Ordered lithium-ion channel in carbonyl-rich conjugated microporous polymer composite solid electrolytes for stable lithium batteries

The development of rapid and stable ionic conduction pathways is imperative for solid-state electrolytes to fulfil their role in achieving high-performance lithium metal batteries. In this study, a novel anthraquinone-based conjugated microporous polymer (PTAQ) was successfully designed and synthesized, and incorporated as a functional filler with polyacrylonitrile (PAN) to prepare a high-performance Li + -PTAQ-PAN composite polymer solid-state electrolyte. The successful synthesis of PTAQ was confirmed by FTIR, NMR, and XPS. Research indicates that the electron-rich carbonyl groups in PTAQ serve as effective lithium-ion binding sites, and DFT calculations demonstrated their ability to significantly promote lithium salt dissociation and establish fast and ordered lithium-ion transport pathways. The resulting 15 wt%Li + -PTAQ-PAN electrolyte exhibits high ionic conductivity (3.36 × 10 −4 S cm −1 at 25 °C), a high lithium-ion transference number (0.68), and a wide electrochemical window (5.4 V) at room temperature. The formation of a LiF-rich solid electrolyte interphase facilitates uniform lithium deposition, which enables the Li + -PTAQ-PAN solid-state electrolyte to function reliably for over 2000 h at 0.025 mA cm −2 . Furthermore, this stability translates to outstanding electrochemical performance in full cells, as evidenced by Li||LiFePO 4 batteries maintaining a high specific capacity of 190.9 mAh g −1 after 800 cycles at 0.5 C and exhibiting remarkable rate capability. This work provides a new material design and strategy for developing safe and high-performance solid-state lithium batteries. • A novel carbonyl-rich CMP (PTAQ) is synthesized as a filler for composite solid electrolytes. • The carbonyl in PTAQ promotes lithium salt dissociation and fast Li⁺ transport. • The 15 wt% Li⁺-PTAQ-PAN electrolyte shows high conductivity (3.36×10⁻⁴ S cm⁻¹) and wide electrochemical window (5.4 V). • A rich LiF interphase enables stable Li deposition and over 2000 h stable cycling in symmetric Li batteries.