In this work, twinned anhydrous guanine β microplatelets were synthesized for the first time in the presence of a polyvinylpyrrolidone. The twinning angle of the two c axes for the synthetic and biogenic twinned guanine crystals is 84°, very similar to each other.

The rational design and controllable fabrication of electrode materials with tailored structures and superior performance is highly desirable for the next-generation lithium ion batteries (LIBs). In this work, a novel three-dimensional (3D) graphite foam (GF)@SnO nanorod arrays (NRAs)@polyaniline (PANI) hybrid architecture was constructed via solvothermal growth followed by electrochemical deposition. Aligned SnO NRAs were uniformly grown on the surface of GF, and a PANI shell with a thickness of ∼40 nm was coated on individual SnO nanorods, forming a SnO@PANI core-shell structure. Benefiting from the synergetic effect of 3D GF with large surface area and high conductivity, SnO NRAs offering direct pathways for electrons and lithium ions, and the conductive PANI shell that accommodates the large volume variation of SnO, the binder-free, integrated GF@SnO NRAs@PANI electrode for LIBs exhibited high capacity, excellent rate capability, and good electrochemical stability. A high discharge capacity of 540 mAh g (calculated by the total mass of the electrode) was achieved after 50 cycles at a current density of 500 mA g. Moreover, the electrode demonstrated superior rate performance with a discharge capacity of 414 mAh g at a high rate of 3 A g.