Exploring Different Binders for a LiFePO4 Battery, Battery Testing, Modeling and Simulations
Exploring Different Binders for a LiFePO4 Battery, Battery Testing, Modeling and Simulations
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DOI：
10.3390/en15072332
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发表时间：
2022-04-01
期刊：
影响因子：
3.2
通讯作者：
Watts, John F.
中科院分区：
文献类型：
--
作者：
Baboo, Joseph Paul;Yatoo, Mudasir A.;Watts, John F.
本文重点介绍了LiFePO 4（LFP）电池，这是一种经典的、最安全的锂离子电池技术之一。为了促进和使阴极制造更可持续，研究了两种Kynar（R）粘合剂（Arkema，France），其可溶于沸点比传统PVDF粘合剂的常用溶剂低的溶剂中。制备Li-LFP和石墨-Li半电池以及石墨-LFP全电池，并在电化学阻抗谱、循环伏安法（CV）和恒电流充放电循环中进行测试。对于具有三种研究的粘合剂和石墨阳极的LFP电极，采用Rendles-Shevchik方程，从CV图确定扩散系数，并用作基于单颗粒模型的模拟中的输入数据。在LFP阴极上进行微结构和表面组成表征，预循环和25次循环后，揭示了SEI形成、活性锂损失、表面开裂和碎裂的老化效应。在电池循环的模拟中，将单粒子模型与等效电路模型进行比较，得出的结论是，通过基于电池循环的历史数据容易地调整作为循环次数的函数的一些模型参数，后者更准确地预测“未来”循环和LFP电池的寿命。
This paper focuses on the LiFePO4 (LFP) battery, a classical and one of the safest Li-ion battery technologies. To facilitate and make the cathode manufacture more sustainable, two Kynar (R) binders (Arkema, France) are investigated which are soluble in solvents with lower boiling points than the usual solvent for the classical PVDF binder. Li-LFP and graphite-Li half cells and graphite-LFP full cells are fabricated and tested in electrochemical impedance spectroscopy, cyclic voltammetry (CV) and galvanostatic charge-discharge cycling. The diffusion coefficients are determined from the CV plots, employing the Rendles-Shevchik equation, for the LFP electrodes with the three investigated binders and the graphite anode, and used as input data in simulations based on the single-particle model. Microstructural and surface composition characterization is performed on the LFP cathodes, pre-cycling and after 25 cycles, revealing the aging effects of SEI formation, loss of active lithium, surface cracking and fragmentation. In simulations of battery cycling, the single particle model is compared with an equivalent circuit model, concluding that the latter is more accurate to predict "future" cycles and the lifetime of the LFP battery by easily adjusting some of the model parameters as a function of the number of cycles on the basis of historical data of cell cycling.