Bai Wei, Xiao Lei, Long Tao, Wang Zhirong, Wang Junling, Richard Yuen Kwok Kit, Lu Yawei
Jiangsu Key Laboratory of Hazardous Chemicals Safety and Control, College of Safety Science and Engineering, Nanjing Tech University, Nanjing 211816, China.
Jiangsu Key Laboratory of Hazardous Chemicals Safety and Control, College of Safety Science and Engineering, Nanjing Tech University, Nanjing 211816, China.
J Colloid Interface Sci. 2025 Apr 15;684(Pt 1):377-387. doi: 10.1016/j.jcis.2024.12.229. Epub 2024 Dec 30.
Lithium-ion batteries (LIBs) have broad application prospects in many fields because of their high energy density. However, the poor heat resistance of polyolefin membranes and uneven lithium deposition result in battery failure and even infamous thermal runaway behavior. To improve the intrinsic safety of batteries, fire-retardant, thermally conductive, electrospinning strategies are employed to acquire a functional polyacrylonitrile (PAN) nanofiber separator (PAN@FBN/TPP) containing modified boron nitride (FBN) and triphenyl phosphate (TPP). Compared with those of the Celgard separator, the porosity, contact angle, and electrolyte uptake of the Celgard separator are greatly improved. Moreover, the designed separator shows excellent thermal stability without shrinkage when heated at 220 °C. The char residue at 800 °C is 43.7 wt%, which is much greater than that of the Celgard separator (∼0.26 wt%). The maximal peak heat release rate (PHRR) is only 30 % that of the Celgard separator. The improvement in heat resistance laid a solid foundation for the preparation of high-safety LIBs. The advantages of a uniform pore size distribution and extremely high porosity provide abundant active sites and convenient channels for Li migration. The cell with the PAN@FBN/TPP separator shows excellent cycle stability and rate performance. Owing to the high heat resistance of PAN and the excellent flame-retardant capability of FBN, the LIBs presented the highest self-heating temperature (T) and thermal runaway temperature (T) and the smallest maximum temperature (T) and heat release rate (HRR) in the safety performance test; compared with those of commercial separator batteries, the above thermal safety parameters increased by 16.9 %, 6.5 %, 21.8 % and 81.5 %, respectively. Overall, this work may provide an effective way to fabricate LIBs with high thermal safety.
锂离子电池（LIBs）因其高能量密度在许多领域具有广阔的应用前景。然而，聚烯烃膜耐热性差以及锂沉积不均匀会导致电池失效，甚至引发臭名昭著的热失控行为。为提高电池的本质安全性，采用阻燃、导热的静电纺丝策略来制备一种含有改性氮化硼（FBN）和磷酸三苯酯（TPP）的功能性聚丙烯腈（PAN）纳米纤维隔膜（PAN@FBN/TPP）。与Celgard隔膜相比，Celgard隔膜的孔隙率、接触角和电解液吸收率都有显著提高。此外，所设计的隔膜在220℃加热时表现出优异的热稳定性，无收缩现象。800℃时的残炭率为43.7 wt%，远高于Celgard隔膜（约0.26 wt%）。最大热释放速率（PHRR）仅为Celgard隔膜的30%。耐热性的提高为制备高安全性锂离子电池奠定了坚实基础。孔径分布均匀和极高孔隙率的优势为锂迁移提供了丰富的活性位点和便捷通道。采用PAN@FBN/TPP隔膜的电池表现出优异的循环稳定性和倍率性能。由于PAN的高耐热性和FBN出色的阻燃能力，在安全性能测试中，该锂离子电池呈现出最高的自热温度（T）和热失控温度（T），以及最小的最高温度（T）和热释放速率（HRR）；与商业隔膜电池相比，上述热安全参数分别提高了16.9%、6.5%、21.8%和81.5%。总体而言，这项工作可能为制造具有高热安全性的锂离子电池提供一种有效方法。
