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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]

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]

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]

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]

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]

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]

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]

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]

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]

Abstract: Electronic garments have garnered considerable attention as a core technology for the upcoming wearable electronics era. To enable ubiquitous operation of electronic garments, they must be monolithically integrated with rechargeable power sources. Here, inspired by printing‐assisted aesthetic clothing designs, a new class of wearable supercapacitors (SCs) is demonstrated that can be directly printed on T‐shirts, which look like letters (or symbols) commonly printed on T‐shirts. The printed SCs consist of activated carbon/multiwalled carbon nanotube/ionic liquid‐based electrodes and ionic liquid/thiol‐ene polymer network skeleton/SiO2 nanoparticle‐based gel electrolytes. The rheological properties of the electrode/electrolyte pastes are fine‐tuned by varying the colloidal network structure, which affects the printing processability and formation of the nanoscale ion/electron conduction channels. To ensure the seamless unitization and design versatility of the printed SCs, the T‐shirt is sewn with electroconductive stainless steel (SS) threads prior to the printing process. Onto the SS threads acting as shape‐directing current collectors, the electrode/electrolyte pastes are sequentially stencil‐printed and sealed with water‐proof packaging films. The printed SCs exhibit exceptional form factors, flexibility, and thermal stability. Notably, the SC‐printed T‐shirts maintain their electrochemical activity upon exposure to laundering, wringing, ironing, and folding, demonstrating their potential and practical applicability as a promising electronic garment technology. [ABSTRACT FROM AUTHOR]

The ongoing surge in demand for high-energy/flexible rechargeable batteries relentlessly drives technological innovations in cell architecture as well as electrochemically active materials. Here, a new class of all-nanomat lithium-ion batteries (LIBs) based on 1D building element-interweaved heteronanomat skeletons is demonstrated. Among various electrode materials, silicon (Si, for anode) and overlithiated layered oxide (OLO, for cathode) materials are chosen as model systems to explore feasibility of this new cell architecture and achieve unprecedented cell capacity. Nanomat electrodes, which are completely different from conventional slurry-cast electrodes, are fabricated through concurrent electrospinning (for polymeric nanofibers) and electrospraying (for electrode materials/carbon nanotubes (CNTs)). Si (or rambutan-shaped OLO/CNT composite) powders are compactly embedded in the spatially interweaved polymeric nanofiber/CNT heteromat skeletons that play a crucial role in constructing 3D-bicontinuous ion/electron transport pathways and allow for removal of metallic foil current collectors. The nanomat Si anodes and nanomat OLO cathodes are assembled with nanomat Al2O3 separators, leading to the fabrication of all-nanomat LIB full cells. Driven by the aforementioned structural/chemical uniqueness, the all-nanomat full cell shows exceptional improvement in electrochemical performance (notably, cell-based gravimetric energy density = 479 W h kgCell−1) and also mechanical deformability, which lie far beyond those achievable with conventional LIB technologies. [ABSTRACT FROM AUTHOR]

In this study, thermoplastic polyurethane (TPU) and ethylene propylene diene terpolymer (EPDM) were melt-mixed with multi walled carbon nanotube (MWCNT), respectively. The change in the surface resistivity of the nanocomposites during annealing at room temperature was examined. The surface resistivity of TPU/MWCNT nanocomposites with 3 and 5 phr MWCNT and uncrosslinked EPDM/MWCNT nanocomposites with 4 and 6 phr MWCNT significantly increases with increasing annealing time at room temperature. To delay the increase of surface resistivity during annealing at room temperature, silica was added to the TPU/MWCNT and EPDM/MWCNT nanocomposites. The rate of increase in the surface resistivity during annealing at room temperature was much slower with addition of silica to the nanocomposites. POLYM. COMPOS., 38:E525-E530, 2017. © 2016 Society of Plastics Engineers [ABSTRACT FROM AUTHOR]

Battery separators are supposed to be electrical insulators to prevent internal short-circuit failure between electrodes as well as having porous channels to allow ion transport. Here, as a multifunctional membrane strategy to dispel this stereotypical belief about battery separators, a new class of Janus-faced, dual (ion/electron)-conductive/chemically active battery separators (denoted as 'Janus separators') based on a heterolayered nanofiber mat architecture is demonstrated. The Janus separator, which is fabricated through in-series, concurrent electrospraying/electrospinning processes, consists of an ion-conductive/metal ion-chelating support layer (a mat of densely packed, thiol-functionalized silica particles spatially besieged by polyvinylpyrrolidone/polyacrylonitrile nanofibers) and a dual-conductive top layer (a thin mat of polyetherimide nanofibers wrapped with multi-walled carbon nanotubes). The support layer acts as a chemical trap that can capture heavy metal ions dissolved in liquid electrolytes and the top layer serves as an upper current collector for cathodes to boost the redox reaction kinetics. Notably, the unusual porous microstructure of the top layer is theoretically elucidated using molecular dynamics simulation. Benefiting from such material/structural uniqueness, the Janus separator enables significant improvements in fast-rate charge/discharge reactions (even for high-mass loading cathodes) and in the high-temperature cycling performance, which lie far beyond those achievable with conventional polyethylene separators. [ABSTRACT FROM AUTHOR]

Acquisition of high-energy density is the highest priority requirement and unending challenge in energy storage systems including lithium-ion batteries (LIBs). One theoretically preferable way to reach this goal is the use of cathode active materials such as vanadium pentoxide (V2O5) that relies on multielectron insertion/extraction reactions. Application of V2O5 to LIB cathodes, however, has been mostly focused on V2O5 materials themselves with little emphasis on V2O5-incorporated cathode sheets. Here, as an unusual electrode-architecture approach to achieve ultrahigh-capacity V2O5 cathode sheets, a new class of self-standing V2O5 cathode sheets is demonstrated based on V2O5/multiwalled carbon tubes (MWNTs) mixtures spatially besieged by polyacrylonitrile nanofibers (referred to as 'VMP cathode sheets'). Notably, the VMP cathode sheet is fabricated directly via one-pot synthetic route starting from V2O5 precursor (i.e., through concurrent electrospraying/electrospinning followed by calcination), without metallic foil current collectors/carbon powders/polymeric binders. The one-pot synthesis allows dense packing of V2O5 nanoparticles in close contact with MWNT electronic networks and also formation of well-developed interstitial void channels (ensuring good electrolyte accessibility). This material/architecture uniqueness of the VMP cathode sheet eventually enables significant improvements in cell performance (particularly, gravimetric/volumetric capacity of cathode sheets) far beyond those accessible with conventional electrode technologies. [ABSTRACT FROM AUTHOR]

Surface modification of electrode active materials has garnered considerable attention as a facile way to meet stringent requirements of advanced lithium-ion batteries. Here, we demonstrated a new coating strategy based on dual layers comprising antimony-doped tin oxide (ATO) nanoparticles and carbon. The ATO nanoparticles are synthesized via a hydrothermal method and act as electronically conductive/electrochemically active materials. The as-synthesized ATO nanoparticles are introduced on natural graphite along with citric acid used as a carbon precursor. After carbonization, the carbon/ATO-decorated natural graphite (c/ATO-NG) is produced. In the (carbon/ATO) dual-layer coating, the ATO nanoparticles coupled with the carbon layer exhibit unprecedented synergistic effects. The resultant c/ATO-NG anode materials display significant improvements in capacity (530 mA h g−1), cycling retention (capacity retention of 98.1 % after 50 cycles at a rate of C/5), and low electrode swelling (volume expansion of 38 % after 100 cycles) which outperform that of typical graphite materials. Furthermore, a full-cell consisting of a c/ATO-NG anode and an LiNi0.5Mn1.5O4 cathode presents excellent cycle retention (capacity retention of >80 % after 100 cycles). We envision that the dual-layer coating concept proposed herein opens a new route toward high-performance anode materials for lithium-ion batteries. [ABSTRACT FROM AUTHOR]

The cathode active particles‐embedded polyacrylonitrile nanofibers/multiwalled carbon nanotubes heteronanomat cathode (HM cathode) is demonstrated as an effective and versatile electrode platform to address the long‐standing challenges of conventional cathodes. The material/structure uniqueness of the HM cathode enables substantial improvements in rate capability, cycling performance and, most notably, areal capacity far beyond those accessible with conventional cathode technologies. [ABSTRACT FROM AUTHOR]

The superlattice crystals–mimic, flexible/functional ceramic membrane is presented as a new ceramic‐driven material/architecture opportunity for next‐generation high‐performance battery separators. The structural uniqueness/Mn2+‐chelating ability of the ceramic membrane (comprising the close‐packed, thiol groups–containing silica particles spatially besieged by the polyvinylpyrrolidone/polyacrylonitrile nanofiber skeleton) enables unprecedented improvement in the membrane properties and, more notably, the high‐temperature cyclability far beyond those accessible with conventional polymeric separators. [ABSTRACT FROM AUTHOR]

The excellent stability of sulfide solid electrolytes with solvate ionic liquids Li(triethylene glycol dimethyl ether)bis(trifluoromethanesulfonyl)imide (Li(G3)TFSI), and their application for high‐performance, all‐solid‐state lithium‐ion batteries are successfully demonstrated. The addition of a small amount of Li(G3)TFSI gives an alternative ionic pathway through normally poor solid–solid contacts, leading to a dramatic increase in LiFePO4 composite electrode capacity. [ABSTRACT FROM AUTHOR]

Forthcoming smart energy era is in strong pursuit of full-fledged rechargeable power sources with reliable electrochemical performances and shape versatility. Here, as a naturally abundant/environmentally friendly cellulose-mediated cell architecture strategy to address this challenging issue, a new class of hetero-nanonet (HN) paper batteries based on 1D building blocks of cellulose nanofibrils (CNFs)/multiwall carbon nanotubes (MWNTs) is demonstrated. The HN paper batteries consist of CNF/MWNT-intermingled heteronets embracing electrode active powders (CM electrodes) and microporous CNF separator membranes. The CNF/MWNT heteronet-mediated material/structural uniqueness enables the construction of 3D bicontinuous electron/ion transport pathways in the CM electrodes, thus facilitating electrochemical reaction kinetics. Furthermore, the metallic current collectors-free, CNF/MWNT heteronet architecture allows multiple stacking of CM electrodes in series, eventually leading to user-tailored, ultrathick (i.e., high-mass loading) electrodes far beyond those accessible with conventional battery technologies. Notably, the HN battery (multistacked LiNi0.5Mn1.5O4 (cathode)/multistacked graphite (anode)) provides exceptionally high-energy density (=226 Wh kg−1 per cell at 400 W kg−1 per cell), which surpasses the target value (=200 Wh kg−1 at 400 W kg−1) of long-range (=300 miles) electric vehicle batteries. In addition, the heteronet-enabled mechanical compliance of CM electrodes, in combination with readily deformable CNF separators, allows the fabrication of paper crane batteries via origami folding technique. [ABSTRACT FROM AUTHOR]

A composite separator membrane (CSM) with an A/B/A type layered structure, composed of a microporous electrolyte-philic poly(vinylidene fluoride- co-hexafluoropropylene) (PVdF-HFP) gel layer (A) and a submicrometer porous polyethylene (PE) or a macroporous poly(ethylene terephthalate) (PET) non-woven matrix (B), is introduced in a dye-sensitized solar cell (DSSC). Commercially available PE and PET separator membranes (SMs) act as matrices that provide mechanical stability to the DSSC and permanent pore structures for facilitated ion transport. PVdF-HFP is used as a microporous gelator for improved interfacial contact between the solid SM and the electrodes. The PVdF-HFP gel impedes the charge recombination process between electron and I3 − at the TiO2/electrolyte interface, resulting in improved electron lifetimes. The DSSC assembled with the CSM exhibits high initial solar energy conversion efficiency ( η, 6.1%) and stable η values over 1400 h, demonstrating good long term stability. The behaviors of the DSSC are attributed to the synergistic factors of the CSM, such as improved ion conductivity, electrolyte affinity, electrolyte retention capability, effective interfacial contact, and plausible passivation of the dyes. This study demonstrates a practical combination of short- and long-term DSSC performance through the introduction of the CSM. [ABSTRACT FROM AUTHOR]

The combination of high-capacity anodes and high-voltage cathodes has garnered a great deal of attention in the pursuit of high-energy-density lithium-ion batteries. As a facile and scalable electrode-architecture strategy to achieve this goal, a direct one-pot decoration of high-capacity silicon (Si) anode materials and of high-voltage LiCoO2 (LCO) cathode materials is demonstrated with colloidal nanoparticles composed of electroconductive antimony-doped tin oxide (ATO). The unusual ATO nanoparticle shells enhance electronic conduction in the LCO and Si electrode materials and mitigate unwanted interfacial side reactions between the electrode materials and liquid electrolytes. The ATO-coated LCO materials (ATO-LCO) enable the construction of a high-mass-loading cathode and suppress the dissolution of cobalt and the generation of by-products during high-voltage cycling. In addition, the ATO-coated Si (ATO-Si) anodes exhibit highly stable capacity retention upon cycling. Integration of the high-voltage ATO-LCO cathode and high-capacity ATO-Si anode into a full cell configuration brings unprecedented improvements in the volumetric energy density and in the cycling performance compared to a commercialized cell system composed of LCO/graphite. [ABSTRACT FROM AUTHOR]

A new class of highly thin, deformable, and safety-reinforced plastic crystal polymer electrolytes (N-PCPEs) is demonstrated as an innovative solid electrolyte for potential use in high-performance flexible lithium-ion batteries with aesthetic versatility and robust safety. The unusual N-PCPEs are fabricated by combining a plastic crystal polymer electrolyte with a porous polyethylene terephthalate (PET) nonwoven. Herein, the three-dimensional reticulated plastic crystal polymer electrolyte matrix is formed directly inside the PET nonwoven skeleton via in-situ UV-crosslinking of ethoxylated trimethylolpropane triacrylate (ETPTA) monomer, under co-presence of plastic crystal electrolyte. The PET nonwoven is incorporated as a compliant skeleton to enhance mechanical/dimensional strength of N-PCPE. Owing to this structural uniqueness, the N-PCPE shows significant improvements in the film thickness and deformability with maintaining advantageous features (such as high ionic conductivity and thermal stability) of the PCE. Based on structural/physicochemical characterization of N-PCPE, its potential application as a solid electrolyte for flexible lithium-ion batteries is explored by scrutinizing the electrochemical performance of cells. The high ionic conductance of N-PCPE, along with its excellent deformability, plays a viable role in improving cell performance (particularly at high current densities and also mechanically deformed states). Notably, the cell assembled with N-PCPE exhibits stable electrochemical performance even under a severely wrinkled state, without suffering from internal short-circuit failures between electrodes. [ABSTRACT FROM AUTHOR]

Conductive fibrous skeletons, flexibility, lithium-metal full cells, OLO cathodes, ultrahigh energy density Conductive Fibrous Skeletons: Ultrahigh-Energy-Density Flexible Lithium-Metal Full Cells based on Conductive Fibrous Skeletons (Adv. Keywords: conductive fibrous skeletons; flexibility; lithium-metal full cells; OLO cathodes; ultrahigh energy density EN conductive fibrous skeletons flexibility lithium-metal full cells OLO cathodes ultrahigh energy density 1 1 1 06/26/21 20210624 NES 210624 In article number 2100531, Young-Gi Lee, Sang-Young Lee and co-workers present conductive fibrous skeletons (CFS) as a new electrode architecture strategy for ultrahigh-energy-density flexible lithium-metal battery (LMB) full cells. [Extracted from the article]

Discusses laminar morphology development and oxygen permeability of low density polyethylene/ethylene-vinyl alcohol copolymer blends. Viscosity ratio of the components; Processing conditions; Compatibilizer level; Oxygen permeation tests; Explanation of the correlation between morphology and oxygen permeability.