Trihigh tricontinuous graphene cathode enables a 1.1 s charge, 250,000 cycle life, wide temperature range Al-ion battery.

A conceptually new defect-free principle is proposed for designing graphene cathode of aluminum-ion battery: the fewer the defects, the better the performances. Developed through scalable approach, defect-free graphene aerogel cathode affords high capacity of 100 mAh g under an ultrahigh rate of 500 C, exceeding defective graphene and previous reports. This defect-free principle can guide us to fabricate better graphene-based electrodes.

Graphene aerogel microlattices (GAMs) hold great prospects for many multifunctional applications due to their low density, high porosity, designed lattice structures, good elasticity, and tunable electrical conductivity. Previous 3D printing approaches to fabricate GAMs require either high content of additives or complex processes, limiting their wide applications. Here, a facile ion‐induced gelation method is demonstrated to directly print GAMs from graphene oxide (GO) based ink. With trace addition of Ca2+ ions as gelators, aqueous GO sol converts to printable gel ink. Self‐standing 3D structures with programmable microlattices are directly printed just in air at room temperature. The rich hierarchical pores and high electrical conductivity of GAMs bring admirable capacitive performance for supercapacitors. The gravimetric capacitance (Cs) of GAMs is 213 F g−1 at 0.5 A g−1 and 183 F g−1 at 100 A g−1, and retains over 90% after 50 000 cycles. The facile, direct 3D printing of neat graphene oxide can promote wide applications of GAMs from energy storage to tissue engineering scaffolds.

Polymer-based thermal interface materials (TIMs) with excellent thermal conductivity and electrical resistivity are in high demand in the electronics industry. In the past decade, thermally conductive fillers, such as boron nitride nanosheets (BNNS), were usually incorporated into the polymer-based TIMs to improve their thermal conductivity for efficient heat management. However, the thermal performance of those composites means that they are still far from practical applications, mainly because of poor control over the 3D conductive network. In the present work, a high thermally conductive BNNS/ epoxy composite is fabricated by building a nacre-mimetic 3D conductive network within an epoxy resin matrix, realized by a unique bidirectional freezing technique. The as-prepared composite exhibits a high thermal conductivity (6.07 W m −1 K −1 ) at 15 vol% BNNS loading, outstanding electrical resistivity, and thermal stability, making it attractive to electronic packaging applications. In addition, this research provides a promising strategy to achieve high thermal conductive polymer-based TIMs by building efficient 3D conductive networks.The ORCID identification number(s) for the author(s) of this article can be found under https://doi.org/10.1002/adfm.201900412. graphene [12] (1-16 W m −1 K −1 ), and carbon nanotubes [13] (CNTs, 0.5-5 W m −1 K −1 ) are usually included in the polymer matrix. Among all those fillers, boron nitride (BN) is particularly outstanding for its high thermal conductivity, excellent electrical insulation, and low cost. [14] During the last decade, although many efforts have been made to develop BN-based polymer composite, [15][16][17][18] its real application as TIM is greatly hindered for its moderate thermal conductivity. This could be mainly attributed to the insufficient manipulation of the 3D conductive network. For the same reason, currently reported composites are usually thin films although there is an urgent need for bulk BN-based composite with high thermal conductivity.Here, a BN/epoxy composite with a nacre-mimetic 3D conductive network was constructed by a bidirectional freezing technique. [19][20][21] The boron nitride nanosheets (BNNS) were assembled into an aerogel with long-range aligned lamellar layers, followed by infiltration of epoxy resin. The highly organized 3D conductive network provides prolonged phonon pathways, yielding a much higher thermal conductivity (6.07 W m −1 K −1 ) at a relatively low BN loading (15 vol%) comparing to the similar composites in the literature. Together with its excellent electrical resistivity (2 × 10 12 Ω cm) and thermal stability (glass transition temperature: 120 °C), our composite may find wide applications including TIM for the advanced electronic packaging technology. Keywords3D conductive network, bidirectional freezing, boron nitride, long-range lamellar structure, thermal interface material

Continuous MXene/graphene fibers are fabricatedviawet-spinning assembly strategy, from which fiber-constructed supercapacitors are obtained that exhibit both high capacitance and flexibility.

Materials combining lightweight, robust mechanical performances, and multifunctionality are highly desirable for engineering applications. Graphene aerogels have emerged as attractive candidates. Despite recent progresses, the bottleneck remains how to simultaneously achieve both strength and resilience. While multiscale architecture designs may offer a possible route, the difficulty lies in the lack of design guidelines and how to experimentally achieve the necessary structure control over multiple length scales. The latter is even more challenging when manufacturing scalability is taken into account. The Thalia dealbata stem is a naturally porous material that is lightweight, strong, and resilient, owing to its architecture with three-dimensional (3D) interconnected lamellar layers. Inspired by such, we assemble graphene oxide (GO) sheets into a similar architecture using a bidirectional freezing technique. Subsequent freeze-drying and thermal reduction results in graphene aerogels with highly tunable 3D architectures, consequently an unusual combination of strength and resilience. With their additional electrical conductivity, these graphene aerogels are potentially useful for mechanically switchable electronics. Beyond such, our study establishes bidirectional freezing as a general method to achieve multiscale architectural control in a scalable manner that can be extended to many other material systems.

Carbon aerogels demonstrate wide applications for their ultralow density, rich porosity, and multifunctionalities. Their compressive elasticity has been achieved by different carbons. However, reversibly high stretchability of neat carbon aerogels is still a great challenge owing to their extremely dilute brittle interconnections and poorly ductile cells. Here we report highly stretchable neat carbon aerogels with a retractable 200% elongation through hierarchical synergistic assembly. The hierarchical buckled structures and synergistic reinforcement between graphene and carbon nanotubes enable a temperature-invariable, recoverable stretching elasticity with small energy dissipation (~0.1, 100% strain) and high fatigue resistance more than 106 cycles. The ultralight carbon aerogels with both stretchability and compressibility were designed as strain sensors for logic identification of sophisticated shape conversions. Our methodology paves the way to highly stretchable carbon and neat inorganic materials with extensive applications in aerospace, smart robots, and wearable devices.

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