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Highlights: An ultra-microporous carbon material simultaneously with high specific surface area (1554 m2 g−1) and packing density (1.18 g cm−3) is designed and fabricated. The resulting carbon material integrates the high gravimetric and volumetric capacitance (430 F g−1 and 507 F cm−3 at 0.5 A g−1) and thereof provides the robust all-solid-state cellulose supercapacitor with high areal and volumetric density.A breakthrough in advancing power density and stability of carbon-based supercapacitors is trapped by inefficient pore structures of electrode materials. Herein, an ultra-microporous carbon with ultrahigh integrated capacitance fabricated via one-step carbonization/activation of dense bacterial cellulose (BC) precursor followed by nitrogen/sulfur dual doping is reported. The microporous carbon possesses highly concentrated micropores (~ 2 nm) and a considerable amount of sub-micropores (< 1 nm). The unique porous structure provides high specific surface area (1554 m2 g−1) and packing density (1.18 g cm−3). The synergistic effects from the particular porous structure and optimal doping effectively enhance ion storage and ion/electron transport. As a result, the remarkable specific capacitances, including ultrahigh gravimetric and volumetric capacitances (430 F g−1 and 507 F cm−3 at 0.5 A g−1), and excellent cycling and rate stability even at a high current density of 10 A g−1 (327 F g−1 and 385 F cm−3) are realized. Via compositing the porous carbon and BC skeleton, a robust all-solid-state cellulose-based supercapacitor presents super high areal energy density (~ 0.77 mWh cm−2), volumetric energy density (~ 17.8 W L−1), and excellent cyclic stability. [ABSTRACT FROM AUTHOR]

• A largescale salt-template method is developed to prepare conformable amorphous TiO 2 mesoporous nanosheets. • Interfacial strain between salt and TiO 2 is revealed to assist to suppress the amorphous-to-crystalline transformation. • This amorphous TiO 2 possesses ultrathin structure and rich mesopores that are beneficial for fast lithium-storage. • Remarkable high-rate long-term cycling stability (103 mA h g−1 at 6 A g−1 after 1000 cycles) are demonstrated. Amorphous nanomaterials recently have been demonstrated as a new type of high-power electrodes for many electrochemical energy-storage devices owing to their structural advantages of large surface area, shortened ion-diffused pathway, rich surficial defects and loosely packed structure; However, it is still challenging to prepare amorphous nanomaterials on a large scale via low-cost sol–gel method due to the easy amorphous-to-crystalline transformation upon post calcination process. Herein, we develop a simple and scalable approach to prepare amorphous TiO 2 mesoporous nanosheets by using the potassium chloride (KCl) as the template. The experimental results combined with density functional theory (DFT) calculations have revealed that the interfacial strain between the KCl and TiO 2 suppresses the crystallization of TiO 2 , which maintains amorphous characteristics even at a relative high temperature of 400 °C. Benefiting from short Li+-diffused distance, accessible mesoporous structure, and surface pseudo-capability, the amorphous TiO 2 nanosheet electrode exhibits fast and durable lithium-storage/-release ability, such as delivering a high reversible capacity of 103 mA h g−1 at 6 A g−1 after 1000 cycles. This study may pave a new way for the design of amorphous nanoarchitectures, and highlight the function of the templates, not only leading to the formation of various morphologies, but also affecting the surface microstructure. [ABSTRACT FROM AUTHOR]

Highlights: An ultra-microporous carbon material simultaneously with high specific surface area (1554 m2 g−1) and packing density (1.18 g cm−3) is designed and fabricated. The resulting carbon material integrates the high gravimetric and volumetric capacitance (430 F g−1 and 507 F cm−3 at 0.5 A g−1) and thereof provides the robust all-solid-state cellulose supercapacitor with high areal and volumetric density. A breakthrough in advancing power density and stability of carbon-based supercapacitors is trapped by inefficient pore structures of electrode materials. Herein, an ultra-microporous carbon with ultrahigh integrated capacitance fabricated via one-step carbonization/activation of dense bacterial cellulose (BC) precursor followed by nitrogen/sulfur dual doping is reported. The microporous carbon possesses highly concentrated micropores (~ 2 nm) and a considerable amount of sub-micropores (< 1 nm). The unique porous structure provides high specific surface area (1554 m2 g−1) and packing density (1.18 g cm−3). The synergistic effects from the particular porous structure and optimal doping effectively enhance ion storage and ion/electron transport. As a result, the remarkable specific capacitances, including ultrahigh gravimetric and volumetric capacitances (430 F g−1 and 507 F cm−3 at 0.5 A g−1), and excellent cycling and rate stability even at a high current density of 10 A g−1 (327 F g−1 and 385 F cm−3) are realized. Via compositing the porous carbon and BC skeleton, a robust all-solid-state cellulose-based supercapacitor presents super high areal energy density (~ 0.77 mWh cm−2), volumetric energy density (~ 17.8 W L−1), and excellent cyclic stability. [ABSTRACT FROM AUTHOR]

Advancement in developing superelastic carbon aerogels is highly demanded in new industry sectors, particularly in wearable functional electronics for artificial intelligence applications. However, it is very challenging to increase the compressive strength and electrical conductivity while lowering the density of carbon aerogels. Here, an ultralight and superelastic hard carbon aerogel with in situ ultrafine carbon crystals is reported. Based on a novel precursor prepared from self‐assembling bacterial cellulose and thiourea molecules, the resulting aerogel possesses a unique cellular structure and simultaneously exhibits remarkable compressive and electrical properties with ultralow density in addition to excellent compressive cyclability. Specifically, the normalized compression strength and electrical conductivity are up to 20 and 10 times, respectively, of reported carbon aerogels. Armed with the compressed aerogel electrodes, the supercapacitor exhibits excellent electrochemical performance in areal capacitance, rate capability, and high‐power cyclic stability. Furthermore, the supercapacitor displays distinguished pressure‐response capacitive signal and excellent signal cyclicality. This study provides a unique carbon aerogel for advanced wearable monitoring and energy storage systems. [ABSTRACT FROM AUTHOR]

Lithium metal batteries (LMBs) possessing ultrahigh energy density are promising next‐generation battery systems, but the short cycle life and safety concerns caused by the uncontrollable growth of lithium dendrites impede their broad applications. Herein, to address these issues, an ultrarobust composite gel electrolyte (CGE) that can effectively stabilize ion deposition for LMBs is designed via fabricating a specially structured aerogel as the matrix. The gel electrolyte matrix with a 3D interconnected highly porous structures and good affinity with liquid electrolytes is fabricated via compositing bacterial cellulose (BC) and Li0.33La0.557TiO3 nanowires (LLTO NWs) into an aerogel. The composite aerogel matrix demonstrates excellent wettability and liquid electrolyte uptake (586 ± 5%), and the resulting CGE presents exceptional Young's modulus of 1.15 GPa and an extremely high lithium‐ion transference number of 0.88. More significantly, the synergistic effect from the robust BC skeleton and LLTO NWs enabling stable ion deposition effectively suppresses the growth of lithium dendrites. Armed with the CGE, ultrastable symmetric Li/Li cells demonstrate a long cycle life of 1200 h and highly stable performance even at a high current density of 5 mA cm−2. Furthermore, half cells with the CGE exhibit remarkable enhancement in capacity, cycling stability, and rate performance. [ABSTRACT FROM AUTHOR]

Inverted positive‐intrinsic‐negative (p‐i‐n) perovskite solar cells (IPSCs) have attracted widespread attention due to their low fabrication temperature, good stability in ambient air, and the potential for use in flexible and tandem devices. In recent years, self‐assembled monolayers (SAMs) have been investigated as a promising hole‐selective contact for IPSCs, leading to an impressive record efficiency of about 26%, which is comparable to that of the regular n‐i‐p counterparts. This review focuses on the progress of SAM‐based IPSCs from the perspective of energy level matching, defect passivation, interface carrier extraction, and SAMs’ stability improvement, as well as the advances in up‐scalable fabrication of SAMs and perovskite layers for efficient solar modules and tandem devices. A cost analysis of the SAMs and other commonly used hole‐selective materials is conducted to evaluate their cost‐effectiveness for photovoltaic applications. Finally, the future challenges are pointed out and the perspectives on how to up‐scale SAM‐based IPSCs and improve their long‐term operational stability are provided. [ABSTRACT FROM AUTHOR]

Ternary organic solar cells (OSCs) have attracted intensive studies due to their promising potential for attaining high-performing photovoltaics, whereas there has been an opening challenge in minimizing the open circuit voltage (Voc) loss while retaining the optimal carrier extraction in the multiple mixture absorbers. Here, we systemically investigate a ternary absorber comprised of two acceptors and a donor, in which the resultant Voc and fill factor are varied and determined by the ratios of acceptor components as a result of the unbalance of non-radiative recombination rates and charge transport. The transient absorption spectroscopy and electroluminescence techniques verify two distinguishable charge-transfer (CT) states in the ternary absorber, and the mismatch of non-radiative recombination rates of those two CT states is demonstrated to be associated with the Voc deficit, whilst the high-emissive acceptor molecule delivers inferior electron mobility, resulting in poor charge transport and a subpar fill factor. These findings enable us to optimize the mixture configuration for attaining the maximal-performing devices. Our results not only provide insight into maximizing the photovoltage of organic solar cells but can also motivate researchers to further unravel the photophysical mechanisms underlying the intermolecular electronic states of organic semiconductors. [ABSTRACT FROM AUTHOR]

Abstract A novel three-dimensional hierarchical ternary aerogel of TiO 2 nanoparticles@porous carbon nanofibers-reduced graphene oxide (TiO 2 @PCNF-GA) was designed as an advanced anode for lithium-ion capacitors. TiO 2 @PCNFs were first fabricated by electrospinning assisted by carbonization and a post-etching process, and then assembled into reduced graphene oxide aerogels (GAs) to obtain the TiO 2 @PCNF-GAs. The uniform distribution of the ultrafine TiO 2 nanoparticles in the PCNFs inhibits the aggregation of the TiO 2 nanoparticles. Meanwhile, the interconnected three-dimensional network constructed from the TiO 2 @PCNFs and the GAs inhibits the aggregation of the TiO 2 @PCNFs. Moreover, the hierarchical porous structure of the TiO 2 @PCNF-GAs affords numerous Li-ion transport paths. Therefore, the lithium-ion capacitor composed of the TiO 2 @PCNF-GAs anode and an activated carbon cathode exhibits high energy density versus power density (79.7 Wh kg−1 versus 75 W kg−1, 15.0 Wh kg−1 versus 15 kW kg−1) with superior cycle stability (93.3% retention after 10000 cycles at 5.0 A g−1). [ABSTRACT FROM AUTHOR]

Hybrid chemical vapor deposition (HCVD) is a promising method for the up‐scalable fabrication of perovskite solar cells/modules (PSCs/PSMs). However, the efficiency of the HCVD‐based perovskite solar cells still lags behind the solution‐processed PSCs/PSMs. In this work, the oxygen loss of the electron transport layer of SnO2 in the HCVD process and its negative impact on solar cell device performance are revealed. As the counter‐measure, potassium sulfamate (H2KNO3S) is introduced as the passivation layer to both mitigate the oxygen loss issue of SnO2 and passivate the uncoordinated Pb2+ in the perovskite film. In parallel, N‐methylpyrrolidone (NMP) is used as the solvent to dissolve PbI2 by forming the intermediate phase of PbI2•NMP, which can greatly lower the energy barrier for perovskite nucleation in the HCVD process. The perovskite seed is employed to further modulate the kinetics of perovskite crystal growth and improve the grain size. The resultant solar cells yield a champion power conversion efficiency (PCE) of 21.98% (0.09 cm2) with a stable output performance of 21.15%, and the PCEs of the mini‐modules are 16.16% (22.4 cm2, stable output performance of 14.72%) and 12.12% (91.8 cm2). Furthermore, the unencapsulated small area device shows an outstanding operational stability with a T80 lifetime exceeding 4000 h. [ABSTRACT FROM AUTHOR]

Building bimodal structures for air-filters is promising to reduce the airflow resistance without sacrificing the filtration efficiency. To do so, multi-jet electrospinning is among the most broadly used methods, yet the interplay between single fibers in electrospinning, which is significant to their morphologies, is overlooked. In this study, we report a wettability difference-driven strategy to fabricate a bimodal protein fabric with superior filtration performance. We surprisingly find that only by co-spinning of two proteins, zein and gelatin, with different wettability between them, a drastic change of fiber diameters is spontaneously achieved. The generated protein-blend fabric possesses bimodally distributed diameters of 270 nm for gelatin fibers and of 1.12 µm for zein fibers; both pure protein fabrics via single-jet electrospinning have diameters unimodally distributed in the range of 500–700 nm. The bimodal protein-blend fabric delivers exceptional removal efficiencies of 99.67% for PM 2.5 and 98.80% for PM 0.3 , yielding an ultra-low airflow resistance of 38 Pa. The PM 2.5 removal efficiency retains to be 96.04% after filtering 1000 L polluted air, indicating a good long-term performance. This study brings about a new insight into fabrication of bimodal structures using multi-jet electrospinning method and promotes the development of natural products for broad applications. [Display omitted] • A new electrospinning concept from wettability difference is used to fabricate bimodal air-filters. • By co-spinning of two proteins with different wettability, a drastic change of fiber diameters is achieved. • The bimodal protein air-filter removes 99.67% PM 2.5 and 98.80% PM 0.3 in the air at a low airflow resistance of 38 Pa. [ABSTRACT FROM AUTHOR]