高電圧リチウム金属電池用リチウムアノード上の階層的人工固体電解質界面層によるサイクリング安定性の向上とリチウムデンドライト形成の抑制

Lithium metal anodes are promising for next-generation high-energy batteries owing to a high theoretical capacity and low redox potential. However, their use is limited due to uncontrolled dendrite growth, unstable solid electrolyte interphase (SEI), and poor cycling stability. This article reports a new thin layer composed of organic and inorganic materials, specifically combining hexafluorocyclotriphosphazene (HFPN) and Al₂O₃ nanoparticles along with a poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) copolymer binder. This layer is applied to Li metal anodes using a spin coating method to create a HFPN@Al₂O₃ artificial SEI (ASEI) layer (HAPH@Li). HAPH@Li benefits from the strength of Al₂O₃ and ionic conductivity of PVDF-HFP. The HFPN additive, rich in F, N, and P, assisted in the formation of a stable SEI to effectively control the flow of Li ions and reduce Li dendrite formation. Moreover, full cells assembled using HAPH@Li anodes paired with Ni-rich NCMA90 cathodes operated at 2.8-4.3 V. The NCMA/HAPH_0.5:1@Li full cell outperformed other full cells with bare and other ASEI-modified Li anodes. The full cell achieved a high Coulombic efficiency of > 99.62%, initial discharge capacity of 181.9 mAh g^-1, and capacity retention exceeding 75.7% over 300 cycles at 1C/1C.