation behavior of nuclear graphite is essential for reactor safety.The influence of oxidation involves multiple factors,including temperature,sample size,oxidant,impurities,filler type and size,etc.The size of the filler particles plays a crucial role in this study.Five ultrafine-and superfine-grained nuclear graphite samples(5.9-34.4μm)are manufactured using identical raw materials and manufacturing processes.Isothermal oxidation tests conducted at 650℃-750℃ are used to study the oxidation behavior.Additionally,comprehensive characterization is performed to analyze the crystal structure,surface morphology,and nanoscale to microscale pore structure of the samples.Results indicate that oxidation behavior cannot be predicted solely based on filler grain size.Reactive site concentration,characterized by active surface area,dominates the chemical reaction kinetics,whereas pore tortuosity,quantified by the structural parameterΨ,plays a key role in regulating oxidant diffusion.These findings clarify the dual role of microstructure in oxidation mechanisms and establish a theoretical and experimental basis for the design of high-performance nuclear graphite capable of long-term service in high-temperature gas-cooled reactors.
基金Project(U19A2099)supported by the National Natural Science Foundation of China。
文摘In order to effectively prevent the contamination of carbon particle volatiles during high-purity SiC crystals are prepared using the physical vapor transport(PVT)method in ultra-high temperature environments(T³2000℃),this study innovatively attempts to protect graphite materials with SiC reinforced pyrolytic graphite(PyG)coating.It is discovered by preparing the SiC particle layer,the degree of graphitization and stability of PyG coating can be improved.The corrosion test results demonstrated that the SiC reinforced PyG coating can maintain an intact coating with a high graphitization degree after the SiC vapour corrosion test of 2050℃-120 h.Conversely,the samples with and without PyG coating reveal porous and eroded surfaces.Furthermore,following the SiC vapour corrosion test,the PyG coating sample’s integral ratio of D-band and G-band(I_(D)/I_(G))of Raman spectrum test data,reduced by 6.5%,while the SiC reinforced PyG coating decreased by 17.2%,indicating its excellent corrosion resistance.The application of SiC reinforced pyrolytic graphite coating in preparing the SiC single crystal might received a theoretical foundation according to this work.
基金supported by the National Research Foundation of Korea(NRF)grant funded by the Korean government(MSIT)(No.NRF-2021M3H4A1A02048529)the Ministry of Trade,Industry and Energy(MOTIE)of the Korean government under grant No.RS-2022-00155854support from the DGIST Supercomputing and Big Data Center.
文摘To enhance the electrochemical performance of lithium-ion battery anodes with higher silicon content,it is essential to engineer their microstructure for better lithium-ion transport and mitigated volume change as well.Herein,we suggest an effective approach to control the micropore structure of silicon oxide(SiO_(x))/artificial graphite(AG)composite electrodes using a perforated current collector.The electrode features a unique pore structure,where alternating high-porosity domains and low-porosity domains markedly reduce overall electrode resistance,leading to a 20%improvement in rate capability at a 5C-rate discharge condition.Using microstructure-resolved modeling and simulations,we demonstrate that the patterned micropore structure enhances lithium-ion transport,mitigating the electrolyte concentration gradient of lithium-ion.Additionally,perforating current collector with a chemical etching process increases the number of hydrogen bonding sites and enlarges the interface with the SiO_(x)/AG composite electrode,significantly improving adhesion strength.This,in turn,suppresses mechanical degradation and leads to a 50%higher capacity retention.Thus,regularly arranged micropore structure enabled by the perforated current collector successfully improves both rate capability and cycle life in SiO_(x)/AG composite electrodes,providing valuable insights into electrode engineering.
基金supported by the National Natural Science Foundation of China(No.52274346).
文摘Waste graphitization cathode carbon blocks are a type of hazardous solid waste generated during the aluminum electrolysis process,and their proper disposal is a key step in the resource utilization of discarded graphite.This study utilizes the porous“defect advantage”of a cathode carbon block matrix to prepare silicon-doped and asphalt-coated detoxified and purified waste graphitization cathode carbon blocks for use as high-performance silicon/carbon composite anode materials.The results show that the uniformly silicondoped silicon/carbon composite material features a unique amorphous carbon-encapsulated“locked silicon”structure,which effectively addresses issues such as cathode volume expansion,excessive growth of the solid electrolyte interphase(SEI)film,and poor electrical contact between active materials.Consequently,electrochemical performance is enhanced.After assembly in a half-cell,the PSCC/10%Si@C(purified waste graphitization cathode carbon/10%Si@C)material exhibits optimal electrochemical stability,with an initial charging specific capacity of 514.5 mAh/g at 0.1 C(1 C=170 mA/g)and a capacity retention rate of 95.1%after 100 cycles.At a charge rate of 2.0 C,a specific capacity of 216.9 mAh/g is achieved.This technology provides a new pathway for the economical and high-value utilization of waste cathode carbon blocks and the development of low-cost,high-performance anode materials.
文摘卵巢衰老分为生理性与病理性两类,表现为卵巢储备功能下降、卵泡数量减少和激素水平紊乱,并与多种慢性疾病风险相关。研究发现,免疫失衡在卵巢衰老中扮演核心角色,尤其是辅助性T细胞17(helper T cell 17,Th17细胞)与调节性T细胞(regulatory T cell,Treg细胞)的比例失调。Th17/Treg平衡受炎症因子、核因子κB(nuclear factor-κB,NF-κB)通路及哺乳动物雷帕霉素靶蛋白(mammalian target of rapamycin,mTOR)通路的精密调控,其失衡会加剧卵巢局部炎症,加速卵泡耗竭。目前,针对Th17/Treg比例失衡的干预策略在自身免疫性疾病的治疗中已取得进展,为卵巢衰老的临床干预提供了新思路。综述Th17/Treg比例失衡在卵巢衰老中的核心作用,为探索延缓卵巢衰老的免疫治疗策略提供了理论依据。
文摘目的 探讨肺结核(tuberculosis, TB)患者血清中涎液化糖链抗原(krebs von den lungen-6, KL-6)、T细胞免疫球蛋白及粘蛋白域蛋白-4(T-cell immunoglobulin and mucin domain-containing molecule-4, TIM-4)水平与病情程度及不良预后的关系。方法 选取2021年7月至2023年7月期间在江苏省人民医院溧阳分院诊治的158例TB患者为观察组,并选取同期在我院进行健康体检的158例健康者作为对照组。采用Bandim结核病评分标准对TB患者病情程度进行评估,将其分为重症组(n=61)和轻症组(n=97);根据患者预后情况,分为良好组(n=101)与不良组(n=57);采用Logistic回归分析TB患者预后影响因素;通过Spearman相关分析评估血清KL-6和TIM-4水平与TB病情程度的相关性;利用受试者工作特征曲线评价血清KL-6和TIM-4对TB患者预后的预测效能。结果 观察组血清KL-6和TIM-4水平均显著高于对照组(均P<0.05);与轻症组相比,重症组血清KL-6和TIM-4水平均明显升高(均P<0.05);不良组血清KL-6和TIM-4水平均明显高于预后良好组(均P<0.05);血清KL-6、TIM-4水平均是TB患者不良预后的独立影响因素(均P<0.05);血清KL-6、TIM-4预测TB患者预后的曲线下面积(area under curve, AUC)分别为0.789、0.803,2者联合预测的AUC为0.914,2者联合预测效能优于任一单一指标(z2者联合-KL-6=3.375,P=0.001;z2者联合-TIM-4=3.514,P=0.000)。结论 TB患者血清KL-6、TIM-4水平升高,与患者病情严重程度及不良预后密切相关,且2者联合预测对TB患者不良预后具有较高的预测价值。