Optimization of Monomer Molecular Structure for Polymer Electrodes Fabricated through in-situ Electro-Polymerization Strategy

Versatile Nitrogen-Centered Organic Redox-Active Materials for Alkali Metal-Ion Batteries

Versatile nitrogen-centered organic redox-active molecules have gained significant attention in alkali metal-ion batteries (AMIBs) due to their low cost, low toxicity, and ease of preparation. Specially, their multiple reaction categories (anion/cation insertion types of reaction) and higher operating voltage, when compared to traditional conjugated carbonyl materials, underscore their promising prospects. However, the high solubility of nitrogen-centered redox active materials in organic electrolyte and their low electronic conductivity contribute to inferior cycling performance, sluggish reaction kinetics, and limited rate capability. This review provides a detailed overview of nitrogen-centered redox-active materials, encompassing their redox chemistry, solutions to overcome shortcomings, characterization of charge storage mechanisms, and recent progress. Additionally, prospects and directions are proposed for future investigations. It is anticipated that this review will stimulate further exploration of underlying mechanisms and interface chemistry through in situ characterization techniques, thereby promoting the practical application of nitrogen-centered redox-active materials in AMIBs.

High-Performance Poly(1-naphthylamine)/Mesoporous Carbon Cathode for Lithium-Ion Batteries with Ultralong Cycle Life of 45000 Cycles at -15 °C

Organic electrode materials for lithium-ion batteries have attracted significant attention in recent years. Polymer electrode materials, as compared to small-molecule electrode materials, have the advantage of poor solubility, which is beneficial for achieving high cycling stability. However, the severe entanglement of polymer chains often leads to difficulties in preparing nanostructured polymer electrodes, which is vital for achieving fast reaction kinetics and high utilization of active sites. This study demonstrates that these problems can be solved by the in situ electropolymerization of electrochemically active monomers in nanopores of ordered mesoporous carbon (CMK-3), combining the advantages of the nano-dispersion and nano-confinement effects of CMK-3 and the insolubility of the polymer materials. The as-prepared nanostructured poly(1-naphthylamine)/CMK-3 cathode exhibits a high active site utilization of 93.7%, ultrafast rate capability of 60 A g-1 (≈320 C), and an ultralong cycle life of 10000 cycles at room temperature and 45000 cycles at -15 °C. The study herein provides a facile and effective method that can simultaneously solve both the dissolution problem of small-molecule electrode materials and the inhomogeneous dispersion issue of polymer electrode materials.