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Highlights: A class of solvent-free covalent organic framework (COF) single-ion conductors (Li-COF@P) has been designed via ion–dipole interaction as opposed to traditional ion–ion interaction, promoting ion dissociation and Li+ migration through directional ionic channels. The Li-COF@P enabled long cycle life (88.3% after 2000 cycles) in all-solid-state Li organic batteries (ASSLOBs) under ambient operating conditions, which outperformed those of previously reported ASSOLBs. This Li-COF@P strategy holds promise as a viable alternative to the currently prevalent inorganic solid electrolytes. Single-ion conductors based on covalent organic frameworks (COFs) have garnered attention as a potential alternative to currently prevalent inorganic ion conductors owing to their structural uniqueness and chemical versatility. However, the sluggish Li+ conduction has hindered their practical applications. Here, we present a class of solvent-free COF single-ion conductors (Li-COF@P) based on weak ion–dipole interaction as opposed to traditional strong ion–ion interaction. The ion (Li+ from the COF)–dipole (oxygen from poly(ethylene glycol) diacrylate embedded in the COF pores) interaction in the Li-COF@P promotes ion dissociation and Li+ migration via directional ionic channels. Driven by this single-ion transport behavior, the Li-COF@P enables reversible Li plating/stripping on Li-metal electrodes and stable cycling performance (88.3% after 2000 cycles) in organic batteries (Li metal anode||5,5'-dimethyl-2,2'-bis-p-benzoquinone (Me2BBQ) cathode) under ambient operating conditions, highlighting the electrochemical viability of the Li-COF@P for all-solid-state organic batteries. [ABSTRACT FROM AUTHOR]

Rechargeable batteries, typically represented by lithium-ion batteries, have taken a huge leap in energy density over the last two decades. However, they still face material/chemical challenges in ensuring safety and long service life at temperatures beyond the optimum range, primarily due to the chemical/electrochemical instabilities of conventional liquid electrolytes against aggressive electrode reactions and temperature variation. In this regard, a gel polymer electrolyte (GPE) with its liquid components immobilized and stabilized by a solid matrix, capable of retaining almost all the advantageous natures of the liquid electrolytes and circumventing the interfacial issues that exist in the all-solid-state electrolytes, is of great significance to realize rechargeable batteries with extended working temperature range. We begin this review with the main challenges faced in the development of GPEs, based on extensive literature research and our practical experience. Then, a significant section is dedicated to the requirements and design principles of GPEs for wide-temperature applications, with special attention paid to the feasibility, cost, and environmental impact. Next, the research progress of GPEs is thoroughly reviewed according to the strategies applied. In the end, we outline some prospects of GPEs related to innovations in material sciences, advanced characterizations, artificial intelligence, and environmental impact analysis, hoping to spark new research activities that ultimately bring us a step closer to realizing wide-temperature rechargeable batteries. [ABSTRACT FROM AUTHOR]

Despite the enormous efforts to control the growth behavior of Li, achieving a dendrite‐free Li deposition and high‐energy‐density have remained an inevitable challenge of Li metal batteries. Here, the conformal deposition of Li metal is reported on electroactive organic materials to achieve a high‐energy‐density and electrochemical longevity. To this end, Li2C8H4O4 (Li2TP), which can act as both the electrode material (providing the redox capacity) and Li host (inducing the dendrite‐free Li deposition), is used as the model electroactive organic material. The Li2TP host exhibits reversible sequential lithiation/delithiation and Li deposition/stripping reactions. Consequently, a Li‐free full cell constructed by the Li2TP host (without pre‐charging) and a LiFePO4 cathode delivered a high areal capacity (≈3.8 mAh cm−2), exceptional rate performance (≤12 mA cm−2), and superior cyclability (80% capacity retention after 100 cycles). This electroactive organic material‐based Li host strategy can provide a new perspective for the development of practical Li metal batteries. [ABSTRACT FROM AUTHOR]

Current state‐of‐the‐art Li batteries use single‐phase electrolytes; however, these electrolytes often encounter difficulty in simultaneously fulfilling the nonidentical electrochemical requirements of cathodes and anodes. Here, a class of immiscible binary liquid electrolyte (BLE) is designed by starving free solvent molecules. Based on their electrochemical stability window, 1,2‐dimethoxyethane (DME) and succinonitrile (SN) are selected as model solvents for Li‐metal anodes and LiNi0.8Co0.1Mn0.1 (NCM811) cathodes, respectively. Li bis(fluorosulfonyl)imide (LiFSI), which promotes Li+ solvation (i.e., reduces free solvents), enables the phase separation of the miscible solvent mixture (SN−DME), and an increase in its concentration strengthens the coordination of Li+−FSI− in the solvation sheath, thus yielding (anion‐derived) fluorine‐rich electrode–electrolyte interphases. The resulting BLE allows 4.4 V Li‐metal full cells to exhibit a stable capacity retention under a constrained cell condition (Li (20 µm, 4.1 mAh cm−2)||NCM811 (3.8 mAh cm−2), N (negative)/P (positive) capacity ratio = 1.08), which exceed those of previously reported binary liquid electrolytes. [ABSTRACT FROM AUTHOR]

Subpleural micronodules and interlobular septal thickening are common CT scan findings in TB pleural effusion. These CT scan features could help us differentiate between TB pleural effusion and nonTB empyema. Does the frequency of subpleural micronodules and interlobular septal thickening correlate with the presence of pleural effusion in patients with pulmonary TB? CT scan findings of pulmonary TB, micronodules and their distribution (peribronchovascular, septal, subpleural, centrilobular, and random), large opacity (consolidation/macronodule), cavitation, tree-in-buds, bronchovascular bundle thickening, interlobular septal thickening, lymphadenopathy, and pleural effusion were retrospectively analyzed. Patients were divided into two groups according to the presence of pleural effusion. Clinicoradiologic findings of the two groups were then analyzed. We presented Benjamini-Hochberg critical value for multiple testing correction of CT scan findings, with a false discovery rate of 0.05. Of a total of 338 consecutive patients diagnosed with pulmonary TB who underwent CT scans, 60 were excluded because of coexisting pulmonary diseases. The frequency of subpleural nodules (47/68, 69% in pulmonary TB with pleural effusion vs 30/210, 14% in pulmonary TB without effusion, P <.001, Benjamini-Hochberg [B-H] critical value = 0.0036) and interlobular septal thickening (55/68, 81% vs 134/210, 64%, P =.009, B-H critical value = 0.0107) was significantly higher in the group of patients with pulmonary TB with pleural effusion than in the group without pleural effusion. In contrast, tree-in-buds (20/68, 29% vs 101/210, 48%, P =.007, B-H critical value = 0.0071) were less frequently seen in patients with pulmonary TB with pleural effusion. Subpleural nodules and septal thickening were more common in pulmonary TB patients with pleural effusion than in those without pleural effusion. TB involvement of the lymphatics in the peripheral interstitium could be associated with the development of pleural effusion. [ABSTRACT FROM AUTHOR]

Despite the enormous interest in high-areal-capacity Li battery electrodes, their structural instability and nonuniform charge transfer have plagued practical application. Herein, we present a cationic semi-interpenetrating polymer network (c-IPN) binder strategy, with a focus on the regulation of electrostatic phenomena in electrodes. Compared to conventional neutral linear binders, the c-IPN suppresses solvent-drying-induced crack evolution of electrodes and improves the dispersion state of electrode components owing to its surface charge-driven electrostatic repulsion and mechanical toughness. The c-IPN immobilizes anions of liquid electrolytes inside the electrodes via electrostatic attraction, thereby facilitating Li+ conduction and forming stable cathode–electrolyte interphases. Consequently, the c-IPN enables high-areal-capacity (up to 20 mAh cm–2) cathodes with decent cyclability (capacity retention after 100 cycles = 82%) using commercial slurry-cast electrode fabrication, while fully utilizing the theoretical specific capacity of LiNi0.8Co0.1Mn0.1O2. Further, coupling of the c-IPN cathodes with Li-metal anodes yields double-stacked pouch-type cells with high energy content at 25 °C (376 Wh kgcell−1/1043 Wh Lcell–1, estimated including packaging substances), demonstrating practical viability of the c-IPN binder for scalable high-areal-capacity electrodes. Binders employed in battery electrodes are conventionally neutral linear polymers. Here, authors present a cationic semi-interpenetrating polymer network binder to regulate electrostatic phenomena, improving the properties and performance of high-capacity positive electrodes for Li metal batteries. [ABSTRACT FROM AUTHOR]

Despite the enormous interest in Li metal as an ideal anode material, the uncontrollable Li dendrite growth and unstable solid electrolyte interphase have plagued its practical application. These limitations can be attributed to the sluggish and uneven Li+ migration towards Li metal surface. Here, we report olefin‐linked covalent organic frameworks (COFs) with electronegative channels for facilitating selective Li+ transport. The triazine rings and fluorinated groups of the COFs are introduced as electron‐rich sites capable of enhancing salt dissociation and guiding uniform Li+ flux within the channels, resulting in a high Li+ transference number (0.85) and high ionic conductivity (1.78 mS cm−1). The COFs are mixed with a polymeric binder to form mixed matrix membranes. These membranes enable reliable Li plating/stripping cyclability over 700 h in Li/Li symmetric cells and stable capacity retention in Li/LiFePO4 cells, demonstrating its potential as a viable cationic highway for accelerating Li+ conduction. [ABSTRACT FROM AUTHOR]

Despite the enormous interest in Li metal as an ideal anode material, the uncontrollable Li dendrite growth and unstable solid electrolyte interphase have plagued its practical application. These limitations can be attributed to the sluggish and uneven Li+ migration towards Li metal surface. Here, we report olefin‐linked covalent organic frameworks (COFs) with electronegative channels for facilitating selective Li+ transport. The triazine rings and fluorinated groups of the COFs are introduced as electron‐rich sites capable of enhancing salt dissociation and guiding uniform Li+ flux within the channels, resulting in a high Li+ transference number (0.85) and high ionic conductivity (1.78 mS cm−1). The COFs are mixed with a polymeric binder to form mixed matrix membranes. These membranes enable reliable Li plating/stripping cyclability over 700 h in Li/Li symmetric cells and stable capacity retention in Li/LiFePO4 cells, demonstrating its potential as a viable cationic highway for accelerating Li+ conduction. [ABSTRACT FROM AUTHOR]

Purpose: Studies on the effect of diabetes mellitus (DM) on the radiologic findings of pulmonary tuberculosis (PTB) have reported inconsistent results. These findings may have been influenced by the glycemic control status of the patients studied. To our knowledge, no recent data have described the effect of the DM control status on CT findings in PTB in terms of medium-sized airway involvement that is visualized as bronchial erosion on CT. The aim of this present study was to determine whether the DM control status influenced radiological manifestations in patients with PTB, with an emphasis on bronchial erosive changes. Methods: We conducted a retrospective single-center study on patients who were newly diagnosed with PTB. A total of 426 consecutive patients with PTB who underwent CT scans at the time of diagnosis from 1 January 2017 to 31 March 2020 were included in this study. The included patients were categorized as having no DM (non-DM), controlled DM, or uncontrolled DM. The patient medical charts, microbiology study results, and pulmonary changes on the CT scans were analyzed. Results: Among 426 patients with PTB who underwent CT scans at the time of diagnosis, 91 were excluded either due to undetermined hemoglobin A1C (HbA1C) levels (n = 25) or concomitant pulmonary diseases (n = 66) that would make the analysis of the pulmonary changes on CT scans difficult. Finally, 335 patients were included in this study (224 men and 111 women; mean age, 59 years; range, 16–95 years). Among the 335 patients, 82 (24.5%) had DM and 52 of those (63.4%) had an uncontrolled status. The frequency of cavitation (43% vs. 23% vs. 79%, p < 0.001) and bronchial erosion (44% vs. 30% vs. 73%, p < 0.001) was significantly different between the three groups. The uncontrolled DM group showed a high frequency of cavitation and bronchial erosion compared to the non-DM (cavitation, p < 0.001 and bronchial erosion, p < 0.001) and controlled DM groups (p < 0.001 and p < 0.001). However, the frequency of cavitation and bronchial erosion in the controlled DM group was not different compared to the non-DM group. Conclusion: The glycemic status (HbA1C ≥ 7.0), not the presence of DM, influenced the radiologic manifestations of PTB, especially in terms of medium-sized bronchial involvement, appearing as bronchial erosive changes and the feeding bronchus sign on chest CT scans. This difference in the uncontrolled DM group was likely to contribute to the higher frequency of cavitation. [ABSTRACT FROM AUTHOR]

Highlights: Mechanistic understanding of ion transport phenomena in composite solid-state electrolytes (CSEs) for practical solid-state batteries is conducted. Percolation threshold formation of the inorganic (LPSCl) phase in the CSEs depends on elasticity of the gel polymer electrolyte (GPE) phase. Manipulating the solvation/desolvation behavior of the GPE phase facilitates ion conduction across the LPSCl-GPE interfaces. Despite the enormous interest in inorganic/polymer composite solid-state electrolytes (CSEs) for solid-state batteries (SSBs), the underlying ion transport phenomena in CSEs have not yet been elucidated. Here, we address this issue by formulating a mechanistic understanding of bi-percolating ion channels formation and ion conduction across inorganic-polymer electrolyte interfaces in CSEs. A model CSE is composed of argyrodite-type Li6PS5Cl (LPSCl) and gel polymer electrolyte (GPE, including Li+-glyme complex as an ion-conducting medium). The percolation threshold of the LPSCl phase in the CSE strongly depends on the elasticity of the GPE phase. Additionally, manipulating the solvation/desolvation behavior of the Li+-glyme complex in the GPE facilitates ion conduction across the LPSCl-GPE interface. The resulting scalable CSE (area = 8 × 6 (cm × cm), thickness ~ 40 μm) can be assembled with a high-mass-loading LiNi0.7Co0.15Mn0.15O2 cathode (areal-mass-loading = 39 mg cm–2) and a graphite anode (negative (N)/positive (P) capacity ratio = 1.1) in order to fabricate an SSB full cell with bi-cell configuration. Under this constrained cell condition, the SSB full cell exhibits high volumetric energy density (480 Wh Lcell−1) and stable cyclability at 25 °C, far exceeding the values reported by previous CSE-based SSBs. [ABSTRACT FROM AUTHOR]

Despite the ever‐growing interest in micro‐supercapacitors (MSCs) as a promising power source for microelectronics, their low areal energy density has plagued practical applications. Herein, accordion foldable MSCs (af‐MSCs) are presented as a cell architectural strategy in contrast to traditional material‐driven approaches. The constituent unit cells of an in‐plane MSC array are compactly stacked in a confined device footprint via accordion folding. Decoupling the energy storage (MSC cells) and folding section (electrical interconnection between the cells) in the MSC array, in combination with neutral plane‐controlled flexible hydrophobic cellulose nanofiber (CNF) substrates, enables the realization of the af‐MSCs. The af‐MSCs achieve high areal integration density with a fill factor of 81.1% and on‐demand (in‐series/in‐parallel) cell configurations owing to the microscale direct‐ink–writing of rheology‐tuned MSC cell components on the CNF substrates. The af‐MSC with a miniaturized footprint (22.75 mm2) achieves exceptional areal electrochemical performances (areal energy density of 89.2 µWh cm−2), which exceed those of previously reported in‐plane MSCs. [ABSTRACT FROM AUTHOR]

Conventional power sources encounter difficulties in achieving structural unitization with complex‐shaped electronic devices because of their fixed form factors. Here, it is realized that an on‐demand conformal Zn‐ion battery (ZIB) on non‐developable surfaces uses direct ink writing (DIW)‐based nonplanar 3D printing. First, ZIB component (manganese oxide‐based cathode, Zn powder‐based anode, and UV‐curable gel composite electrolyte) inks are designed to regulate their colloidal interactions to fulfill the rheological requirements of nonplanar 3D printing, and establish bi‐percolating ion/electron conduction pathways, thereby enabling geometrical synchronization with non‐developable surfaces, and ensuring reliable electrochemical performance. The ZIB component inks are conformally printed on arbitrary curvilinear substrates to produce embodied ZIBs that can be seamlessly integrated with complicated 3D objects (including human ears). The conformal ZIB exhibits a high fill factor (i.e., areal coverage of cells on underlying substrates, ≈100%) that ensures high volumetric energy density (50.5 mWh cmcell−3), which exceeds those of previously‐reported shape‐adaptable power sources. [ABSTRACT FROM AUTHOR]

Challenges facing high‐voltage/high‐capacity cathodes, in addition to the longstanding problems pertinent to lithium (Li)‐metal anodes, should be addressed to develop high‐energy‐density Li‐metal batteries. This issue mostly stems from interfacial instability between electrodes and electrolytes. Conventional carbonate‐ or ether‐based liquid electrolytes suffer from not only volatility and flammability but also limited electrochemical stability window. Here, we report a nitrile electrolyte strategy based on concentrated nitrile electrolytes (CNEs) with co‐additives. The CNE consists of high‐concentration lithium bis(fluorosulfonyl)imide (LiFSI) in a solvent mixture of succinonitrile (SN)/acetonitrile (AN). The SN/AN solvent mixture is designed to ensure high oxidation stability along with thermal stability, which are prerequisites for high‐voltage Li‐metal cells. The CNE exhibits interfacial stability with Li metals due to the coordinated solvation structure. Lithium nitrate (LiNO3) and indium fluoride (InF3) are incorporated in the CNE as synergistic co‐additives to further stabilize solid‐electrolyte interphase (SEI) on Li metals. The resulting electrolyte (CNE + LiNO3/InF3) enables stable cycling performance in Li||LiNi0.8Co0.1Mn0.1 and 4.9 V‐class Li||LiNi0.5Mn1.5O4 cells. Notably, the Li||LiNi0.5Mn1.5O4 cell maintains its electrochemical activity at high temperature (100 °C) and even in flame without fire or explosion. [ABSTRACT FROM AUTHOR]

The current lithium-ion battery (LIB) electrode fabrication process relies heavily on the wet coating process, which uses the environmentally harmful and toxic N-methyl-2-pyrrolidone (NMP) solvent. In addition to being unsustainable, the use of this expensive organic solvent substantially increases the cost of battery production, as it needs to be dried and recycled throughout the manufacturing process. Herein, we report an industrially viable and sustainable dry press-coating process that uses the combination of multiwalled carbon nanotubes (MWNTs) and polyvinylidene fluoride (PVDF) as a dry powder composite and etched Al foil as a current collector. Notably, the mechanical strength and performance of the fabricated LiNi0.7Co0.1Mn0.2O2 (NCM712) dry press-coated electrodes (DPCEs) far exceed those of conventional slurry-coated electrodes (SCEs) and give rise to high loading (100 mg cm−2, 17.6 mAh cm−2) with impressive specific energy and volumetric energy density of 360 Wh kg−1 and 701 Wh L−1, respectively.Scalable dry electrode process is essential for the sustainable manufacturing of the lithium based batteries. Here, the authors propose a dry press-coating technique to fabricate a robust and flexible high loading electrode for lithium pouch cells. [ABSTRACT FROM AUTHOR]

Despite the ever‐increasing demand for transparent power sources in wireless optoelectronics, most of them have still relied on synthetic chemicals, thus limiting their versatile applications. Here, a class of transparent nanocellulose paper microsupercapacitors (TNP‐MSCs) as a beyond‐synthetic‐material strategy is demonstrated. Onto semi‐interpenetrating polymer network‐structured, thiol‐modified transparent nanocellulose paper, a thin layer of silver nanowire and a conducting polymer (chosen as a pseudocapacitive electrode material) are consecutively introduced through microscale‐patterned masks (which are fabricated by electrohydrodynamic jet printing) to produce a transparent conductive electrode (TNP‐TCE) with planar interdigitated structure. This TNP‐TCE, in combination with solid‐state gel electrolytes, enables on‐demand (in‐series/in‐parallel) cell configurations in a single body of TNP‐MSC. Driven by this structural uniqueness and scalable microfabrication, the TNP‐MSC exhibits improvements in optical transparency (T = 85%), areal capacitance (0.24 mF cm−2), controllable voltage (7.2 V per cell), and mechanical flexibility (origami airplane), which exceed those of previously reported transparent MSCs based on synthetic chemicals. [ABSTRACT FROM AUTHOR]

It has been stated that bronchial anthracofibrosis (BAF) has an important relationship with pulmonary tuberculosis (TB), and the coexistence of TB and BAF is high. The purpose of this study was to compare the differences in computed tomography (CT) characteristics of pulmonary TB according to the presence of underlying BAF. Total of 202 consecutive patients who were diagnosed with pulmonary TB and underwent bronchoscopy and CT in our institution were retrospectively reviewed. We classified the patients into two groups according to the presence of BAF and compared the clinicoradiological findings between the two groups (anthracofibrosis group vs. nonanthracofibrosis group). Elderly and female patients were significantly higher in anthracofibrosis group (mean age 79 ± 7 (64–94) vs. 56 ± 17 (16–95), p < 0.001; female 89% vs. 29%, p < 0.001). The frequency of internal low-density area or focal contour bulge within atelectasis (64% vs. 1%, p < 0.001), lower lobe predominance (43% vs. 9%, p < 0.001), endobronchial involvement (46% vs. 15%, p < 0.001), and lymphadenopathy (57% vs. 28%, p = 0.002) were significantly higher in anthracofibrosis group. In contrast, the anthracofibrosis group showed lower frequency of upper lobe predominance (32% vs. 81%, p < 0.001) and cavitation (14% vs. 51%, p = 0.001). In conclusion, being aware of these atypical manifestations of pulmonary TB in the presence of BAF will be of great help in early detection of TB. [ABSTRACT FROM AUTHOR]

Despite the extensive studies on printed power sources for user‐customized shape‐versatile electronics, most of them have still focused on printing of electrochemically active materials, with little attention to passive components such as current collectors and packaging, thus hindering their versatile application. Here, all‐direct‐ink‐writing (DIW) of artistic supercapacitors (ASCs) as a facile and scalable strategy to enable power source‐unitized monolithic electronic devices with various form factors is demonstrated. Interdigitated nickel current collectors embedded inside a polyurethane support layer are fabricated using DIW printing, which can facilitate the subsequent printing of multi‐scale, ultrathick electrodes. Interstitial voids between the DIW‐printed adjacent electrode layers are densely infiltrated by click‐crosslinkable electrolyte inks with well‐tuned rheological properties. The void‐free electrode/electrolyte assembly is conformally printed with a waterproof packaging ink to enable hermetic encapsulation, eventually producing all‐DIW‐printed ASCs with efficient space utilization, design diversity, and dimensional scalability. Notably, the resulting ASC can be seamlessly unitized with arbitrary‐shaped 3D objects (e.g., miniature pagodas), allowing for the potential development of on‐demand embodied power sources for electronic devices. [ABSTRACT FROM AUTHOR]

Despite their potential as high‐energy‐density lithium battery electrodes, Li metals are still far from practical use mainly due to their insufficient electrochemical reliability. Here, a cholesteric liquid crystalline (cLC) cellulose nanocrystal (CNC) nanomembrane as a natural material‐based mechanically robust and precisely defined ion channel strategy for sustainable Li metal electrodes is demonstrated. The cLC‐CNC nanomembrane (1 µm) is designed to achieve a self‐assembled ordered nanoporous structure with optimal tortuosity. This well‐defined cLC structure and high mechanical modulus of CNC, which are difficult to attain with traditional synthetic materials, allow facile/uniform Li‐ion flux toward Li metal electrodes, and simultaneously prevent Li dendrite growth and mitigate volume expansion of the Li metal during Li plating/stripping cycling. Driven by these viable roles of the cLC‐CNC nanomembrane, Li metal full cells (consisting of thin Li metal anodes (20 µm) and high‐capacity LiNi0.8Co0.1Mn0.1O2 (NCM811) cathodes (3.8 mAh cm–2), capacity excess of the Li metal over the NCM811 = 1.0) exhibit high energy density (890 Wh Lcell–1) along with stable cycling retention, which lie far beyond those achievable with previously reported Li protective layers. [ABSTRACT FROM AUTHOR]

Fused aromatic networks (FANs) have been studied in efforts to overcome the low physicochemical stability of metal–organic frameworks (MOFs) and covalent organic frameworks (COFs), while preserving crystallinity. Herein, we describe the synthesis of a highly stable and crystalline FAN (denoted as Pz‐FAN) using pyrazine‐based building blocks to form porphyrazine (Pz) linkages via an irreversible reaction. Unlike most COFs and FANs, which are synthesized from two different building blocks, the new Pz‐FAN is formed using a single building block by self‐cyclotetramerization. Controlled and optimized reaction conditions result in a highly crystalline Pz‐FAN with physicochemical stability. The newly prepared Pz‐FAN displayed a high magnitude (1.16×10−2 S cm−1) of proton conductivity compared to other reported FANs and polymers. Finally, the Pz‐FAN‐based membrane was evaluated for a proton‐exchange membrane fuel cell (PEMFC), which showed maximum power and current densities of 192 mW cm−2 and 481 mA cm−2, respectively. [ABSTRACT FROM AUTHOR]

Fused aromatic networks (FANs) have been studied in efforts to overcome the low physicochemical stability of metal–organic frameworks (MOFs) and covalent organic frameworks (COFs), while preserving crystallinity. Herein, we describe the synthesis of a highly stable and crystalline FAN (denoted as Pz‐FAN) using pyrazine‐based building blocks to form porphyrazine (Pz) linkages via an irreversible reaction. Unlike most COFs and FANs, which are synthesized from two different building blocks, the new Pz‐FAN is formed using a single building block by self‐cyclotetramerization. Controlled and optimized reaction conditions result in a highly crystalline Pz‐FAN with physicochemical stability. The newly prepared Pz‐FAN displayed a high magnitude (1.16×10−2 S cm−1) of proton conductivity compared to other reported FANs and polymers. Finally, the Pz‐FAN‐based membrane was evaluated for a proton‐exchange membrane fuel cell (PEMFC), which showed maximum power and current densities of 192 mW cm−2 and 481 mA cm−2, respectively. [ABSTRACT FROM AUTHOR]

Lithium metal batteries have higher theoretical energy than their Li-ion counterparts, where graphite is used at the anode. However, one of the main stumbling blocks in developing practical Li metal batteries is the lack of cathodes with high-mass-loading capable of delivering highly reversible redox reactions. To overcome this issue, here we report an electrode structure that incorporates a UV-cured non-aqueous gel electrolyte and a cathode where the LiNi0.8Co0.1Mn0.1O2 active material is contained in an electron-conductive matrix produced via simultaneous electrospinning and electrospraying. This peculiar structure prevents the solvent-drying-triggered non-uniform distribution of electrode components and shortens the time for cell aging while improving the overall redox homogeneity. Moreover, the electron-conductive matrix eliminates the use of the metal current collector. When a cathode with a mass loading of 60 mg cm−2 is coupled with a 100 µm thick Li metal electrode using additional non-aqueous fluorinated electrolyte solution in lab-scale pouch cell configuration, a specific energy and energy density of 321 Wh kg−1 and 772 Wh L−1 (based on the total mass of the cell), respectively, can be delivered in the initial cycle at 0.1 C (i.e., 1.2 mA cm−2) and 25 °C. The development of high energy lithium metal batteries is affected by the mass loading of the cathode. Here, the authors report a lithium metal pouch cell with a cathode capacity of 12 mAh cm-2. The positive electrode is prepared by applying UV-curable gel electrolyte as a processing solvent. [ABSTRACT FROM AUTHOR]

Covalent organic frameworks (COFs) have attracted considerable attention as a facile and versatile design platform for advanced energy storage materials owing to their structural diversity, ordered porous structures, and chemical stability. In this study, a redox‐active COF (TP–OH–COF) that can accommodate 30 Li+ ions is synthesized for potential use as an ultralong cyclable high‐capacity lithium‐ion battery electrode material. The TP–OH–COF is synthesized using triformylpholoroglucinol and 2,5‐diaminohydroquinone dihydrochloride under solvothermal conditions. The accommodation of such exceptional Li+ ion content in the TP–OH–COF is achieved by alternately tethering redox‐active hydroxyl and carbonyl sites on the pore walls. Owing to this unique chemical/structural feature, the TP–OH–COF delivers a high specific capacity of 764.1 mAh g–1, and capacity retention of 63% after 8000 cycles at a fast current density of 5.0 A g–1. [ABSTRACT FROM AUTHOR]

Inspired by the atomic‐sized, shape‐regulated features of G‐quadruplexes comprising guanine motifs with a monovalent metal cation, the G‐quadruplex‐forming ability, and properties of a guanine‐based π‐conjugated Y2 molecule containing bithiophene and peripheral dodecyl chain units in the presence of various cation salts (Li+, Na+, K+, and Mg2+) were exploited. A series of structural characterization revealed that Y2 yielded desirable G‐quadruplexes with all the tested cations as a consequence of the combination of a hydrogen‐bonded cyclic G‐quartet, π‐stacking, and cation‐dipole interactions. The radius and nature of the coordinating cations crucially affected the structural characteristics of G‐quadruplexes, leading to variations in the ion migration ability inside the cavity of the G‐quadruplex (Li+>Na+>K+>Mg2+), as characterized through theoretical and experimental investigations. These results not only improve the understanding of G‐quadruplex self‐assemblies based on guanine but also provide an impetus for their diverse potential applications, especially in the field of Li batteries. [ABSTRACT FROM AUTHOR]

Polymeric single lithium (Li)‐ion conductors (SICs), along with inorganic conducting materials such as sulfides and oxides, have received significant attention as promising solid‐state electrolytes. Yet their practical applications have been plagued predominantly by sluggish ion transport. Here, a new class of quasi‐solid‐state SICs based on anion‐rectifying semi‐interpenetrating polymer networks (semi‐IPNs) with reticulated ion nanochannels are demonstrated. This semi‐IPN SIC (denoted as sSIC) features a bicontinuous and nanophase‐separated linear cationic polyurethane (cPU), which supports single‐ion conducting nanochannels, and ultraviolet‐crosslinked triacrylate polymer, which serves as a mechanical framework. The cPU phase is preferentially swollen with a liquid electrolyte and subsequently allows anion‐rectifying capability and nanofluidic transport via surface charge, which enable fast Li+ migration through ion nanochannels. Such facile Li+ conduction is further enhanced by tuning ion‐pair (i.e., freely movable anions and cations tethered to the cPU chains) interaction. Notably, the resulting sSIC provides high Li+ conductivity that exceeds those of commercial carbonate liquid electrolytes. This unusual single‐ion conduction behavior of the sSIC suppresses anion‐triggered interfacial side reactions with Li‐metal anodes and facilitates electrochemical reaction kinetics at electrodes, eventually improving rate performance and cycling retention of Li‐metal cells (comprising LiNi0.8Co0.1Mn0.1O2 cathodes and Li‐metal anodes) compared to those based on carbonate liquid electrolytes. [ABSTRACT FROM AUTHOR]

In contrast to noteworthy advancements in cathode active materials for lithium‐ion batteries, the development of cathode binders has been relatively slow. This issue is more serious for high‐mass‐loading cathodes, which are preferentially used as a facile approach to enable high‐energy‐density Li‐ion batteries. Here, amphiphilic bottlebrush polymers (BBPs) are designed as a new class of cathode binder material. Using poly (acrylic acid) (PAA) as a sidechain, BBPs are synthesized through ring‐opening metathesis polymerization. The BBPs are amphiphilic in nature owing to the hydrophilic PAA sidechains and hydrophobic polynorbornene (PNB) backbones. The PNB backbone allows process compatibility with nonaqueous solvent‐based commercial cathode fabrication, while the PAA sidechain provides strong adhesion between cathode active layers and metallic current collectors. Moreover, the PAA sidechain simultaneously chelates transition metal ions dissolved from cathode active materials (LiNi0.8Mn0.1Co0.1O2 (NCM811)) particles which are chosen as a model material. Driven by the well‐balanced amphiphilicity and bottlebrush‐based structural uniqueness of the BBP binder, the resulting NCM811 cathode exhibits uniform electron/ion conduction networks and dimensional stability. Notably, a high‐mass‐loading (27 mg cm−2, corresponding to 5.2 mAh cm−2) NCM811 cathode with stable cyclability is achieved with an extremely low content (1 wt%) of the BBP binder. [ABSTRACT FROM AUTHOR]

Despite their potential as post lithium‐ion batteries, solid‐state Li‐metal batteries are struggling with insufficient electrochemical sustainability and ambient operation limitations. These challenges mainly stem from lack of reliable solid‐state electrolytes. Here, a new class of single‐ion conducting quasi‐solid‐state soft electrolyte (SICSE) for practical semi‐solid Li‐metal batteries (SSLMBs) is demonstrated. The SICSE consists of an ion‐rectifying compliant skeleton and a nonflammable coordinated electrolyte. Rheology‐tuned SICSE pastes, in combination with UV curing‐assisted multistage printing, allow fabrication of seamlessly integrated SSLMBs (composed of a Li metal anode and LiNi0.8Co0.1Mn0.1 cathode) without undergoing high‐pressure/high‐temperature manufacturing steps. The single‐ion conducting capability of the SICSE plays a viable role in stabilizing the interfaces with the electrodes. The resulting SSLMB full cell exhibits stable cycling performance and bipolar configurations with tunable voltages and high gravimetric/volumetric energy densities (476 Wh kgcell−1/1102 Wh Lcell−1 at four‐stacked cells with 16.656 V) under ambient operating conditions, along with low‐temperature performance, mechanical foldability, and nonflammability. [ABSTRACT FROM AUTHOR]

The discovery of a reliable electrolyte system remains one of the key challenges for the development of advanced lithium–oxygen batteries. To date, no single electrolyte is verified to be stable and compatible with both the cathode (e.g., oxygen radicals, lithium peroxide, etc.) and anode (lithium metal) for lithium–oxygen batteries. In this work, a novel liquid‐based Janus electrolyte system consisting of two different immiscible liquid phases is proposed and it is demonstrated that this system is remarkably effective in promoting the sustainable operation of redox‐mediated lithium–oxygen batteries. The liquid‐based Janus electrolyte is rationally designed by considering its compatibility with the lithium–oxygen cell environment, the solubility difference of target soluble species, and the mutual immiscibility of the two liquid phases. By combining spectral characterization, a phase‐separation experiment, and in situ observation of the electrochemical cell, it is revealed that the liquid‐based Janus electrolyte suppresses the migration of redox mediators from one liquid phase to the other, thereby preventing the detrimental shuttle effect. The enhanced stability of redox mediation leads to improved cycling performance of the cell. The various combinations possible for the liquid‐based Janus electrolyte open a new unexplored pathway for the design of advanced electrolyte systems for lithium–oxygen batteries. [ABSTRACT FROM AUTHOR]

Despite the enormous potential of aqueous zinc (Zn)‐ion batteries as a cost‐competitive and safer power source, their practical applications have been plagued by the chemical/electrochemical instability of Zn anodes with aqueous electrolytes. Here, ionic liquid (IL) skinny gels are reported as a new class of water‐repellent ion‐conducting protective layers customized for Zn anodes. The IL skinny gel (thickness ≈500 nm), consisting of hydrophobic IL solvent, Zn salts, and thiol‐ene polymer compliant skeleton, prevents the access of water molecules to Zn anodes while allowing Zn2+ conduction for redox reactions. The IL‐gel‐skinned Zn anode enables sustainable Zn plating/stripping cyclability under 90% depth of discharge (DODZn) without suffering from water‐triggered interfacial parasitic reactions. Driven by these advantageous effects, a Zn‐ion full cell (IL‐gel‐skinned Zn‐anode||aqueous‐electrolyte‐containing MnO2 cathode) exhibits high charge/discharge cycling performance (capacity retention ≈95.7% after 600 cycles) that lies beyond those achievable with conventional aqueous Zn‐ion battery technologies. [ABSTRACT FROM AUTHOR]

Conventional self‐charging systems are generally complicated and highly reliant on the availability of energy sources. Herein, a chemically self‐charging, flexible solid‐state zinc ion battery (ssZIB) based on a vanadium dioxide (VO2) cathode and a polyacrylamide‐chitin nanofiber (PAM‐ChNF) hydrogel electrolyte is developed. With a power density of 139.0 W kg‐1, the ssZIBs can deliver a high energy density of 231.9 Wh kg‐1. The superior electrochemical performance of the ssZIBs is attributed to the robust tunnel structure of the VO2 cathode and the entangled network of PAM‐ChNF electrolyte, which provide efficient pathways for ion diffusion. Impressively, the designed ssZIBs can be chemically self‐charged by the redox reaction between the cathode and oxygen in ambient conditions. After oxidation for 6 h in air, the ssZIBs manifest a high discharging capacity of 263.9 mAh g‐1 at 0.2 A g‐1, showing excellent self‐rechargeability. With the assistance of a small amount of acetic acid added to the hydrogel electrolyte, the galvanostatic discharging and chemical self‐charging cycles can reach 20. More importantly, such ssZIBs are able to operate well at chemical or/and galvanostatic charging hybrid modes, demonstrating superior reusability. This work brings a new prospect for designing flexible chemically self‐charging ssZIBs for portable self‐powered systems. [ABSTRACT FROM AUTHOR]

Despite extensive studies on lithium‐metal batteries (LMBs) that have garnered considerable attention as a promising high‐energy‐density system beyond current state‐of‐the‐art lithium‐ion batteries, their application to flexible power sources is staggering due to the difficulty in simultaneously achieving electrochemical sustainability and mechanical deformability. To address this issue, herein, a new electrode architecture strategy based on conductive fibrous skeletons (CFS) is proposed. Lithium is impregnated into nickel/copper‐deposited conductive poly(ethylene terephthalate) nonwovens via electrochemical plating, resulting in self‐standing CFS–Li anodes. The CFS–Li anodes exhibit stable Li plating/stripping cyclability and mechanical deformability. To achieve high‐capacity flexible cathodes, over‐lithiated layered oxide (OLO) particles are compactly embedded in conductive heteronanomats (fibrous mixtures of multiwalled carbon nanotubes and functional polymer nanofibers). The conductive heteronanomats, as CFS of OLO cathodes, provide bicontinuous electron/ion conduction pathways without heavy metallic current collectors and chelate metal ions dissolved from OLO, thus improving the areal capacity, redox kinetics, and cycling retention. Driven by the attractive characteristics of the CFS–Li anodes and CFS–OLO cathodes, the resulting CFS–LMB full cells provide improvements in the cyclability, rate performance, and more notably, (cell‐based) gravimetric/volumetric energy density (506 Wh kgcell−1/765 Wh Lcell−1) along with the exceptional mechanical flexibility. [ABSTRACT FROM AUTHOR]

Rechargeable calcium batteries have attracted increasing attention as promising multivalent ion battery systems due to the high abundance of calcium. However, the development has been hampered by the lack of suitable cathodes to accommodate the large and divalent Ca2+ ions at a high redox potential with sufficiently fast ionic conduction. Herein, we report a new intercalation host which presents 500 cycles with a capacity retention of 90% and a remarkable power capability at ~3.2 V (vs. Ca/Ca2+) in a calcium battery. The cathode material derived from Na0.5VPO4.8F0.7 is demonstrated to reversibly accommodate a large amount of Ca2+ ions, forming a series of CaxNa0.5VPO4.8F0.7 (0 < x < 0.5) phases without any noticeable structural degradation. The robust framework enables one of the smallest volume changes (1.4%) and the lowest diffusion barriers for Ca2+ among the cathodes reported to date, offering the basis for the outstanding cycle life and power capability. Rechargeable calcium batteries are promising multivalent battery systems but the lack of suitable electrodes hampers their development. Here the authors report a cathode derived from polyanion framework that demonstrates uncommonly stable and fast intercalation behaviours of calcium ions. [ABSTRACT FROM AUTHOR]

Stretchable electronics have been considered a key technology in wearable and implantable medical devices. Although substantial advances have been made in key stretchable components, a stretchable electronic platform that integrates a stretchable power source and a stretchable printed circuit board (SPCB) has been a great challenge. Here, an intrinsically stretchable electronic device platform powered by a stretchable film battery is proposed so that the platform can be used as a stand‐alone. The stretchable battery is used as a substrate for manufacturing device platforms where SPCB is printed and directly connected through via holes, thereby enabling an increase in integrated devices density. To achieve an intrinsically stretchable battery and high‐performance circuit board, a novel concept of stretchable, self‐healable, and pressure‐sensitive polymer composite is designed. The platform is water‐proof and maintains its stable electrical performance under extreme physical deformations. As a proof of concept, the integration of light‐emitting diodes on the platform that can operate at large biaxial strain (125%) underwater is demonstrated. [ABSTRACT FROM AUTHOR]

In comparison with well-protected rigid batteries with liquid electrolytes, solid-state batteries (ssBs) are more beneficial, offering high flexibility, high wearability and leakage prevention. Currently, ssBs with the capability of bending and twisting have been extensively studied. However, it remains a challenge to develop a highly stretchable ssB with the maintenance of high performance. Herein, we report a stable solid-state zinc ion battery (ssZIB) based on a cellulose nanofiber (CNF)–polyacrylamide (PAM) hydrogel electrolyte and a Mg0.23V2O5·1.0H2O cathode. The designed CNF–PAM hydrogel shows high stretchability and robust mechanical stability. Moreover, the porous CNF–PAM hydrogel electrolyte provides efficient pathways for the transportation of zinc ions. And the robust layered structure of V2O5·1.0H2O pillared with Mg2+ ions and water supports the fast insertion/extraction of zinc ions in the lattice. Therefore, the designed ssZIB shows unprecedented high capacity at high current with durable cycling life. At a current density of 5 A g−1 (charging time of around 3 minutes), the ssZIBs can deliver a high reversible capacity of 216 mA h g−1 after 2000 cycles and retain 98.6% of the initial capacity, showing a high capacity and long-life durability at high currents. Furthermore, the designed spring ssZIBs can work under stretching with the strain reaching 650%. And the designed ssZIBs are still operational even under repeated bending, freezing, and heating conditions. The ssZIBs show robust mechanical stability, high stretchability and impressive electrochemical performance, providing a potential pathway to expand the application of ZIBs to a broad range of practical energy storage devices. [ABSTRACT FROM AUTHOR]

The ever‐increasing demand for smart optoelectronics spurs the relentless pursuit of transparent wireless devices as a game‐changing technology that can provide unseen visual information behind the electronics. To enable successful operation of the transparent wireless devices, their power sources should be highly transparent in addition to acquiring reliable electrochemical performance. Among various transparent power sources, supercapacitors (SCs) have been extensively investigated as a promising candidate due to their exceptional cyclability, power capability, material diversity, and scalable/low‐cost processability. Herein, we describe current status and challenges of transparent SCs, with a focus on their core materials, performance advancements, and integration with application devices. A special attention is devoted to transparent conductive electrodes (TCEs) which act as a key‐enabling component in the transparent SCs. Based on fundamental understanding of optical theories and operating principles of transparent materials, we comprehensively discuss materials chemistry, structural design, and fabrication techniques of TCEs. In addition, noteworthy progresses of transparent SCs are briefly overviewed in terms of their architectural design, opto‐electrochemical performance, flexibility, form factors, and integration compatibility with transparent flexible/wearable devices of interest. Finally, development direction and outlook of transparent SCs are explored along with their viable roles in future application fields. [ABSTRACT FROM AUTHOR]

Coupling solar cells with energy storage devices promises to overcome issues associated with intermittency and longevity of the individual systems. Despite such significance of the coupled power sources, most previous approaches have involved bulky configurations with inactive components, eventually hindering their application as portable power sources. Furthermore, to enable practical/versatile applications of the coupled power sources, their operating voltages should be widened and customized for a specific purpose. Here, we demonstrate voltage-tunable portable power supplies based on tailored integration of interdigitated-back-contact-structured crystalline-silicon photovoltaics (cSiPV) and printed bipolar quasi-solid-state lithium-ion batteries (bQSSBs). The maximum power voltages of the cSiPVs and end-of-charge voltages of the bQSSBs are respectively varied and mutually matched to widen the operating voltage window (2.7–13.5 V) of cSiPV–bQSSB. The resulting cSiPV–bQSSB achieves high overall efficiency (10.2%) and stable photo-rechargeable cyclability. Moreover, cSiPV–bQSSB featuring a customized operating voltage is seamlessly unitized with various electronic devices and exhibits sustainable long-time operation under variable weather conditions. [ABSTRACT FROM AUTHOR]

In many catalyst systems, including fuel cell applications, control of the catalyst surface composition is important for improving activity since catalytic reactions occur only at the surface. However, it is very difficult to modify the surface composition without changing the morphology of metal nanoparticles. Herein, carbon-supported Pd3Au1 nanoparticles with uniform size and distribution are fabricated by tert-butylamine reduction method. Pd or Au surface segregation is induced by simply heating as-prepared Pd3Au1 nanoparticles under CO or Ar atmosphere, respectively. Especially, CO-induced Pd surface segregation allows the alloy nanoparticles to have a Pd-rich surface, which is attributed to the strong CO binding energy of Pd. To demonstrate the change in surface composition of Pd3Au1 alloy catalyst with the annealing gas species, the oxygen reduction reaction performance is investigated and consequently, Pd3Au1 catalyst with the highest number of surface Pd atoms indicates excellent catalytic activity. Therefore, the present work provides insights into the development of metal-based alloys with optimum structures and surface compositions for various catalytic systems. [ABSTRACT FROM AUTHOR]

Despite the ever‐growing demand for Li metals as next‐generation Li battery electrodes, little attention has been paid to their oxidation stability, which must be achieved for practical applications. Here, a new class of printable solid electrolyte interphase mimic (pSEI) for antioxidative Li metal electrodes is presented. The pSEI (≈1 µm) is directly fabricated on a thin Li metal electrode (25 µm) by processing solvent‐free, UV polymerization‐assisted printing, exhibiting its manufacturing simplicity and scalability. The pSEI is rationally designed to mimic a typical SEI comprising organic and inorganic components, in which ethoxylated trimethylolpropane triacrylate and diallyldimethylammonium bis(trifluoromethanesulfonyl)imide are introduced as an organic mimic (acting as a moisture‐repellent structural framework) and inorganic mimic (allowing facile Li‐ion transport/high Li+ transference number), respectively. Driven by the chemical/architectural uniqueness, the pSEI enables the thin Li metal electrode to show exceptional antioxidation stability and reliable full cell performance after exposure to humid environments. [ABSTRACT FROM AUTHOR]

We studied homogeneity in the microwave surface resistance of Au-coated YBa2Cu3O7−δ (Au/YBCO) films. The Au/YBCO film with 4-inches in diameter was prepared in-situ with the thicknesses of 68 nm and 365 nm for the Au layer and the YBa2Cu3O7−δ (YBCO) layer, respectively. We measured the effective surface resistance (RS,eff) of the Au/YBCO film at temperatures of 25 K, 60 K, 70 K, and 77 K, respectively, at 29 different positions on the film. The RS,eff values were analyzed with the finite thicknesses of the Au and the YBCO layers taken into consideration. The local RS,eff values of the Au/YBCO film appeared to be almost uniform at 25 K. Meanwhile significant positional dependences were observed for the RS,eff of the Au/YBCO film at 60 K, 70 K and 77 K, respectively, which seemed to be due to non-uniform local penetration depth (λ) of the YBCO layer rather than due to variations in the local real-part conductivity of the YBCO layer. The observed results could not be attributed to the properties of the Au layer. At temperatures below the critical temperature of YBCO, the observed RS,eff values of the Au/YBCO film were significantly lower than those estimated using the surface resistance of Au and YBCO, which reflected proximity effects of the normal-metal Au layer in contact with the superconducting YBCO layer. Homogeneity in the RS,eff of the Au/YBCO film might be correlated with the distributions in the local λ of the YBCO layer, providing valuable information needed for designing microwave filters. [ABSTRACT FROM AUTHOR]

Despite extensive research on flexible/wearable power sources, their structural stability and electrochemical reliability upon mechanical deformation and charge/discharge cycling have not yet been completely achieved. A new class of galvanically replaced single‐bodied lithium‐ion battery (LIB) fabric electrodes is demonstrated. As a proof of concept, metallic tin (Sn) is chosen as an electrode active material. Mechanically compliable polyethyleneterephthalate (PET) fabrics are conformally coated with thin metallic nickel (Ni) layers via electroless plating to develop flexible current collectors. Driven by the electrochemical potential difference between Ni and Sn, the thin Ni layers are galvanically replaced with Sn, resulting in the fabrication of a single‐bodied Sn@Ni fabric electrode (Sn is monolithically embedded in the Ni matrix on the PET fabric). Benefiting from the chemical/structural uniqueness and rationally designed bicontinuous ion/electron transport pathways, the single‐bodied Sn@Ni fabric electrode provides exceptional redox reaction kinetics and omnidirectional deformability (notably, origami‐folding boats), which lie far beyond those attainable with conventional LIB electrode technologies. [ABSTRACT FROM AUTHOR]

The inability to guide the nucleation locations of electrochemically deposited Li has long been considered the main factor limiting the utilization of high‐energy‐density Li‐metal batteries. In this study, an electrical conductivity gradient interfacial host comprising 1D high conductivity copper nanowires and nanocellulose insulating layers is used in stable Li‐metal anodes. The conductivity gradient system guides the nucleation sites of Li‐metal to be directed during electrochemical plating. Additionally, the controlled parameter of the intermediate layer affects the highly stable Li‐metal plating. The electrochemical behavior is confirmed through experiments associated with the COMSOL Multiphysics simulation data. The distributed Li‐ion reaction flux resulting from the controlled electrical conductivity enables stable cycling for more than 250 cycles at 1 mA cm−2. The gradient system effectively suppresses dendrite growth even at a high current density of 5 mA cm−2 and ensures Li plating and stripping with ultra‐long‐term stability. To demonstrate the high‐energy‐density full‐cell application of the developed anode, it is paired with the LiNi0.8Co0.1Mn0.1O2 cathode. The cells demonstrate a high capacity retention of 90% with an extremely high Coulombic efficiency of 99.8% over 100 cycles. These results shed light on the formidable challenges involved in exploiting the engineering aspects of high‐energy‐density Li‐metal batteries. [ABSTRACT FROM AUTHOR]

Despite their exceptionally high capacity, overlithiated layered oxides (OLO) have not yet been practically used in lithium‐ion battery cathodes due to necessary toxic/complex chemical activation processes and unsatisfactory electrochemical reliability. Here, a new class of ecofriendly chemical activation strategy based on amphiphilic deoxyribose nucleic acid (DNA)‐wrapped multiwalled carbon nanotubes (MWCNT) is demonstrated. Hydrophobic aromatic bases of DNA have a good affinity for MWCNT via noncovalent π–π stacking interactions, resulting in core (MWCNT)‐shell (DNA) hybrids (i.e., DNA@MWCNT) featuring the predominant presence of hydrophilic phosphate groups (coupled with Na+) in their outmost layers. Such spatially rearranged Na+–phosphate complexes of the DNA@MWCNT efficiently extract Li+ from monoclinic Li2MnO3 of the OLO through cation exchange reaction of Na+–Li+, thereby forming Li4Mn5O12‐type spinel nanolayers on the OLO surface. The newly formed spinel nanolayers play a crucial role in improving the structural stability of the OLO and suppressing interfacial side reactions with liquid electrolytes, eventually providing significant improvements in the charge/discharge kinetics, cyclability, and thermal stability. This beneficial effect of the DNA@MWCNT‐mediated chemical activation is comprehensively elucidated by an in‐depth structural/electrochemical characterization. [ABSTRACT FROM AUTHOR]

Lithium metal is regarded as the "Holy Grail" for rechargeable batteries yet it still suffers from low coulombic efficiency caused by its high reactivity toward the electrolyte. The so-formed solid-electrolyte interphases (SEIs) are ununiform and sluggish-ion-conducting further inducing severe dendrite growth. Herein, we report the in situ LiF-embedded covalent organic framework (COF) as a novel artificial lithium/electrolyte interphase. Briefly, an electrochemically active COF ultrathin film is synthesized by interfacial aldimine condensation, in which lithiophilic moieties reside in the high-surface-area COF film and can locally concentrate Li-salts from a dilute electrolyte. This promotes the electrochemical in situ formation of anion-derived LiF-rich SEI during the first cycling. Owing to the coaxially orientated microporous channels displayed in the COF, the as-formed LiF grains are confined in the micropores and evenly distributed throughout the COF matrix, thereby enhancing the mechanical strength of the SEI against dendrite growth as well as retaining flexibility to tolerate the anode volume change over cycling. Also, the Li+ diffusion pathway is highly ordered along the 1D pore walls of the COF so as to spatially homogenize Li+ flux. Therefore, the LiF-embedded COF interphase exhibits cooperative effectiveness to greatly stabilize the lithium metal anode. The full cell maintains its excellent performances with stable cycling and high efficiency in the close-to-practice conditions. [ABSTRACT FROM AUTHOR]

The ongoing surge in demand for flexible/wearable electronics spurs us to explore high-performance power sources with various form factors. Here we demonstrate monolithic heteronanomat (MH) paper air cathodes as a new electrode platform to enable the fabrication of origami-foldable zinc (Zn)–air batteries with reliable electrochemical rechargeability. The MH paper air cathodes consist of one-dimensional (1D) bifunctional catalyst mixtures (NdBa0.5Sr0.5Co1.5Fe0.5O5+δ double perovskite (NBSCF) nanofibers for the oxygen evolution reaction and nitrogen-doped carbon nanotubes (N-CNTs) for the oxygen reduction reaction), cellulose nanofibers (CNFs), and polytetrafluoroethylene (PTFE) nanoparticles, without the incorporation of conventional current collectors and gas diffusion layers. The CNFs and PTFE nanoparticles act as hydrophilic and hydrophobic binders, respectively, to construct three-dimensional (3D) bicontinuous electrolyte/air channels in the MH paper air cathodes. The well-developed electrolyte/air transport pathways, in combination with the rational design of the 1D bifunctional catalyst mixtures, enables the resultant Zn–air batteries (MH paper air cathode‖CNF separator membrane‖Zn–foil anode) to exhibit highly efficient charge/discharge performance and cyclability. In addition, the highly entangled network structure (based on a fibrous mixture of NBSCFs, N-CNTs, and CNFs) of the MH paper air cathode substantially improves its mechanical flexibility under various deformation modes, enabling the resultant Zn–air battery to be folded into a paper-airplane shape via origami folding. [ABSTRACT FROM AUTHOR]

The effect of the O3 feeding time on the physical and electrical properties of TiO2 thin films on Ru electrodes was investigated. The density, composition, chemical state, and crystalline structure of the TiO2 films were almost identical, irrespective of the O3 feeding time, even when the TiO2 films were grown under subsaturated conditions with respect to the O3 feeding. However, increasing the O3 feeding time to more than 3 s brought about surface roughening and severe local protrusion of the films, which significantly increased their leakage current density. The conduction band offset of the film surface was generally small and was not increased by increasing the O3 feeding time nor was the leakage current improved. Consequently, a minimum tox of 0.8 nm with a leakage current density <∼1×10-7 A/cm2 at an applied voltage of 0.8 V was achieved at an O3 feeding time of 2–3 s. [ABSTRACT FROM AUTHOR]