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Lithium batteries with solid-state electrolytes are an appealing alternative to state-of-the-art non-aqueous lithium-ion batteries with liquid electrolytes because of safety and energy aspects. However, engineering development at the cell level for lithium batteries with solid-state electrolytes is limited. Here, to advance this aspect and produce high-energy lithium cells, we introduce a cell design based on advanced parametrization of microstructural and architectural parameters of electrode and electrolyte components. To validate the cell design proposed, we assemble and test (applying a stack pressure of 3.74 MPa at 45 °C) 10-layer and 4-layer solid-state lithium pouch cells with a solid polymer electrolyte, resulting in an initial specific energy of 280 Wh kg−1 (corresponding to an energy density of 600 Wh L−1) and 310 Wh kg−1 (corresponding to an energy density of 650 Wh L−1) respectively. Multiscale design principles and empirical processing techniques are considered for the design of high-energy-density Li-based batteries using polymer electrolytes. Here, the authors demonstrate the effectiveness of this approach by assembling and testing ampere-hour-level solid-state lithium-based pouch cells. [ABSTRACT FROM AUTHOR]

Electric double-layer capacitors have attracted considerable attention for energy storage because of their excellent power capability, high stability, and long cycle life. Activated carbon is the most widely employed electrode material for electric double-layer capacitors owing to its high specific surface area, hierarchical porous structure, and high electrical conductivity. However, to increase the energy density of the devices, new synthetic methods for enhancing their specific capacitances are required. We developed a facile preparation method for petroleum pitch-based activated carbon and investigated the optimal conditions to improve its electrochemical performance in terms of rate capability, specific capacitance, and cycle life. The obtained activated carbon exhibited a high specific capacitance (163.67 F/g at 0.1 A/g), which can be attributed to the efficient charge transport due to the micropores developed in the open macroporous walls of the carbon structure and the high electrical conductivity. Our approach provides an efficient strategy for synthesizing activated carbon with excellent properties. The results reveal a correlation between the physicochemical and electrochemical properties of activated carbon. [ABSTRACT FROM AUTHOR]

The ever‐increasing popularity of smart electronics demands advanced Li‐ion batteries capable of charging faster and storing more energy, which in turn stimulates the innovation of electrode additives. Developing single‐phase conductive networks featuring excellent mechanical strength/integrity coupled with efficient electron transport and durability at high‐voltage operation should maximize the rate capability and energy density, however, this has proven to be quite challenging. Herein, it is shown that a 2D titanium carbide (known as MXene) metallic membrane can be used as single‐phase interconnected conductive binder for commercial Li‐ion battery anode (i.e., Li4Ti5O12) and high‐voltage cathodes (i.e., Ni0.8Mn0.1Co0.1O2). Electrodes are fabricated directly by slurry‐casting of MXene aqueous inks composited with active materials without any other additives or solvents. The interconnected metallic MXene membrane ensures fast charge transport and provides good durability, demonstrating excellent rate performance in the Li//Li4Ti5O12 cell (90 mAh g−1 at 45 C) and high reversible capacity (154 mAh g−1 at 0.2 C/0.5 C) in Li//Ni0.8Mn0.1Co0.1O2 cell coupled with high‐voltage operation (4.3 V vs Li/Li+). The LTO//NMC full cell demonstrates promising cycling stability, maintaining capacity retention of 101.4% after 200 cycles at 4.25 V (vs Li/Li+) operation. This work provides insights into the rational design of binder‐free electrodes toward acceptable cyclability and high‐power density Li‐ion batteries. [ABSTRACT FROM AUTHOR]

Increasing the energy density of lithium‐ion batteries requires the discovery of new electrode materials capable of achieving very high areal capacity. Here, liquid phase exfoliation is used to produce nanosheets of SnP3, a 2D material with extremely high theoretical capacity of 1670 mAh g−1. These nanosheets can be fabricated into solution‐processed thin films for use as lithium storing anodes. To maximize their performance, carbon nanotubes are incorporated into the electrodes to simultaneously enhance conductivity and toughness. As a result, electrodes of thickness >300 µm can be produced, which display active‐mass‐normalized capacities (≈1657 mAh g−1Active) very close to the theoretical value. These materials show maximum specific (≈1250 mAh g−1Electrode) and areal (>20 mAh cm−2) capacities, which are at the state‐of‐the‐art for 2D‐based electrodes, coupled with good rate performance and stability. In combination with commercial cathode materials, full‐cells are fabricated with areal capacities of ≈29 mAh cm−2 and near‐record energy densities approaching 1000 Wh L−1. [ABSTRACT FROM AUTHOR]

• Encapsulated cathode composites with ionic conduction pathway were designed. • Composites were obtained by simple dry-coating strategy. • Improved rate capability and cycle stability with a facilitated ion-transport network were achieved. • Pouch cell shows excellent performance at room temperature. • Improving the stability of active materials/solid electrolyte interfaces was developed. Although solid-state batteries (SSBs) are promising next-generation energy-storage devices owing to their high safety and energy density, their wide application is hindered by critical issues such as poor power density and rapid performance degradation. These issues are related to the limit of electronic and lithium percolation networks with imperfect solid–solid interfacial contact. This study develops an optimal strategy to facilitate an ion-transport network by designing a simple core–shell–like cathode covered by an inorganic solid electrolyte (garnet-type Li 6.25 Ga 0.25 La 3 Zr 2 O 12) for polymer-based SSBs, ensuring the high capacity, high rate capability, and long-term cycle stability even in practical pouch cell at room temperature. Encapsulated cathode electrode architecture via a simple dry-coating strategy provides a percolating network for facile ionic conduction, assuring the homogeneous reaction in the cathode electrode. It alleviates not only the mechanical degradation of the cathode electrode but also the subsequent crosstalk effect on the anode–solid electrolyte interface. Our study highlights that the design of the cathode architecture considering the ion-conducting network is crucial to secure the high performance of polymer-based SSBs by maintaining the interfaces intact with solid electrolytes in both the cathode and anode interfaces. [ABSTRACT FROM AUTHOR]

Among other things, battery electrodes need to display large absolute capacities coupled with high rate performance. However, enhancing areal capacity, for example via increased electrode thickness, results in reductions in rate performance. The basis for this negative correlation has not been studied in a quantitative fashion. Here, a semiempirical model is used to analyze capacity versus rate data for electrodes fabricated from a number of materials, each measured at various thicknesses. Fitting the model to the data outputs the low‐rate areal capacity, QA, and the characteristic time associated with charge/discharge, τ, fit parameters which quantify absolute capacity and rate performance respectively. A clear correlation is found between QA and τ, with all data siting close to a mastercurve approximately defined by constant τ/QA. This data is consistent with a simple model based on the timescales associated with rate‐limiting processes. This model implies that the capacity‐rate trade‐off can be improved for high areal capacity electrodes by increasing the volumetric capacity, electrical conductivity, and porosity of the electrode. Conversely, solid‐state diffusion and reaction kinetics are only important for low areal capacity electrodes. [ABSTRACT FROM AUTHOR]