Key Words:HEXAGONAL BORON-NITRIDE; ION BATTERIES; ANODE; EXFOLIATION; DEPOSITION; NANOTUBES

Abstract:Battery separator is considered as an important component to avoid direct contact between cathode and anode. The development of separators with high mechanical properties and excellent thermal stability remains a key challenge. Here, free-standing hydroxylated boron nitride nanosheet (OH-BNNS)/aramid nanofiber (ANF) nanocomposite separators with nacre-like structure were prepared by combining high modulus ANF with OH-BNNS through sol-gel conversion process. The OH-BNNS/ANF separator with 20 wt% OH-BNNS loading offers benefits of excellent mechanical properties (strength: 114.86 /- 3.47 MPa, modulus: 3.66 /- 0.29 GPa), high decomposition temperature (507.8 degrees C) as well as better electrolyte wettability (contact angle <5 degrees) compared with commercial polypropylene (PP) separator. A layered structure formed by the overlapped OH-BNNS and ANF contributes to constructing uniform lithium-ion transport channels and suppressing the growth of lithium dendrites. Meanwhile, even under the aging condition of 120 degrees C, the battery with 20 wt% OH-BNNS/ANF separator still maintains stable electrochemical performance and shows high thermal stability. As expected, the Li/lithium titanate (Li/LTO) battery using 20 wt% OH-BNNS/ANF as the separator achieves a capacity of 172.7 mAh g(-1) with a high discharge capacity retention of 96.5 % after 500 cycles, revealing the long-term cycle stability.

Volume:992

Issue:-

Translation or Not:no