A lattice-matched interface between in situ/artificial SEIs inhibiting SEI decomposition for enhanced lithium storage

Abstract

Due to the continuous decomposition of the in situ solid-electrolyte interphase (SEI) between the electrolyte and anodes such as Li metal, Si, MoS₂, etc., the low cycling stability has become one of the challenges for practical application of new-type Li-ion batteries (LIBs) with high energy density. Herein, an artificial LiAlO₂ SEI is inserted between the in situ SEI and anode to improve the cycling stability of the batteries, through the formation of lattice-matched interfaces between the artificial LiAlO₂ and in situ formed SEI components such as LiF, Li₂CO₃, LiPO₂F₂, etc. The lattice-matched interfaces can efficiently suppress mechanical and chemical degradation and retain the in situ SEI and consequently the cell stability through cycling. Taking a conversion-type Ni₃S₂ electrode as a model system, the stabilization mechanism of the in situ SEI is well illustrated and the reversible capacity attenuation of Ni₃S₂ from the 2^nd to 100^th cycle can be significantly reduced from 35.8% to 1.2%, in the presence of the lattice-matched interfaces. The proposed strategy is highly effective and inspiring to solve the challenge of in situ SEI decomposition and achieve a stable cycling in LIBs with different electrodes.