Title : Advanced non-woven separator membrane by syringeless electrospinning for high-performance lithium-ion energy device
Separators play a critical role in determining the electrochemical performance and safety of lithium-ion batteries (LIBs). Developing separators to meet the various requirements of next-generation LIBs is quite challenging because it is extremely difficult to simultaneously meet safety issues and high performance, resulting in a technical contradiction. In general, an electrospun nonwoven membrane is one of the promising candidates for next-generation LIBs separators, but sufficiently thin electrospun-based nonwoven webs cannot be commercialized as separators due to their poor mechanical strength and excessively large porosity, which fail to withstand dendrite growth. In order to overcome these shortcomings, we used a syringeless colloidal electrospinning method to fabricate a composite nonwoven separator using polyvinylidene fluoride (PVDF) and lithium lanthanum zirconium oxide (Li6.4La3Zr2Al0.2O12, LLZO) particles. By evaluating the electrochemical performance of cells assembled with NCM622/graphite at a high C-rate, we have successfully demonstrated the feasibility of our separator membrane for use in high-power and high-energy LIBs. The assembled cell containing our separator membrane exhibited an outstanding specific capacity of 115 mAh?g-1 with 97 % capacity retention after 100 cycles, even at 3 C. Additionally, a lithium metal cell with our PVDF/LLZO separator showed improved stable cycle life and achieved capacity retention of 86 % after 250 cycles at 0.5 C.
Audience Take Away:
- The syringeless electrospinning method enables mass production at a fast production speed and is cost-effective
- The syringeless electrospinning method can produce multifunctional separators by applying various polymer materials and additives, which enables research on next-generation batteries
- Syringeless electrospinning, a new process in which multiple probe rods simultaneously compose nanofibers, can overcome the limitations of conventional electrospinning with a single needle