The preparation and optoelectronic response of flexible composites via noncovalent coupling of quantum dots to chemically converted graphene is presented. The photoinduced charge transfer is confirmed by photoconductivity measurements and the photosensitivity is improved with increasing loadings of quantum dots. This opens up a new effective route to form composites for future large‐area flexible and transparent optoelectronic devices.

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Silicon (Si), a promising candidate for next-generation lithium-ion battery anodes, is still hindered by its volume change issue for (de)­lithiation, thus resulting in tremendous capacity fading. Designing carbon-modified Si materials with a void-preserving structure (Si@void@C) can effectively solve this issue. The preparation of Si@void@C, however, usually depended on template-based routes or chemical vapor deposition, which involve toxic reagents, tedious operation processes, and harsh conditions. Here, a facile templateless approach for preparing Si@void@C materials is reported through controlling the growth kinetics of resin, without the use of toxic hydrofluoric acid or harsh conditions. This approach allows great flexibility in tuning the crucial parameters of Si@void@C, such as the carbon shell thickness, the reserved void size, and the number of Si cores coated by a carbon shell. The optimized Si@void@C delivers a large specific capacity (1993.2 mAh g–1 at 0.1 A g–1), excellent rate performance (799.4 mAh g–1 at 10.0 A g–1), and long cycle life (73.5% capacity retention after 1000 cycles at 2.0 A g–1). In addition, a full cell fabricated with a Si@void@C anode and commercial LiFePO4 cathode also displays an impressive cycling performance.

Structural modulation endows electrochemical hybrids with promising energy storage properties owing to their adjustable interfacial and/or electronic characteristics. For MXene‐based materials, however, the facile but effective strategies for tuning their structural properties at nanoscale are still lacking. Herein, 3D crumpled S‐functionalized Ti3C2Tx substrate is rationally integrated with Fe3O4/FeS heterostructures via coprecipitation and subsequent partial sulfurization to induce a highly active and stable electrode architecture. The unique heterostructures with tuned electronic properties can induce improved kinetics and structural stability. The surface engineering by S terminations on the MXene further unlocks extra (pseudo)capacitive lithium storage. Serving as anode for lithium storage, the optimized electrode delivers an excellent long‐term cycling stability (913.9 mAh g−1 after 1000 cycles at 1 A g−1) and superior rate capability (490.4 mAh g−1 at 10 A g−1). Moreover, the (de)lithiation pathways associated with energy storage mechanisms are further revealed by operando X‐ray diffraction, in situ electroanalytical techniques, and first‐principles calculations. The hybrid electrode is proved to undergo stepwise phase transformations during discharging but a relatively uniform reconversion during charging, suggesting an asymmetric conversion mechanism. This work provides a novel strategy for designing high‐performance hybrids and paves the way for in‐depth understanding of complex lithium intercalation and conversion reactions.

A 3D lithiophilic N-doped graphene/nickel foam (NGNF) scaffold to host Li has been successfully prepared by a simple hydrothermal method. This scaffold can improve the poor lithiophilicity of nickel foam (NF) due to the presence of N-doped graphene (NG) with lithiophilic functional groups while maintaining its 3D porous electrode structure, leading to uniform Li plating/stripping.

Spinel Li 4 Ti 5 O 12 has become an alternative material to replace graphite anodes in terms of solving safety issues and improving battery life-time. Unfortunately, as Li 4 Ti 5 O 12 is an insulator, the low electrical conductivity becomes a major drawback, as it is unfavorable to higher rate capability. In addition to the low electronic conductivity, severe gassing during charge/discharge cycles is a critical but often-overlooked problem of Li 4 ExperimentalMaterials synthesis.-Anatase TiO 2 (220 nm in average particle diameter and 99.5% in purity, Hangzhou Wanjing New Material Co., Ltd) and Li 2 CO 3 (99.9% in purity, Shanghai China Lithium Industrial Co., Ltd.) were used as raw materials. The starting coarse Li 4 Ti 5 O 12 was prepared by a solid-state reaction method as described in a previous work. 26,27 The stoichiometric amounts of Li 2 CO 3 and anatase TiO 2 with molar ratio of Li: Ti = 0.82:1 were mixed with ethanol as dispersant by planetary ballmilling. The ball-milled mixture was heated in a furnace at 800• C in air for 18 h to obtain the coarse materials were first ball-milled without a carbon source and with 5 wt% pitch as a carbon source using water as a dispersant for 1.5 h, respectively. The resultant slurry was then spray dried to obtain the precursors individually. Finally, two precursors were all annealed at 650• C for 6 h in an Ar atmosphere to obtain the final materials.Characterization.-X-ray diffraction (XRD) patterns of the samples were recorded on a Rigaku diffractometer using Cu Kα irradiation. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) images were obtained on a Nova NanoSEM 430 and Tecnai F20.

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Although Na metal is regarded as one of the most promising anode materials for Na-based batteries because of its high specific capacity (1166 mA h g–1) and low redox potential (−2.71 V versus the standard hydrogen electrode), many issues, such as dendrite-induced safety concerns, low efficiency, and poor cyclability, severely impede its practical application. Herein, to alleviate the abovementioned problems, a nitrogen-doped graphene-modified three dimensional nickel foam framework was constructed as the host material for Na plating. The sodiophilic N-containing functional groups in the graphene structure can effectively reduce the nucleation overpotential of Na, guide the homogeneous Na-ion flux, regularize the electric field distribution, and eventually inhibit Na dendrite formation. As a result, the Na composite metal anode can be cycled reversibly free from dendrite obsessions with a high Coulombic efficiency exceeding 99% at 0.5 mA cm–2, 1 mA h cm–2 for at least 800 cycles and 99% at 1 mA cm–2, 2 mA h cm–2 for at least 200 cycles. Based on this anode, a symmetric cell with ultralow voltage polarization (∼11 mV) and long-running lifespan (1000 h at 1 mA cm–2 for 1 mA h cm–2) can be realized. Furthermore, a full cell coupled with a Na3V2(PO4)3 cathode delivers a prolonged lifespan (250 cycles at 2 C) and excellent rate performances, demonstrating a facile but effective avenue to achieve Na metal anode stabilization.