PEDOT:PSS @Molecular Sieve as Dual‐Functional Additive to Enhance Electrochemical Performance and Stability of Ni‐Rich NMC Lithium‐Ion Batteries

Abstract

Molecular sieves (MSs) coated with conductive polymer (PEDOT:PSS) are used as water scavengers to modify the nickel‐rich LiNi1–x–yCoxMnyO2 (NMC)‐layered cathode. This strategy proactively captures residual water in the battery system without affecting the transport performance of electrons and Li+ ions. The moisture content and nuclear magnetic resonance (NMR) tests show that MSs after coating still maintain good water absorption characteristics and inhibit the decomposition of the electrolyte. The conductivity of the PEDOT:PSS@MS‐NMC electrode is 1.08 × 10−4 S cm−1, which is improved by 63.9%, compared with the MS‐NMC electrode. Through X‐ray photoelectron spectroscopy, transmission electron microscopy, and scanning electron microscopy measurements, it is also shown that the surface structure stability and particle integrity for PEDOT:PSS@MS‐NMC electrode is well retained. After 500 cycles, the capacity retention of the composite cathode is 71.3%, which is higher than that of the NMC (38.3%) and MS‐NMC cathode (62.4%). This is a novel and effective strategy to suppress side reactions at the electrode interface and improve electrode stability, capacity retention, and cycle performance of the Ni‐rich NMC cathode.