High performance cathode materials for lithium-ion batteries based on a phenothiazine-based covalent triazine framework

Abstract

As a novel class of robust redox-active organic polymers, covalent triazine frameworks (CTFs) are highly promising cathode materials for lithium-ion batteries. However, the low electronic conductivity, low redox potentials, and...

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

“…Enhanced rate performance can be achieved by preparation compounds with high conductivity or by combining nitrogen-centered materials with highly conductive substances, such as graphene and carbon nanotubes (CNTs). [58,59] On the other hand, the high solubility of nitrogen-centered compounds causes continuous loss of active materials and rapid capacity decay during cycling. Four effective strategies are proposed to suppress the dissolution of nitrogen-centered materials: 1) polymerization, which involves creating polymerized nitrogen-redox-center compounds to increase molecular weight and mitigate dissolution issues of smaller structures; [60] 2) salification, wherein compounds (e.g., COOM, M = Li, Na, K) with high polarity exhibit low solubility in aprotic electrolytes; [52] 3) hybridization with insoluble species, for instance, Lin et al reported that the poly(2,2,6,6-tetramethylpiperidin-1-oxyl-4ylmethacrylate) (PTMA) brushed on silica nanoparticles delivered a better cycling performance (96.3% capacity retention after 300 cycles) compared to the PTMA composite cathodes (81.9% capacity retention at the same conditions) for the reduced dissolution of PTMA active material; [61] (4) electrolyte optimization.…”