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锂离子电池内部结构是一种复杂的分布参数系统, 如果为了降低计算难度而使用常微分方程描述锂离子电池, 可能会引入系统误差, 降低系统模型的可信度, 需要使用偏微分方程建立分布参数系统的精确模型. 本文提出了一种基于单粒子模型和抛物型偏微分方程的锂离子电池系统建模与故障监测系统设计方法, 当锂离子浓度实测值与理想值的残差大于预设门槛时判定分布参数系统处于故障状态. 通过一个仿真实例进行了锂离子电池系统建模和故障诊断实验, 实验证明基于单粒子模型和偏微分方程的锂离子电池故障监测系统具有更高的精确度和可信度. 相似文献
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提出了一种基于分布参数系统偏微分方程描述和单粒子模型的锂离子电池工作状态实时监控建模方法,能够实时跟踪锂离子电池阳极的锂离子密度和残差变化,并通过仿真实验验证了本文模型对锂离子电池工作状态故障报警的有效性和精确性. 相似文献
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锂离子电池是一种较为复杂的电化学系统, 其涵盖质量传递、电荷传递、热量传递以及多种电化学反应等物理化学过程. 其不仅物理尺度跨越大, 从微观活性颗粒、极片、电芯跨越到电池模组, 还面临着成组配对以及均衡性的问题, 这些问题加剧了电池设计和性能综合评估的难度. 通过计算机数值仿真技术, 建立数学模型, 全面和系统地捕捉电池工作过程各物理场的相互作用机理, 分析其演化规律, 能够为优化电池系统设计提供理论支撑. 本文对锂离子电池的数值模型研究进展和发展趋势进行了综述. 同时对主要理论模型进行了分类整理, 总结了它们的特点、适用范围和局限性, 指出了将来进一步研究的方向和难点所在, 这些对锂离子电池多尺度数值模型的理论研究和工程应用都具有指导性的意义. 相似文献
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Lithium nitrate (LiNO3) is reported as an effective additive to protect lithium anode in rechargeable lithium-sulfur battery. However, for its strong oxidation, cells containing LiNO3 still suffer from safety problems and poor cycle performance since LiNO3 can be reduced on cathode to form some irreversible products. In this study, a facile and effective method to pre-passivate lithium anode is proposed by simply immersing lithium plates in LiNO3 solution. The electrochemical properties show that the pretreatment is favorable for the construction of a protection layer on the surface of lithium anode. Cells with pretreated lithium show the coulombic efficiency of 80.6 % in the first cycle and 87.2 % after 100 cycles, far higher than the one with pure lithium. The discharge capacity is retained at 702 mA h g?1 after 100 cycles, and the result is better than those directly adding LiNO3 in electrolyte. It is believed that these improvements result from the high stability of surface film during the charge and discharge process, which can stabilize the structure of anode and suppress the shuttle effect. 相似文献
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In this work we report a lithium ion battery based on a nanostructured Sn-C anode, an improved lithium iron phosphate, LiFePO4, cathode and a polyethylene oxide-based electrolyte. The battery has a solid-like configuration, high safety and can operate at room temperature with a stable capacity of the order of 120 mAh g− 1 at a voltage of 2.8 V. These properties candidate the battery as very appealing energy accumulation system suitable for environmentally friendly, safe, applications. 相似文献
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硅功能化石墨烯(硅化烯)作为锂离子电池的负极材料, 一旦发生分层或粉化等损伤现象, 会严重地降低材料的电子输运能力和储锂容量, 减少电池的使用寿命, 因此要求负极材料具有较强的力学可靠性. 考虑到传统分子动力学方法的模拟尺度很难达到硅化烯负极材料的真实尺度, 首先采用Tersoff 势函数和Lennard-Jones 势函数建立了多种硅化烯的全原子数值模型, 计算材料的各种弹性模量和吸附能; 然后采用珠子-弹簧结构, 根据力学平衡条件和能量守恒定律, 结合全原子模型的计算结果, 建立了硅化烯粗粒模型及其系统的能量方程; 最后, 通过对比石墨烯粗粒模型与其全原子模型的拉伸性能, 验证了硅化烯粗粒模型的有效性. 相似文献
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Chromium thio-phosphate, CrPS4, has a layered structure based on hexagonally close packed sulfur layers. Magnetic susceptibility measurements indicated an antiferromagnetic ordering perpendicular to the C axis and the presence of trivalent chromium in the paramagnetic region. Optical transmission spectra showed the fundamental absorption edge to occur at 2.4 eV. Using n-butyl lithium techniques, it was found that CrPS4 can readily accomodate lithium. This insertion is not allowed by any parameter change in the host structure nor reduction of the Cr3+ magnetic moment. Lithium NMR measurements gave a rather high (0.31 eV) energy of activation for lithium movement and use of CrPS4 as a cathode against a lithium anode showed a sharp drop in potential. 相似文献
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Three morphologies of two-dimension Boron with metallicity have been successfully synthetized by experiments. To access the potential of β12 borophene (□) and χ3 borophene monolayer (◇) as anode materials for lithium ion batteries, first-principles calculations based on density functional theory (DFT) are performed. Lithium atom is preferentially absorbed over the center of the hexagonal B atom hollow of β12 and χ3 borophene monolayer. The fully lithium storage phase of β12 and χ3 borophene monolayer corresponds to Li8B10 and Li8B16 with a theoretical specific capacity of 1983 and 1240 mA h g?1, respectively, much larger than other two-dimension materials. Interestingly, lithium ion diffusion on β12 borophene (□) monolayer is extremely fast with a low-energy barrier of 41 meV. Meanwhile, lithiated-borophene monolayer shows enhanced metallic conductivity during the whole lithiation process. Compared to the buckled borophene (△), the extremely enhanced lithium adsorption energy of β12 and χ3 phase with vacancies weakens lithium ion diffusion. Therefore, it is important to control the generation of vacancy in the buckled borophene (△) anode for lithium ion batteries. Borophene is a promising candidate with high capacity and high rate capability for anode material in lithium ion batteries. 相似文献