A Polyacrylonitrile Shutdown Film for Prevention of Thermal Runaway in Lithium-Ion Cells
A Polyacrylonitrile Shutdown Film for Prevention of Thermal Runaway in Lithium-Ion Cells
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DOI：
10.3390/batteries9050282
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发表时间：
2023-05
期刊：
影响因子：
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通讯作者：
Jonathan Allen;Marcin Mierzwa;D. Kramer;N. García-Aráez;A. Hector
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作者：
Jonathan Allen;Marcin Mierzwa;D. Kramer;N. García-Aráez;A. Hector
电沉积聚合物（聚丙烯腈，PAN）用于降低锂离子电池热失控的风险，而热失控是电池事故和火灾的最重要原因。在以丙烯腈为溶剂的溶液中，采用循环伏安法或计时安培法将PAN电沉积在石墨电池电极上。通过拉曼光谱、显微镜、能量色散x射线分析和热重分析对电沉积PAN薄膜进行了表征，发现薄膜厚度可以通过电化学实验中通过的电荷量来控制。然后在锂半电池中测试pan涂层石墨电池电极，获得接近未涂层石墨样品的容量（约360 mA h g−1），薄（20µm），发现当温度超过80°C时，容量急剧下降。由于与电极接触的电解质降解的电化学反应是热失控过程的根本原因，因此这种抑制容量可用于热失控保护。进一步的工作应该研究替代聚合物和液体电解质配方，以实现在高温下抑制电化学容量的期望，同时在工作温度范围内保持高容量。
The electrodeposition of a polymer (polyacrylonitrile, PAN) is used to reduce the risk of thermal runaway in lithium-ion batteries, which is the most important cause of battery accidents and fires. PAN was electrodeposited on a graphite battery electrode, using cyclic voltammetry or chronoamperometry, in a solution with acrylonitrile as the solvent. The electrodeposited PAN film was characterised by Raman spectroscopy, microscopy, energy dispersive X-ray analysis, and thermogravimetric analysis, and it was found that the film thickness could be controlled by the amount of charge passed in the electrochemical experiments. The PAN-coated graphite battery electrode was then tested in lithium half-cells, obtaining capacities close to the uncoated graphite sample (ca. 360 mA h g−1) for thin (20 µm) it was found that the capacity decreased drastically as the temperature increased beyond 80 °C. Such suppression in capacity has applications for thermal runaway protection since the electrochemical reactions of degradation of the electrolyte in contact with the electrode are the root cause of the thermal runaway process. Further work should look into alternative polymer and liquid electrolyte formulations to achieve the desired suppression of electrochemical capacity at high temperatures while retaining high capacities at the operational temperature range.