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High‐energy lithium‐ion batteries (LIBs) can be realized with the use of nickel‐rich materials, however, their reversible operation requires long‐term cathode‐electrolyte interfacial (CEI) stability, especially for high‐temperature applications, but how the CEIs evolves during operation is still a mystery. The unstable CEIs have been recently ascribed to them generating/disappearing/regenerating during Li+ extraction/insertion by in situ Fourier Transform Infrared Spectroscopy spectrum. Herein, a strategy of insoluble CEI is proposed toward addressing the interfacially induced deterioration of cathodes with a focus on Ni‐rich layered oxides. Incorporating unsaturated units (CC/CC) to siloxane as electrolyte additives advances the commercial LiNi0.8Co0.1Mn0.1O2/graphite cells up to around 300 cycles at 60 °C with more than 85% capacity retention, along with the LiCoO2 cells reaching ≈90% capacity retention over 350 cycles under 80 °C. The experimentally and theoretically detailed investigation shows that the higher unsaturation bond with high reactive sites show more polymerization via a 3D topological pathway to form insoluble CEI species, leading to suppression of parasitic reactions, corrosive acid, transition‐metal dissolution, stress corrosive cracking, and impedance growth. The scientific discoveries of this study highlight the pivotal role of electrode–electrolyte interactions and recapitulates the tried‐and‐true "electrolyte" approach for the future development of high‐energy batteries under extreme temperature conditions. [ABSTRACT FROM AUTHOR]

All‐solid‐state batteries with conversion‐type cathodes promise to exceed the performance of lithium‐ion batteries due to their high theoretical specific energy and potential safety. However, the reported performance of solid‐state batteries is still unsatisfactory due to poor electronic and ionic conduction in the composite cathodes. Here, in situ formation of active material as well as highly effective ion‐ and electron‐conducting paths via electrochemical decomposition of Li6PS5Cl0.5Br0.5 (LPSCB)/multiwalled carbon nanotube mixtures during cycling is reported. Effectively, the LPSCB electrolyte forms a multiphase conversion‐type cathode by partial decomposition during the first discharge. Comprehensive characterization, especially operando pressure monitoring, reveals a co‐redox process of two redox‐active elements during cycling. The monolithic LPSCB‐based cell shows stable cycling over 1000 cycles with a very high capacity retention of 94% at high current density (0.885 mA cm−2, ≈0.7 C) at room temperature and a high areal capacity of 12.56 mAh cm−2 is achieved. [ABSTRACT FROM AUTHOR]

Abstract: The development of lithium (Li) metal anodes Li metal batteries faces huge challenges such as uncontrolled Li dendrite growth and large volume change during Li plating/stripping, resulting in severe capacity decay and high safety hazards. A 3D porous copper (Cu) current collector as a host for Li deposition can effectively settle these problems. However, constructing a uniform and compact 3D porous Cu structure is still an enormous challenge. Herein, an electrochemical etching method for Cu–Zinc (Zn) alloy is reported to precisely engrave a 3D Cu structure with uniform, smooth, and compact porous network. Such a continuous structure endows 3D Cu excellent mechanical properties and high electrical conductivity. The uniform and smooth pores with a large internal surface area ensures well dispersed current density for homogeneous Li metal deposition and accommodation. A smooth and stable solid electrolyte interphase is formed and meanwhile Li dendrites and dead Li are effectively suppressed. The Li metal anode conceived 3D Cu current collector can stably cycle for 400 h under an Li plating/stripping capacity of 1 mA h cm−2 and a current density of 1 mA cm−2. The Li@3D Cu||LiFePO4 full cells present excellent cycling and rate performances. The electrochemical dealloying is a robust method to construct 3D Cu current collectors for dendrite‐free Li metal anodes. [ABSTRACT FROM AUTHOR]

The low Coulombic efficiency and serious security issues of lithium (Li) metal anode caused by uncontrollable Li dendrite growth have permanently prevented its practical application. A novel SiO2 hollow nanosphere-based composite solid electrolyte (SiSE) for Li metal batteries is reported. This hierarchical electrolyte is fabricated via in situ polymerizing the tripropylene gycol diacrylate (TPGDA) monomer in the presence of liquid electrolyte, which is absorbed in a SiO2 hollow nanosphere layer. The polymerized TPGDA framework keeps the prepared SiSE in a quasi-solid state without safety risks caused by electrolyte leakage, meanwhile the SiO2 layer not only acts as a mechanics-strong separator but also provides the SiSE with high room-temperature ionic conductivity (1.74 x 10-3 S cm-1) due to the high pore volume (1.49 cm³ g-1) and large liquid electrolyte uptake of SiO2 hollow nanospheres. When the SiSE is in situ fabricated on the cathode and applied to LiFePO4/SiSE/Li batteries, the obtained cells show a significant improvement in cycling stability, mainly attributed to the stable electrode/electrolyte interface and remarkable suppression for Li dendrite growth by the SiSE. This work can extend the application of hollow nanooxide and enable a safe, efficient operation of Li anode in next generation energy storage systems. [ABSTRACT FROM AUTHOR]

A hierarchical all-solid-state electrolyte based on nitrile materials (SEN) is prepared via in situ synthesis method. This hierarchical structure is fabricated by in situ polymerizing the cyanoethyl polyvinyl alcohol (PVA-CN) in succinonitrile (SN)-based solid electrolyte that is filled in the network of polyacrylonitrile (PAN)-based electrospun fiber membrane. The crosslinked PVA-CN polymer framework is uniformly dispersed in the SN-based solid electrolyte, which can strongly enhance its mechanical strength and keeps it in a quasi-solid state even over the melting point. The electrospun fiber membrane efficiently reduces the thickness of SEN film besides a further improvement in strength. Because of the unique hierarchical structure and structure similarity among the raw materials, the prepared SEN film exhibits high room-temperature ionic conductance (0.30 S), high lithium ion transference number (0.57), favorable mechanical strength (15.31 MPa), excellent safety, and good flexibility. Furthermore, the in situ synthesis ensures an excellent adhesion between SEN and electrodes, which leads to an outstanding electrochemical performance for the assembled LiFePO4/SEN/Li cells. Both the superior performance of SEN and the simple fabricating process of SEN-based all-solid-state cells make it potentially as one of the most promising electrolyte materials for next generation lithium-ion batteries. [ABSTRACT FROM AUTHOR]

Potassium Metal Batteries: Artificial Solid-Electrolyte Interphase Enabled High-Capacity and Stable Cycling Potassium Metal Batteries (Adv. The so-formed potassiophilic CNT framework with an extremely stable SEI layer alters the K deposition behavior and enables a non-dendritic growth of K metal at both ultrahigh deposition capacities and high current densities. Artificial solid-electrolyte interphase, dendrite-free deposition, potassiated carbon nanotubes, potassium metal anodes. [Extracted from the article]

Secondary batteries based on earth‐abundant potassium metal anodes are attractive for stationary energy storage. However, suppressing the formation of potassium metal dendrites during cycling is pivotal in the development of future potassium metal‐based battery technology. Herein, a promising artificial solid‐electrolyte interphase (ASEI) design, simply covering a carbon nanotube (CNT) film on the surface of a potassium metal anode, is demonstrated. The results show that the spontaneously potassiated CNT framework with a stable self‐formed solid‐electrolyte interphase layer integrates a quasi‐hosting feature with fast interfacial ion transport, which enables dendrite‐free deposition of potassium at an ultrahigh capacity (20 mAh cm−2). Remarkably, the potassium metal anode exhibits an unprecedented cycle life (over 1000 cycles, over 2000 h) at a high current density of 5 mA cm−2 and a desirable areal capacity of 4 mAh cm−2. Dendrite‐free morphology in carbon‐fiber and carbon‐black‐based ASEI for potassium metal anodes, which indicates a broader promise of this approach, is also observed. [ABSTRACT FROM AUTHOR]

Transition metal oxides hold great promise as high‐energy anodes in next‐generation lithium‐ion batteries. However, owing to the inherent limitations of low electronic/ionic conductivities and dramatic volume change during charge/discharge, it is still challenging to fabricate practically viable compacted and thick TMO anodes with satisfactory electrochemical performance. Herein, with mesoporous cobalt–boride nanoflakes serving as multifunctional bridges in ZnCo2O4 micro‐/nanospheres, a compacted ZnCo2O4/Co–B hybrid structure is constructed. Co–B nanoflakes not only bridge ZnCo2O4 nanoparticles and function as anchors for ZnCo2O4 micro‐/nanospheres to suppress the severe volume fluctuation, they also work as effective electron conduction bridges to promote fast electron transportation. More importantly, they serve as Li+ transfer bridges to provide significantly boosted Li+ diffusivity, evidenced from both experimental kinetics analysis and density functional theory calculations. The mesopores within Co–B nanoflakes help overcome the large Li+ diffusion barriers across 2D interfaces. As a result, the ZnCo2O4/Co–B electrode delivers high gravimetric/volumetric/areal capacities of 995 mAh g−1/1450 mAh cm−3/5.10 mAh cm−2, respectively, with robust rate capability and long‐term cyclability. The distinct interfacial design strategy provides a new direction for designing compacted conversion‐type anodes with superior lithium storage kinetics and stability for practical applications. A compacted Co–B/ZnCo2O4 hybrid structure is constructed with Co–B nanoflakes serving as multifunctional bridges in ZnCo2O4 micro‐/nanospheres. They not only act as robust mechanical bridges to buffer the severe volume fluctuation but also work as ionic/electronic conduction bridges to accelerate the lithium storage kinetics. Compacted and thick electrodes can be fabricated with robust rate capability and long‐term cyclability. [ABSTRACT FROM AUTHOR]

Redox active organic quinones are potentially low cost, sustainable, and high‐energy pseudocapacitive materials due to their fast and reversible redox reactivity. However, their electrically insulating nature prevents any practical application. Herein, for the first time, sodium anthraquinone‐2‐sulfonate (AQS) is examined as an organic redox‐active compound and highly conductive graphene nanosheets are incorporated to enhance the electronic conductivity. The SO3− functional group of AQS offers excellent hydrophilicity, which promotes the molecular level binding of AQS with reduced graphene oxide (rGO) and leads to a 3D interconnected xerogel (AQS@rGO). The composite exhibits a high specific capacitance of 567.1 F g−1 at 1 A g−1 with a stable capacity retention of 89.1% over 10 000 cycles at 10 A g−1. More importantly, the optimized composite maintains a high capacitance of 315.1 F g−1 even at 30 A g−1 due to the high pseudocapacitance of AQS and the capacitive contribution of rGO. First‐principles calculations further elucidate that AQS offers strong adhesion to rGO sheets with the formation of a space‐charge layer, which is favorable for the pseudocapacitance of AQS. This work opens a new avenue for developing high‐performance supercapacitors though rational combination of redox organic molecules with highly conductive graphene. Redox active organic sodium anthraquinone‐2‐sulfonate (AQS) is successfully anchored on highly conductive reduced graphene oxide sheets with the formation of a space‐charge layer, which greatly facilitates the pseudocapacitance of AQS molecules for supercapacitor applications. [ABSTRACT FROM AUTHOR]

In article number 1500353, Yan‐Bing He, Feiyu Kang, and co‐workers report the successful preparation of a hierarchical all‐solid‐state electrolyte based on nitrile materials via an in‐situ synthesis method. This electrolyte exhibits low flammability, excellent flexibility, and outstanding electrochemical performance, and has particular applications potential in wearable devices and electric vehicles. [ABSTRACT FROM AUTHOR]