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Sulfide electrolyte all-solid-state lithium batteries (ASLBs) with uncoated Li-NixMnyCo1−x−yO2(NMC) cathodes suffer from a large capacity loss during initial cycling and an increase in cell impedance. Decomposition reactions are known to occur at the Li6PS5Cl-NMC111 interface due to incompatibility between the two materials. If a stabilizing coating is applied to the NMC, it delivers full capacity during initial charge. However, the loss in capacity during discharge still occurs. The interface was studied byμXANES and through EIS analysis. A chemically-formed interphase was detected byμXANES, evident from reduction of Co at an uncoated NMC particle surface. This interphase was produced by decomposition at rest. To study the effect of the interphase on electrochemically active surface area, piecewise in situ EIS was performed and the data was modeled using a transmission line model (TLM). The charge transfer resistance RCTwas used to estimate the volume specific active surface area (aact). The median value for aactwas 296 cm−1, a factor of 7.5 lower than the theoretical value of 2216 cm−1. This provided evidence of a lower electrochemically active surface area in the ASLB.more » « less
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Abstract Non‐native plants are typically released from specialist enemies but continue to be attacked by generalists, albeit at lower intensities. This reduced herbivory may lead to less investment in constitutive defences and greater investment in induced defences, potentially reducing defence costs. We compared herbivory on 27 non‐native and 59 native species in the field and conducted bioassays and chemical analyses on 12 pairs of non‐native and native congeners. Non‐natives suffered less damage and had weaker constitutive defences, but stronger induced defences than natives. For non‐natives, the strength of constitutive defences was correlated with the intensity of herbivory experienced, whereas induced defences showed the reverse. Investment in induced defences correlated positively with growth, suggesting a novel mechanism for the evolution of increased competitive ability. To our knowledge, these are the first linkages reported among trade‐offs in plant defences related to the intensity of herbivory, allocation to constitutive versus induced defences, and growth.more » « less
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Abstract Due to its outstanding safety and high energy density, all‐solid‐state lithium‐sulfur batteries (ASLSBs) are considered as a potential future energy storage technology. The electrochemical reaction pathway in ASLSBs with inorganic solid‐state electrolytes is different from Li‐S batteries with liquid electrolytes, but the mechanism remains unclear. By combining operando Raman spectroscopy and ex situ X‐ray absorption spectroscopy, we investigated the reaction mechanism of sulfur (S8) in ASLSBs. Our results revealed that no Li2S8,Li2S6,and Li2S4were formed, yet Li2S2was detected. Furthermore, first‐principles structural calculations were employed to disclose the formation energy of solid state Li2Sn(1≤n≤8), in which Li2S2was a metastable phase, consistent with experimental observations. Meanwhile, partial S8and Li2S2remained at the full lithiation stage, suggesting incomplete reaction due to sluggish reaction kinetics in ASLSBs.more » « less
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Abstract The application of hardware‐based neural networks can be enhanced by integrating sensory neurons and synapses that enable direct input from external stimuli. This work reports direct optical control of an oscillatory neuron based on volatile threshold switching in V3O5. The devices exhibit electroforming‐free operation with switching parameters that can be tuned by optical illumination. Using temperature‐dependent electrical measurements, conductive atomic force microscopy (C‐AFM), in situ thermal imaging, and lumped element modelling, it is shown that the changes in switching parameters, including threshold and hold voltages, arise from overall conductivity increase of the oxide film due to the contribution of both photoconductive and bolometric characteristics of V3O5, which eventually affects the oscillation dynamics. Furthermore, V3O5is identified as a new bolometric material with a temperature coefficient of resistance (TCR) as high as −4.6% K−1at 423 K. The utility of these devices is illustrated by demonstrating in‐sensor reservoir computing with reduced computational effort and an optical encoding layer for spiking neural network (SNN), respectively, using a simulated array of devices.more » « less
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