未来电动汽车电池金属锂隔离膜研究

Study on Lithium Metal Isolation Membrane for Future Electric Vehicle Batteries

金属锂(Li)作为负极在可充电金属锂电池中的直接应用仍存在一些问题,如锂枝晶的形成、库仑效率低和安全隐患等。为了稳定锂阳极,在商用12μm聚乙烯隔膜上采用叶片式涂覆轻质薄功能层的方法制备了一种先进的复合隔膜。该复合分离器同时改善了锂离子的迁移和锂离子沉积行为,使锂离子分布均匀,实现了无枝晶锂沉积。因此,锂阳极可以稳定循环长达3000次,容量高达3.5 mAh/cm^(2)。此外,复合隔膜在lmb(Li-S和Li-ion电池)中具有广泛的兼容性,在硬币级和实验室级软包电池中都具有稳定的循环性能和高库仑效率。

There are still some problems in the direct application of lithium metal(Li)as anode in rechargeable lithium metal battery,such as the formation of lithium dendrite,low coulomb efficiency and potential safety hazards.In order to stabilize the lithium anode,an advanced composite diaphragm has been prepared by laminating a lightweight,thin functional layer on a commercial 12μm polyethylene diaphragm.The composite separator improves the lithium ion migration and lithium ion deposition behavior at the same time,so that the lithium ion distribution is uniform and dendrite-free lithium deposition is realized.As a result,the lithium anode can be stably cycled up to 3000 times and has a capacity of up to 3.5mah cm 2.In addition,the composite diaphragm has wide compatibility in LMB(Li-S and Li-ion cells),stable cycle performance and high Coulomb efficiency in both coin-grade and laboratory-grade soft-pack cells.