Search

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]

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]

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]