基于KF-BPNN融合算法的电池循环寿命预测方法

为了解决实际应用过程中电池循环寿命预测精度较低的问题,提出卡尔曼滤波-BP神经网络(KF-BPNN)融合算法对电池的循环寿命进行预测。该方法选用电池内阻作为循环寿命的评估参数,利用BPNN预测电池的内阻值,并将预测内阻值作为KF算法的观测值来修正卡尔曼滤波观测方程系数,从而提高循环寿命预测精度。实验结果表明:融合算法的预测精度有了明显提高。

基于电池循环寿命的纯电动汽车续驶里程估算

为了提高纯电动汽车的续驶里程估算精度,降低因电动汽车续驶里程估计不准确而出现的"里程焦虑",提出一种基于电池循环寿命的纯电动汽车续驶里程估算方法。首先,以纯电动汽车的整体性能分析为基础,将汽车续驶里程估算中电池循环使用时长问题,通过卡尔曼滤波算法转化为代价函数逼近最小值问题,确定电池循环使用寿命。其次,通过计算电池组剩余能量和已行驶里程,计算出纯电动汽车单位里程能耗;最后,计算出纯电动汽车循环工况续驶里程。实验结果表明,采用该方法对纯电动汽车续驶里程进行估算准确性较高,估算误差最低为2.5%,提高了对纯电动汽车续驶里程的估算精度。

基于循环寿命的电池冷却策略试验开发

为解决纯电动乘用车使用空调系统为动力电池冷却时整车空调舒适性下降的问题,结合实际开发项目,根据开发车辆销售目标区域确定用户典型出行链,根据出行链制定纯电动乘用车年日历行驶工况,并采用该工况进行整车台架环境模拟试验,完成车辆一年内在行驶、充电和存放3种状态下电池温度分布情况的统计分析,完成电池循环寿命评估,并分解各工况对电池寿命衰减的影响程度占比,对电池冷却系统控制策略进行优化。结果表明:电池冷却过程中冷却系统介入时长占比大幅下降,整车空调舒适性明显提高。

考虑电池寿命的虚拟电厂调频竞标模型及合作利润分配策略

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。

浅析不同热管理对电池寿命的影响

通过对目前国内外汽车行业已投产及在研部分车型的调查,结合日常工作中发现的实际问题,针对这些问题进行了仿真分析及试验验证,根据试验结论阐述不同种类的电池热管理形式的环境适应性以及在不同环境下对电池寿命的具体影响。

充电方式对电动自行车用铅酸电池性能的影响

对电动自行车用铅酸蓄电池充电时的正、负极反应状态作了分析，提出了一种新的充电方式：采用较大的初始充电电流，确保正极活性物质与界面结构的均匀紧密性，采用分步恒流充电，提供较大的充电结束电流，缩短充电时间，同时弥补氧循环消耗的充电电流，在保证正负极充足电的前提下，尽量减少过充量。通过实验分析对比证明：采用分步恒流、大电流结束充电方式的电池循环寿命明显高于传流的恒压限流充电方式的电池。

纯电动汽车电池管理的开发与应用

简要介绍了搭载磷酸铁锂电池的电动汽车电池管理系统与整车的关系,分析了磷酸铁锂电池的充放电特性,阐述了电池管理系统的结构,对于电池电量(SOC)的估算做出阐述,根据应用经验估算出电池可循环使用寿命(SOH),通过大量实验数据说明了电池的充放电特性,这些特性对于电池管理系统的开发具有积极意义。

电动公交客车增程器开关控制策略和等效能耗最小化策略优化

本文中旨在解决增程式电动公交客车单点恒温器能量管理策略下电量维持阶段油耗较高和锂电池组循环充放电深度较大等问题。首先对增程器开关控制策略和等效燃油消耗最小化策略(ECMS)进行优化和仿真验证,然后在增程式电动公交客车半实物仿真平台上进行了试验验证。结果表明:电量维持阶段,优化增程器开关控制策略后,增程式电动公交客车百公里油耗由原来的39. 1降至36. 23L,锂电池组循环充电系数由19. 8/100km降至13. 2/100km,分别降低了7. 3%和33. 3%,但增程器的起停次数有所增加。进一步采用优化的ECMS能量管理策略后,增程式电动公交客车百公里油耗再降至35. 22L,锂电池组循环充电系数进一步降至9. 9/100km,比原单点恒温器控制策略分别降低了9. 9%和50%。

平板电脑充电的技巧

平板电脑充一次电一般只能用几个小时,之后又需充电,平板电脑要如何充电？又如何知道充好电了呢？这是一个必须了解的问题。 如何充电？

增程式电动汽车复合式蓄能系统能量管理策略研究

就增程式电动汽车而言,其蓄能系统配置及能量管理策略对其自身等效燃油经济性、电池组寿命和动力性能有重要作用。本研究描述了本项目开发的搭载超级电容的增程式电动汽车复合式蓄能系统配置,开发了基于模糊逻辑的能量管理策略,并基于Matlab/Simulink仿真分析了二者协同作用下车辆表现的提升与电池组循环寿命的保护。其中,能量管理策略特别关注了加速踏板加速度信息,以更好的理解驾驶员的驾驶意图,进一步优化各蓄能部件及发电部件间的功率分配,起到预判和应对突发功率需求、保护电池组寿命的作用。仿真结果显示,车辆功率响应速度和动力性能得到提高、电池组寿命得到保护。

Cycle life prediction of traction battery based on degradation data

The traction battery cycle life prediction method using performance degradation data was proposed. The example battery was a commercialized lithium-ion cell with LiMn2O4/Graphite cell system. The capacity faded with cycle number follows a traction function path. Two cycle life predicting models were established. The possible cycle life was extrapolated, which follows normal distribution well. The distribution parameters were estimated and the battery reliability was evaluated. The models＇ precision was validated and the effect of the cycle number on the predicting precision was analysed. The cycle life models and reliability evaluation method resolved the difficulty of battery life appraisal, such as long period and high cost.

LiPON固体电解质膜对金属锂电极的保护作用

制备LiPON固体电解质薄膜,通过电沉积手段获得由LiPON膜保护的金属锂电极,测试该电极在有机电解液体系中的电化学性质。结果表明:LiPON膜的存在,抑制了锂电极和电解液之间的非法拉第反应,使锂电极具有更加稳定的电极/电解液界面。由于LiPON膜的保护作用,金属锂电极在充放电循环中也表现出优越的界面稳定性,从而获得更高的库伦循环效率和更好的电池循环寿命。

Research progresses of cathodic hydrogen evolution in advanced lead–acid batteries

Integrating high content carbon into the negative electrodes of advanced lead–acid batteries effectively eliminates the sulfation and improves the cycle life,but brings the problem of hydrogen evolution,which increases inner pressure and accelerates the water loss.In this review,the mechanism of hydrogen evolution reaction in advanced lead–acid batteries,including lead–carbon battery and ultrabattery,is briefly reviewed.The strategies on suppression hydrogen evolution via structure modifications of carbon materials and adding hydrogen evolution inhibitors are summarized as well.The review points out effective ways to inhibit hydrogen evolution and prolong the cycling life of advanced lead–acid battery,especially in high-rate partial-state-of-charge applications.

Flexible three-dimensional-networked iron vanadate nanosheet arrays/carbon cloths as high-performance cathodes for magnesium ion batteries

Owing to their safety and low cost,magnesium ion batteries(MIBs)have attracted much attention in recent years.However,the sluggish diffusion dynamics of magnesium ions hampers the search for appropriate cathode materials with excellent electrochemical performance.Herein,we design and synthesize a novel flexible three-dimensional-networked composite of iron vanadate nanosheet arrays/carbon cloths(3 D FeVO/CC)as a binder-free cathode for MIBs.Relative to bare FeVO nanosheets,the 3 D binder-free electrode with designed architecture enables a full range of electrochemical potential,including a high specific capacity of270 mA h g^(-1) and an increased life span(over 5000 cycles).Such achievable high-density energy originates from the synergistic optimization of electron and ion kinetics,while the durability benefits from the robust structure that prevents degradation in cycling.The single-phase reaction mechanism of FeVO in the magnesium ion storage process is also explored by in-situ X-ray diffraction and Raman technologies.Moreover,a flexible MIB pouch cell(3 D FeVO/CCIMgNaTi_(3)O_(7)) is assembled and exhibits practical application potential.This work verifies that 3 D FeVO/CC is a potential candidate cathode material that can satisfy the requirements of highperformance MIBs.It also opens a new avenue to improve the electrochemical performance of cathode materials for MIBs.

Thiourea-based polyimide/RGO composite cathode:A comprehensive study of storage mechanism with alkali metal ions

Although organic electrode materials have merits of abundant resources,diverse structures and environmental friendliness,their performance for electrochemical energy storage is far insufficient.In this work,a thiourea-based polyimide/reduced graphene oxide(PNTCSA/RGO)composite was synthesized via a condensation polymerization method.As a cathode material in lithium-ion batteries,excellent performance is demonstrated with high reversible capacity(144.2 mA h g^−1),high discharge voltage(∼2.5 V),and long cycling life(over 2000 cycles at 500 mA g^−1),which are comparable to those of other well documented in organic electrodes.Encouraging electrochemical performance is also demonstrated for sodium ion batteries(a cycling life of 800 cycles at 500 mA g^−1),while poor performance is delivered in potassium ion batteries.Theoretical studies reveal that the active sites are carbonyl groups for all alkali ions but one inserted alkali metal ion is shared by two carbonyl groups from the two neighbor units.More importantly,K ions have stronger interaction with S atoms than Li/Na ions,which may lead to poor structure reversibility and account for the poor cycling performance.Our findings provide a fundamental understanding of polyimide based polymer electrodes and help to design and develop high performance organic electrode materials for alkali metal ion batteries.

On-site building of a Zn^(2+)-conductive interfacial layer via short-circuit energization for stable Zn anode

Aqueous zinc ion batteries(ZIBs)show great potential in large-scale energy storage systems for their advantages of high safety,low cost,high capacity,and environmental friendliness.However,the poor performance of Zn metal anode seriously hinders the application of ZIBs.Herein,we use the zinc-ion intercalatable V_(2)O_(5)nH_(2)O(VO)as the interface modification material,for the first time,to on-site build a Zn^(2+)-conductive ZnxV_(2)O_(5)nH_(2)O(ZnVO)interfacial layer via the spontaneous short-circuit reaction between the pre-fabricated VO film and Zn metal foil.Compared with the bare Zn,the ZnVO-coated Zn anode exhibits better electrochemical performances with dendrite-free Zn deposits,lower polarization,higher coulombic efficiency over 99%after long cycles and 10 times higher cycle life,which is confirmed by constructing Zn symmetrical cell and Zn|ZnSO_(4)+Li_(2)SO_(4)|LiFePO_(4) full cell.

SnSe2 nanocrystals coupled with hierarchical porous carbon microspheres for long-life sodium ion battery anode

Tin selenides have been attracting great attention as anode materials for the state-of-the-art rechargeable sodium-ion batteries(SIBs)due to their high theoretical capacity and low cost.However,they deliver unsatisfactory performance in practice,owing to their intrinsically low conductivity,sluggish kinetics and volume expansion during the charge-discharge process.Herein,we demonstrate the synthesis of SnSe2 nanocrystals coupled with hierarchical porous carbon(SnSe2 NCs/C)microspheres for boosting SIBs in terms of capacity,rate ability and durability.The unique structure of SnSe2 NCs/C possesses several advantages,including inhibiting the agglomeration of SnSe2 nanoparticles,relieving the volume expansion,accelerating the diffusion kinetics of electrons/ions,enhancing the contact area between the electrode and electrolyte and improving the structural stability of the composite.As a result,the as-obtained SnSe2 NCs/C microspheres show a high reversible capacity(565 mA h g^-1 after 100 cycles at 100 mA g^-1),excellent rate capability,and long cycling life stability(363 mA h g^-1 at1 A g^-1 after 1000 cycles),which represent the best performances among the reported SIBs based on SnSe2-based anode materials.

Carbon-coating-increased working voltage and energy density towards an advanced Na3V2(PO4)2F3@C cathode in sodium-ion batteries

One main challenge for phosphate cathodes in sodium-ion batteries(SIBs)is to increase the working voltage and energy density to promote its practicability.Herein,an advanced Na3V2(PO4)2F3@C cathode is prepared successfully for sodium-ion full cells.It is revealed that,carbon coating can not only enhance the electronic conductivity and electrode kinetics of Na3V2(PO4)2F3@C and inhibit the growth of particles(i.e.,shorten the Na^+-migration path),but also unexpectedly for the first time adjust the dis-/charging plateaux at different voltage ranges to increase the mean voltage(from 3.59 to 3.71 V)and energy density from 336.0 to 428.5 Wh kg^-1 of phosphate cathode material.As a result,when used as cathode for SIBs,the prepared Na3V2(PO4)2F3@C delivers much improved electrochemical properties in terms of larger specifc capacity(115.9 vs.93.5 mAh g^-1),more outstanding high-rate capability(e.g.,87.3 vs.60.5 mAh g^-1 at 10 C),higher energy density,and better cycling performance,compared to pristine Na3V2(PO4)2F3.Reasons for the enhanced electrochemical properties include ionicity enhancement of lattice induced by carbon coating,improved electrode kinetics and electronic conductivity,and high stability of lattice,which is elucidated clearly through the contrastive characterization and electrochemical studies.Moreover,excellent energy-storage performance in sodium-ion full cells further demonstrate the extremely high possibility of Na3V2(PO4)2F3@C cathode for practical applications.

Cathodic Zn underpotential deposition:an evitable degradation mechanism in aqueous zinc-ion batteries

Aqueous zinc-ion batteries(AZIBs)are promising for large-scale energy storage,but their development is plagued by inadequate cycle life.Here,for the first time,we reveal an unusual phenomenon of cathodic underpotential deposition(UPD)of Zn,which is highly irreversible and considered the origin of the inferior cycling stability of AZIBs.Combining experimental and theoretical simulation approaches,we propose that the UPD process agrees with a two-dimensional nucleation and growth model,following a thermodynamically feasible mechanism.Furthermore,the universality of Zn UPD is identified in systems,including VO_(2)//Zn,TiO_(2)//Zn,and SnO_(2)//Zn.In practice,we propose and successfully implement removing cathodic Zn UPD and substantially mitigate the degradation of the battery by controlling the end-ofdischarge voltage.This work provides new insights into AZIBs degradation and brings the cathodic UPD behavior of rechargeable batteries into the limelight.

Carbon-coated Fe2O3 hollow sea urchin nanostructures as high-performance anode materials for lithium-ion battery

Fe2O3 has become a promising anode material in lithium-ion batteries (LIBs) in light of its low cost, high theoretical capacity (1007 mA h g^−1) and abundant reserves on the earth. Nevertheless, the practical application of Fe2O3 as the anode material in LIBs is greatly hindered by several severe issues, such as drastic capacity falloff, short cyclic life and huge volume change during the charge/discharge process. To tackle these limitations, carbon-coated Fe2O3 (Fe2O3@MOFC) composites with a hollow sea urchin nanostructure were prepared by an effective and controllable morphology-inherited strategy. Metal-organic framework (MOF)-coated FeOOH (FeOOH@-MIL-100(Fe)) was applied as the precursor and self-sacrificial template. During annealing, the outer MOF layer protected the structure of inner Fe2O3 from collapsing and converted to a carbon coating layer in situ. When applied as anode materials in LIBs, Fe2O3@MOFC composites showed an initial discharge capacity of 1366.9 mA h g^−1 and a capacity preservation of 1551.3 mA h g^−1 after 200 cycles at a current density of 0.1 A g^−1. When increasing the current density to 1 A g^−1, a reversible and high capacity of 1208.6 mA h g^−1 was obtained. The enhanced electrochemical performance was attributed to the MOF-derived carbon coating layers and the unique hollow sea urchin nanostructures. They mitigated the effects of volume expansion, increased the lithium-ion mobility of electrode, and stabilized the as-formed solid electrolyte interphase films.