Construction of Janus carbon particles with controllable morphology and their application in lithium battery anode materials†

Janus particles are a class of materials that exhibit both surface morphology and chemical properties with asymmetry. However, at present, precise control over the structure and composition of Janus particles still faces numerous challenges. Conventional seed emulsion polymerization methods require heating to induce phase separation after seed swelling, leading to extended reaction periods. In light of this, we propose a novel photo-induced seed swelling polymerization approach. This method employs non-crosslinked polyglycerol methacrylate (poly(GMA)) as seed particles, utilizing 4-vinylpyridine (4-VP) as the functional monomer and divinylbenzene (DVB) as the cross-linker. The aqueous phase consists of polyvinyl alcohol (PVA) and sodium dodecyl sulfate (SDS), with 2,2-dimethoxy-2-phenylacetophenone (DMPA) as the photo-initiator. By adjusting parameters such as seed quantity, type of porogen, and porogen volume ratio, diverse morphologies including octopus-like, jellyfish-like, snowman-like, and half raspberry-like Janus particles are successfully synthesized. Subsequently, Janus carbon particles are obtained through calcination and employed as anode materials in lithium-ion batteries. The electrochemical performance of Janus carbon particles is assessed using cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), rate capability tests, constant current charge–discharge measurements, and cycling performance evaluation. These tests indicate the excellent electrochemical properties of the material. Our research provides a valuable strategy for creating Janus carbon particles with controlled morphologies.