AI 中文总结
本研究通过半电池开路电位数据对商用NCA正极进行多物种多反应（MSMR）模型参数化，发现NCA正极热力学特征在老化中基本不变，支持固定电极固有参数、将老化归因于电极层面变化的建模方法。
AI 中文摘要
锂离子电池的物理基模型需要每个电极的开路电位（OCP）作为其嵌锂量的函数。多物种多反应（MSMR）模型提供了这种关系的紧凑、热力学基础的描述，用标准电位、位点分数和无序参数表示每个嵌入反应。本研究针对汽车电池中广泛使用的正极化学物质镍钴铝氧化物（NCA），利用商用硅-石墨/NCA电池的正极对MSMR模型进行参数化。从全新电池以及在两种荷电状态窗口下循环老化至寿命终点的电池中提取正极材料，通过慢速恒电流循环测量其半电池OCP。通过直方图计数获得平滑的微分容量曲线，并采用受约束的、尺度不变的优化方法拟合充放电分支，使每个反应都锚定在可见峰上。本研究报告了首个NCA正极的MSMR参数集，并通过跨老化状态的微分容量峰分析表明，其热力学特征在老化过程中基本保持不变。这一发现支持了常见的建模实践，即固定电极的固有参数，将老化归因于电极层面的容量和对齐变化。
英文摘要
Physics-based models of lithium-ion batteries require the open-circuit potential (OCP) of each electrode as a function of its lithiation. The multi-species multi-reaction (MSMR) model provides a compact, thermodynamically grounded description of this relationship, representing each insertion reaction by a standard potential, a site fraction and a disorder parameter. Here, we parametrize the MSMR model for nickel-cobalt-aluminum oxide (NCA), a cathode chemistry widespread in automotive cells, using the positive electrode of a commercial silicon-graphite/NCA cell. Cathode material was harvested from a pristine cell and from cells cycle-aged to the end of life under two state-of-charge windows, and its half-cell OCP was measured by slow galvanostatic cycling. Smooth differential-capacity curves were obtained by histogram counting, and the charge and discharge branches were fitted with a constrained, scale-invariant optimization that keeps every reaction anchored to a visible peak. We report the first MSMR parameter set for an NCA cathode and show, through a differential-capacity peak analysis across aging states, that its thermodynamic signature is essentially unchanged by aging. This finding supports the common modeling practice of holding the electrode's intrinsic parameters fixed and ascribing aging to electrode-level capacity and alignment changes.
Comments21 pages, 7 figures, 3 tables
