Microsized silicon oxide (SiO) has become a highly potential anode material for practical lithium‐ion batteries (LIBs) in virtue of its low cost and high capacity. However, its commercialization is still impeded by the low inherent conductivity and nonignorable volume expansion of SiO in the lithiation/delithiation processes. Herein, an in situ catalytic growth approach is developed for grafting N‐doped bamboo‐like carbon nanotubes (NCNTs) onto the polydopamine‐coated SiO microparticles, yielding a unique adina rubella‐like SiO@NC‐NCNT composite. The cross‐sectional scanning electron microscopy images reveal that the flexible middle‐carbon layer plays a crucial role in alleviating volume expansions and improving structural stability of SiO@NC‐NCNTs. Theoretical density functional theory simulation results further prove that the rational construction of ternary heterostructure can effectively balance lithium adsorption energies and greatly improve conductivity of SiO@NC‐NCNTs. As a result, the as‐fabricated SiO@NC‐NCNTs LIB anode shows a high reversible specific capacity of 1103.7 mA h g−1 at 0.2 A g−1 after 200 cycles with a high retention of 99.6% and an outstanding rate capability of 569 mA h g−1 at 5000 mA g−1. The strategy developed herein demonstrates a feasible avenue for developing high‐energy SiO‐based anodes for LIBs.

Composite hydrogels--macroscopic hydrogels with embedded microgel particles--are expected to respond to external stimuli quickly because microgels swell much faster than bulky gels. In this work, the kinetics of the pH-induced swelling of a composite hydrogel are studied using turbidity measurements. The embedded microgel is a pH- and thermosensitive poly(N-isopropylacrylamide-co-acrylic acid) microgel and the hydrogel matrix is polyacrylamide. A rapid pH-induced swelling of the embedded microgel particles is observed, confirming that composite hydrogels respond faster than ordinary hydrogels. However, compared with the free microgels, the swelling of the embedded microgel is much slower. Diffusion of OH(-) into the composite hydrogel film is identified as the main reason for the slow swelling of the embedded microgel particles, as the time of the pH-induced swelling of this film is comparable to that of OH(-) diffusion into the film. The composition of the hydrogel matrix does not significantly change the characteristic swelling time of the composite hydrogel film. However, the swelling pattern of the film changes with composition of the hydrogel matrix.

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The ORCID identification number(s) for the author(s) of this article can be found under https://doi.org/10.1002/smll.202301579. Figure 6. The calculated Gibbs free energy for hydrogen evolution reduction of different N-sites marked in red dash cycles in the heterostructure of triazine/heptazine.