Most of the recent organic solar cells (OSCs) with top-of-the-line efficiencies are processed from organic solvents with a high vapor pressure such as CF in nitrogen-filled glovebox, which is not feasible for large-area manufacturing. Herein, we cast active layers with both aromatic hydrocarbon solvents and halogenated solvents without any solvent additive or post-treatment, as well as interlayers with water and methanol in air (35% relative humidity) for efficient OSCs, except cathode electrode's evaporation is in vacuum. Compared to the PM6:Y6 system that is processed from CF, the PM6:BTP-ClBr2 system demonstrates good efficiency of 16.28% processed from CB and the device based on PM6:BTP-4Cl achieves 16.33% using TMB as its solvent for the active layer. These are among the highest efficiencies for CB- and TMB-processed binary OSCs to date. The molecular packing and phase separation length scales of each combination depend strongly on the solvent, and the overall morphology is the result of the interplay between solvent evaporation (kinetics) and materials miscibility (thermodynamics). Different solvents are required to realize the optimal morphology due to the different miscibility between the donor and acceptor. Finally, 17.36% efficiency was achieved by incorporating PC 71 BM for TMB-processed devices. Our result provides insights into the effect of processing solvent and shows the potential of realizing high-performance OSCs in conditions relevant for industrial fabrication.

Electrochemically active metal anodes, such as lithium, sodium, potassium, and zinc, have attracted great research interests in the advanced rechargeable batteries owing to their superior theoretical energy densities. Unfortunately, the metal anodes suffer from the huge volume changes with loss of active materials during the plating and stripping processes, resulting in fast capacity decay. Moreover, the random growth of dendrites on the metal anodes will penetrate the separator, causing severe safety issues. Engineering metal anodes by introducing the 2D materials are widely investigated to alleviate these issues. Benefitting from the ultrathin structure feature and unique electrical properties, 2D materials are regarded as one of the best host of metal anodes. Besides, the tunable active sites on basal plane enable 2D materials to achieve favorable interaction with metal anodes. Moreover, some 2D materials exhibit good mechanical strength and flexibility, serving as building block for the artificial solid electrolyte interphase. In this review, we mainly disclosed the correlations between the intrinsic properties of 2D materials and their functions in guiding uniform nucleation, controlling the growth of metals, and accommodating the volume change. Also, the challenges of 2D materials in metal anodes are well discussed. Finally, the future directions to develop high-performance metal anodes by taking advantage of these unique features of 2D materials are proposed.

The conversion of waste tire pyrolysis oil (WTPO) into S-doped porous carbon nanorods (labeled as WPCNs) with hierarchical pore structure is realized by a simple template-directed approach. The specific surface area of as-obtained porous carbon nanorods can reach up to 1448 m 2  g −1 without the addition of any activating agent. As the capacitive electrode, WPCNs possess the extraordinary compatibility to capacitance, different electrolyte systems as well as long-term cycle life even at a commercial-level areal mass loading (10 mg cm −2 ). Besides, only an extremely small capacitance fluctuation is observed under the extreme circumstance (−40 to 80 °C), reflecting the excellent high- and low-temperature performance. The relationship between the pore structure and capacitive behavior is analyzed by comparing WPCNs with mesopores-dominated asphalt-derived porous carbon nanorods (APCNs) and micropores-dominated activated carbon. The molecular dynamics simulation further reveals the ion diffusion and transfer ability of the as-prepared carbon materials under different pore size distribution. The total ion flow ( N T ) of WPCNs calculated by the simulation is obviously larger than APCNs and the N T ratio between them is similar with the experimental average capacitance ratio. Furthermore, this work also provides a valuable strategy to prepare the electrode material with high capacitive energy storage ability through the high value-added utilization of WTPO.

The increasing energy requirements to power the modern world has driven active research into more advanced electrochemical energy storage devices (EESD) with both high energy densities and power densities. Wide range of newly discovered materials with promising electrochemical properties has shown great potential for next-generation devices, but their performance is normally associated with contradicting demands of thin electrodes and high mass loading that can be hardly achieved for practical applications. Design of three-dimensional (3D) porous electrodes can increase the mass loading while maintaining the effective charge transport even with thick electrodes, which has proven to be efficient to overcome the limitations. 3D structures have also been demonstrated excellent structural stability to withstand strong strains and stresses generated during charge/discharge cycle. 3D printing, which can fabricate various delicate and complex structural designs, thus offering brand-new opportunities for the rational design and facile construction of next-generation EESDs. The recent developments in 3D printing of next-generation EESDs with high performance are reviewed. Advanced/multiscale electrode structures, such as hierarchically porous structure that can be constructed via high-resolution 3D printing or with post-treatment, are further emphasized. The ability of current 3D printing techniques to fulfill multimaterial printing to fulfill simple packaging will be covered.

The exploration of cheap, efficient, and durable bifunctional electrocatalysts for oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) is highly desired to push forward the commercialization of rechargeable metal–air batteries. Here, bifunctional ORR/OER electrocatalysts based on Co x P (0 <  x  < 2, i.e., Co 2 P, Co 2 P/CoP mixture, and CoP) nanoparticles (NPs) anchored on N,P-doped carbon framework (Co x P@NPC) are developed via one-step carbonization of the mixture of as-synthesized ZIF-67 and melamine–phytic acid supermolecular aggregate (MPSA). The stoichiometric ratio of resultant Co x P NPs can be rationally designed by adjusting the introduced ratio of ZIF-67 to MPSA, enabling their fabrication in a controlled manner. It is found that the as-synthesized Co 2 P@NPC exhibits the best bifunctional ORR/OER activity among the Co x P@NPC analogues, with a reversible oxygen electrode index (Δ E  =  E j10  −  E 1/2 ) down to ~0.75 V. The constructed Zn–air battery based on Co 2 P@NPC delivers a peak power density of 157 mW cm −2 and an excellent charge-discharge stability with negligible voltage decay for 140 h at 10 mA cm −2 , superior to those based on Pt/C+RuO 2 and most Co x P-based electrodes ever reported.

Graphene, as a proof-of-concept two-dimensional material, has proven to have excellent physical and chemical properties. Its derivatives, such as defective or doped graphene, are also applied as catalytic materials for metal–air batteries (MABs). MABs have been recognized as possible candidates for new-generation energy storage systems due to their ultra-high theoretical energy density. So far, graphene and its derivatives with optimized structures have been widely explored to improve the electrochemical performance in MABs. Generally speaking, perfect graphene crystalline is inert for many catalytic processes, while defects and heteroatoms can endow graphene with high activity for many electrocatalytic reactions. Under this circumstance, recent progress is summarized for defective/doped graphene as air cathodes in aqueous or organic MABs, which are actually different electrochemical systems with distinct requirements for air cathodes. Also, the relationship is clarified between graphene defects/doping and electrocatalytic mechanisms that can be the guidance for catalyst design. Future directions are also prospected for the development of graphene-based MAB cathodes.