The dramatically increasing demand of high‐energy lithium‐ion batteries (LIBs) urgently requires advanced substitution for graphite‐based anodes. Herein, inspired from the extra capacity of lithium storage in solid‐electrolyte interface (SEI) films, layered hydroxide cobalt acetates (LHCA, Co(Ac)0.48(OH)1.52·0.55H2O) are introduced as novel and high‐efficiency anode materials. Furthermore, ultrathin LHCA nanoplates are face‐to‐face anchored on the surface of graphene nanosheets (GNS) through a facile solvothermal method to improve the electronic transport and avoid agglomeration during repeated cycles. Profiting from the parallel structure, LHCA//GNS nanosheets exhibit extraordinary long‐term and high‐rate performance. At the current densities of 1000 and 4000 mA g−1, the reversible capacities maintain ≈1050 mAh g−1 after 200 cycles and ≈780 mAh g−1 after 300 cycles, respectively, much higher than the theoretical value of LHCA according to the conversion mechanism. Fourier transform infrared spectroscopy confirms the conversion from acetate to acetaldehyde after lithiation. A reasonable mechanism is proposed to elucidate the lithium storage behaviors referring to the electrocatalytic conversion of OH groups with Co nanocatalysts. This work can help further understand the contribution of SEI components (especially LiOH and LiAc) to lithium storage. It is envisaged that layered transition metal hydroxides can be used as advanced materials for energy storage devices.

721wileyonlinelibrary.com www.particle-journal.com www.MaterialsViews.com COMMUNICATION mechanical fl exibility, and high lithium storage capacity (744 mAh g −1 ). [ 9 ] All these attractive features could greatly improve the electronic conductivity, and increase the surface area of electrodes for higher rate capability. It is reasonable and effi cient to combine the nanotechnology, mesoporous structure, and GNS for high-performance anode materials. [ 10 ] To the best of our knowledge, the preparation of mesoporous Mn 3 O 4 /GNS nanohybrids (M-Mn 3 O 4 /GNS) is still a challenge and no related works were reported up to today. Herein, we introduced a novel and facile gel-like fi lm (GF) synthetic approach toward uniformly dispersed mesoporous Mn 3 O 4 nanobeads (20-50 nm) on the GNS surface. Profi ting from the unique structures, the obtained M-Mn 3 O 4 /GNS exhibited an extremely high reversible capacity (1135 mAh g −1 at 100 mA g −1 after 240 cycles, without any loss) and good rate performances. The GF synthetic method is facile and template-free, and might provide a new path to fabricate mesoporous GNS-based nanocomposites. Moreover, the promising architecture can enlighten us on maximizing the potentials of active materials for lithium storage, supercapacitors, Li-air batteries, and other fi elds with electrochemical catalysts.The M-Mn 3 O 4 /GNS nanohybrids were fabricated by a facile GF method. In conventional methods for GNS-based composites, it is generally necessary and benefi cial to modify the GNS surface with negatively charged groups such as COOH, OH, and NH 2 . [ 11 ] By contrast, the GF method was more facile, without the modifi cation of GNS ahead and involving only two steps: solvothermal and hydrothermal reactions ( Scheme 1 ). During the solvothermal treatment, ethylene glycol functioned as a chelating and dispersing agent at the same time. The C O groups of ethylene glycol possess a pair of electrons and its ability to be a donor of oxygen atoms that enable it to couple with Mn 2+ ions and to form a thermodynamically favorable polymer complex as a Mn-containing gel-like fi lm (MGF) located on the GNS surface. [ 12 ] During the subsequent hydrothermal reaction, the MGF can transform into mesoporous Mn 3 O 4 nanobeads with the help of H 2 O 2 .The morphology and components of the samples were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), energydispersive spectrometer (EDS), and Fourier-transform infrared apectroscopy (FT-IR) to confi rm the GF method mentioned above. As shown Figure 1 , all the peaks of GNS, M-Mn 3 O 4 / GNS, nonporous Mn 3 O 4 /GNS (N-Mn 3 O 4 /GNS), and pure Mn 3 O 4 were in good agreement with the standard cards of GNS and tetragonal spinel Mn 3 O 4 (JCPDS 24-0734), indicating that no impurity existed. For MGF/GNS, the sharp peaks located at around 26° belonged to the commercial few-layered GNS,

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Metal and metal oxides are extremely competitive in various applications such as catalysis and energy storage, while the intrinsically unsatisfactory ion/electron conductivity and/or large volume swing severely inhibit their inherent potentials. Quantum dots (QDs) can significantly promote the conductivity, buffer volume variation, and introduce novel physical/chemical properties, especially in cooperation with mesoporous carbon (MC), and hence are attracting ever‐increasing attention. However, it is still a worldwide challenge to exploit a facile, efficient, environmentally benign, commercially applicable, and, in particular, universal method for varied QDs/MC hybrids. In this work, a powerful approach is proposed on basis of corn straw piths, and a synthetic mechanism is proposed and investigated systematically. According to this route, Ni, Co, Cu, and MnO QDs/MC nanoplates are successfully fabricated. As a typical example, ultrasmall Ni QDs (5–7 nm) are homogeneously distributed on the large surface of MC nanoplates and exhibit a reversible capacitance of 2420 F g−1 at 500 mA g−1 and rate performance. This work discloses a new and paramount path to exploit versatile QDs/MC hybrids for promising applications such as lithium ion batteries, solar cells, Li–air batteries, and other promising fields with electrochemical catalysts.

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