介孔碳材料抑制锂电池负极枝晶生长

为了解决锂电池负极表面锂枝晶生长带来的性能衰退和安全问题。 以沸石咪唑酯骨架-8(ZIF-8)为前驱体制得介孔碳材料(MCM),用于金属锂负极表面改性。 X射线粉末衍射(XRD)和拉曼光谱表明,退火制得的MCM具有一定的石墨化程度,N₂气吸脱附测试(BET)证明MCM具有典型的介孔特征。 对比不同温度退火样品的XRD、拉曼光谱和BET测试结果,确定900 ℃为最佳退火温度。 优化的MCM作为表面改性剂对金属锂负极进行改性研究。 电池充放电循环后,负极样品的XRD和扫描电子显微镜(SEM)测试表明,MCM能够通过均衡锂负极表面的电荷分布抑制金属锂的取向沉积和锂枝晶的生长。 本研究为制备抑制锂电池负极枝晶生长表面改性剂提供了一种简便而有效的合成方法,有利于锂电池循环寿命的延长和安全性能的提高。

Mesoporous Carbon Matrix Suppressing Dendritic Growth of Lithium Battery Anode

To avoid the performance fading and safety problem of lithium batteries caused by dendrite growth on the surface of lithium anode, the mesoporous carbon matrix (MCM) was prepared using the zeolitic imidazolate framework-8 (ZIF-8) as the template and precursor. X-ray powder diffraction (XRD) and Raman spectroscopy indicate that the MCM has a certain degree of graphitization, and the N₂ adsorption-desorption test (BET) proves that MCM has typical mesoporous characteristics. The XRD, Raman and BET test results suggest that the optimum annealing temperature is 900 ℃. The optimized MCM is used to study the surface modification of lithium anode. After the charge and discharge cycle test, the XRD and scanning electron microscopy (SEM) tests show that the orientation deposition of lithium metal is avoided and the growth of lithium dendrites is suppressed because MCM can balance the charge distribution on the lithium anode surface. This work reveals a facile but efficient synthesis approach of the surface modification agent to extend the cycle life and enhance the safety for high performance lithium batteries.