聚合的分布式能源可作为虚拟电厂(virtual power plant,VPP)在电力市场中提供辅助调频服务,来应对低碳经济下大规模可再生能源并网给电力系统稳定性带来的挑战。为了引导VPP参与调频辅助服务市场,对VPP所有者的经济激励尤为重要。研究...聚合的分布式能源可作为虚拟电厂(virtual power plant,VPP)在电力市场中提供辅助调频服务,来应对低碳经济下大规模可再生能源并网给电力系统稳定性带来的挑战。为了引导VPP参与调频辅助服务市场,对VPP所有者的经济激励尤为重要。研究了澳大利亚国家电力市场中调频辅助服务市场机制,针对配网侧聚合的住宅屋顶光伏和电池储能系统的VPP,以利润最大化为目标,提出了嵌入电池循环寿命模型的调频市场优化竞标策略和与风电合作的联合优化竞标策略。同时,根据讨价还价博弈理论,基于Nash–Harsanyi 讨价还价解提出了一种反映VPP真实价值的合作剩余分配策略。算例结果验证了所提模型和方法的有效性,研究成果为激发VPP潜在价值提供了一条途径。展开更多
Lithium nickel oxide(Li_(2)NiO_(2)),as a sacrificial cathode prelithiation additive,has been used to compensate for the lithium loss for improving the lifespan of lithium-ion batteries(LIBs).However,high-cost Li_(2)Ni...Lithium nickel oxide(Li_(2)NiO_(2)),as a sacrificial cathode prelithiation additive,has been used to compensate for the lithium loss for improving the lifespan of lithium-ion batteries(LIBs).However,high-cost Li_(2)NiO_(2)suffers from inferior delithiation kinetics during the first cycle.Herein,we investigated the effects of the cost-effective copper substituted Li_(2)Ni_(1-x)Cu_(x)O_(2)(x=0,0.2,0.3,0.5,0.7)synthesized by a high-temperature solid-phase method on the structure,morphology,electrochemical performance of graphite‖LiFePO_(4)battery.The X-ray diffraction(XRD)refinement result demonstrated that Cu substitution strategy could be favorable for eliminating the NiO_(x)impurity phase and weakening Li-O bond.Analysis on density of states(DOS)indicates that Cu substitution is good for enhancing the electronic conductivity,as well as reducing the delithi-ation voltage polarization confirmed by electrochemical characterizations.Therefore,the optimal Li_(2)Ni_(0.7)Cu_(0.3)O_(2)delivered a high delithiation capacity of 437 mAh·g^(-1),around 8%above that of the pristine Li_(2)NiO_(2).Furthermore,a graphite‖LiFePO_(4)pouch cell with a nominal capacity of 3000 mAh demonstrated a notably improved reversible capacity,energy density and cycle life through introducing 2 wt%Li_(2)Ni_(0.7)Cu_(0.3)O_(2)additive,delivering a 6.2 mAh·g^(-1)higher initial discharge capacity and achieving around 5%improvement in capacity retentnion at 0.5P over 1000 cycles.Additionally,the post-mortem analyses testified that the Li_(2)Ni_(0.7)Cu_(0.3)O_(2)additive could suppress solid electrolyte interphase(SEI)decomposition and homogenize the Li distribution,which benefits to stabilizing interface between graphite and electrolyte,and alleviating dendritic Li plating.In conclusion,the Li_(2)Ni_(0.7)Cu_(0.3)O_(2)additive may offer advantages such as lower cost,lower delithiation voltage and higher prelithiation capacity compared with Li_(2)NiO_(2),making it a promising candidate of cathode prelithiation additive for next-generation LIBs.展开更多
As a negative electrode material for lithium-ion batteries,silicon monoxide(SiO)suffers from dramatic volume changes during cycling,causing excessive stress within the electrode and resulting in electrode deformation ...As a negative electrode material for lithium-ion batteries,silicon monoxide(SiO)suffers from dramatic volume changes during cycling,causing excessive stress within the electrode and resulting in electrode deformation and fragmentation.This ultimately leads to a decrease in cell capacity.The trends of volume expansion and capacity change of the SiO/graphite(SiO/C)composite electrode during cycling were investigated via in situ expansion monitoring.First,a series of expansion test schemes were designed,and the linear relationship between negative electrode expansion and cell capacity degradation was quantitatively analyzed.Then,the effects of different initial pressures on the long-term cycling performance of the cell were evaluated.Finally,the mechanism of their effects was analyzed by scanning electron microscope.The results show that after 50 cycles,the cell capacity decreases from 2.556 mAh to 1.689 mAh,with a capacity retention ratio(CRR)of only 66.08%.A linear relationship between the capacity retention ratio and thickness expansion was found.Electrochemical measurements and scanning electron microscope images demonstrate that intense stress inhibits the lithiation of the negative electrode and that the electrode is more susceptible to irreversible damage during cycling.Overall,these results reveal the relationship between the cycling performance of SiO and the internal pressure of the electrode from a macroscopic point of view,which provides some reference for the application of SiO/C composite electrodes in lithium-ion batteries.展开更多
文摘聚合的分布式能源可作为虚拟电厂(virtual power plant,VPP)在电力市场中提供辅助调频服务,来应对低碳经济下大规模可再生能源并网给电力系统稳定性带来的挑战。为了引导VPP参与调频辅助服务市场,对VPP所有者的经济激励尤为重要。研究了澳大利亚国家电力市场中调频辅助服务市场机制,针对配网侧聚合的住宅屋顶光伏和电池储能系统的VPP,以利润最大化为目标,提出了嵌入电池循环寿命模型的调频市场优化竞标策略和与风电合作的联合优化竞标策略。同时,根据讨价还价博弈理论,基于Nash–Harsanyi 讨价还价解提出了一种反映VPP真实价值的合作剩余分配策略。算例结果验证了所提模型和方法的有效性,研究成果为激发VPP潜在价值提供了一条途径。
基金supported by the Significant Science and Technology Project in Xiamen(Future Industry Field)(Grant No.3502Z20231057).
文摘Lithium nickel oxide(Li_(2)NiO_(2)),as a sacrificial cathode prelithiation additive,has been used to compensate for the lithium loss for improving the lifespan of lithium-ion batteries(LIBs).However,high-cost Li_(2)NiO_(2)suffers from inferior delithiation kinetics during the first cycle.Herein,we investigated the effects of the cost-effective copper substituted Li_(2)Ni_(1-x)Cu_(x)O_(2)(x=0,0.2,0.3,0.5,0.7)synthesized by a high-temperature solid-phase method on the structure,morphology,electrochemical performance of graphite‖LiFePO_(4)battery.The X-ray diffraction(XRD)refinement result demonstrated that Cu substitution strategy could be favorable for eliminating the NiO_(x)impurity phase and weakening Li-O bond.Analysis on density of states(DOS)indicates that Cu substitution is good for enhancing the electronic conductivity,as well as reducing the delithi-ation voltage polarization confirmed by electrochemical characterizations.Therefore,the optimal Li_(2)Ni_(0.7)Cu_(0.3)O_(2)delivered a high delithiation capacity of 437 mAh·g^(-1),around 8%above that of the pristine Li_(2)NiO_(2).Furthermore,a graphite‖LiFePO_(4)pouch cell with a nominal capacity of 3000 mAh demonstrated a notably improved reversible capacity,energy density and cycle life through introducing 2 wt%Li_(2)Ni_(0.7)Cu_(0.3)O_(2)additive,delivering a 6.2 mAh·g^(-1)higher initial discharge capacity and achieving around 5%improvement in capacity retentnion at 0.5P over 1000 cycles.Additionally,the post-mortem analyses testified that the Li_(2)Ni_(0.7)Cu_(0.3)O_(2)additive could suppress solid electrolyte interphase(SEI)decomposition and homogenize the Li distribution,which benefits to stabilizing interface between graphite and electrolyte,and alleviating dendritic Li plating.In conclusion,the Li_(2)Ni_(0.7)Cu_(0.3)O_(2)additive may offer advantages such as lower cost,lower delithiation voltage and higher prelithiation capacity compared with Li_(2)NiO_(2),making it a promising candidate of cathode prelithiation additive for next-generation LIBs.
基金supported by the Fundamental Research Funds for the Central Universities(WK2090000055)Anhui Provincial Natural Science Foundation of China(2308085QG231).
文摘As a negative electrode material for lithium-ion batteries,silicon monoxide(SiO)suffers from dramatic volume changes during cycling,causing excessive stress within the electrode and resulting in electrode deformation and fragmentation.This ultimately leads to a decrease in cell capacity.The trends of volume expansion and capacity change of the SiO/graphite(SiO/C)composite electrode during cycling were investigated via in situ expansion monitoring.First,a series of expansion test schemes were designed,and the linear relationship between negative electrode expansion and cell capacity degradation was quantitatively analyzed.Then,the effects of different initial pressures on the long-term cycling performance of the cell were evaluated.Finally,the mechanism of their effects was analyzed by scanning electron microscope.The results show that after 50 cycles,the cell capacity decreases from 2.556 mAh to 1.689 mAh,with a capacity retention ratio(CRR)of only 66.08%.A linear relationship between the capacity retention ratio and thickness expansion was found.Electrochemical measurements and scanning electron microscope images demonstrate that intense stress inhibits the lithiation of the negative electrode and that the electrode is more susceptible to irreversible damage during cycling.Overall,these results reveal the relationship between the cycling performance of SiO and the internal pressure of the electrode from a macroscopic point of view,which provides some reference for the application of SiO/C composite electrodes in lithium-ion batteries.
