Building Polymeric Framework Layer for Stable Solid Electrolyte Interphase on Natural Graphite Anode.

The overall electrochemical performance of natural graphite is intimately associated with the solid electrolyte interphase (SEI) layer developed on its surface. To suppress the interfacial electrolyte decomposition reactions and the high irreversible capacity loss relating to the SEI formation on a natural graphite (NG) surface, we propose a new design of the artificial SEI by the functional molecular cross-linking framework layer, which was synthesized by grafting acrylic acid (AA) and N,N'-methylenebisacrylamide (MBAA) via an in situ polymerization reaction. The functional polymeric framework constructs a robust covalent bonding onto the NG surface with -COOH and facilitates Li+ conduction owing to the effect of the -CONH group, contributing to forming an SEI layer of excellent stability, flexibility, and compactness. From all the benefits, the initial coulombic efficiency, rate performance, and cycling performance of the graphite anode are remarkably improved. In addition, the full cell using the LiNi0.5Co0.2Mn0.3O2 cathode against the modified NG anode exhibits much-prolonged cycle life with a capacity retention of 82.75% after 500 cycles, significantly higher than the cell using the pristine NG anode. The mechanisms relating to the artificial SEI growth on the graphite surface were analyzed. This strategy provides an efficient and feasible approach to the surface optimization for the NG anode in LIBs.

Liquid-Phase Condensation via Macromolecular Crowding in Polymerization-Induced Electrostatic Self-Assembly.

Macromolecular crowding plays a key role in liquid-phase condensation of proteins and membraneless organelles yet is largely unexplored for artificial liquid materials. Herein, we present a strategy for direct access to multiphase liquid condensates with individual charged/neutral subdomains, by introducing macromolecular crowding to our previous protocol of liquid-liquid phase-separation-driven polymerization-induced electrostatic self-assembly (LLPS-PIESA). We show that reversible addition fragmentation chain transfer (RAFT) aqueous dispersion photo-copolymerization of a charged monomer with a specific neutral monomer, in the presence of a polar macrochain transfer agent (CTA) and an oppositely charged polyion, can induce self-sorting and macromolecular crowding. LLPS-PIESA proceeds via liquid-phase condensation of as-assembled nascent clusters up to biologically important nanostructured multiphase condensates with individual charged/neutral subdomains.

Polymerization-Induced Hierarchical Electrostatic Self-Assembly: Scalable Synthesis of Multicompartment Polyion Complex Micelles and Their Monolayer Colloidal Nanosheets and Nanocages.

Scalable synthesis of multicompartment polyion complex (PIC) systems has been achieved via visible light-initiated RAFT polymerization of cationic monomer in the presence of anionic diblock copolymer micelles in water at 25 °C. This polymerization-induced hierarchical electrostatic self-assembly (hierarchical PIESA) implements structural hierarchy via programmable self-assembly to form multicompartment PIC micelles and their monolayer colloidal nanosheets and nanocages. The anionic micelles play decisive roles in such a hierarchical PIESA to access biologically relevant yet otherwise inaccessible multicompartment PIC systems.