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Applying high stack pressure (often up to tens of megapascals) to solid-state Li-ion batteries is primarily done to address the issues of internal voids formation and subsequent Li-ion transport blockage within the solid electrode due to volume changes. Whereas, redundant pressurizing devices lower the energy density of batteries and raise the cost. Herein, a mechanical optimization strategy involving elastic electrolyte is proposed for SSBs operating without external pressurizing, but relying solely on the built-in pressure of cells. We combine soft-rigid dual monomer copolymer with deep eutectic mixture to design an elastic solid electrolyte, which exhibits not only high stretchability and deformation recovery capability but also high room-temperature Li-ion conductivity of 2×10 −3  S cm −1 and nonflammability. The micron-sized Si anode without additional stack pressure, paired with the elastic electrolyte, exhibits exceptional stability for 300 cycles with 90.8% capacity retention. Furthermore, the solid Li/elastic electrolyte/LiFePO 4 battery delivers 143.3 mAh g −1 after 400 cycles. Finally, the micron-sized Si/elastic electrolyte/LiFePO 4 full cell operates stably for 100 cycles in the absence of any additional pressure, maintaining a capacity retention rate of 98.3%. This significantly advances the practical applications of solid-state batteries. Applying high stack pressure is primarily done to address the mechanical failure issue of solid-state batteries. Here, the authors propose a mechanical optimization strategy involving elastic electrolyte to realize solid-state batteries operating without external pressurizing.

Li–CO 2 batteries possess exceptional advantages in using greenhouse gases to provide electrical energy. However, these batteries following Li 2 CO 3 -product route usually deliver low output voltage (<2.5 V) and energy efficiency. Besides, Li 2 CO 3 -related parasitic reactions can further degrade battery performance. Herein, we introduce a soluble binuclear copper(I) complex as the liquid catalyst to achieve Li 2 C 2 O 4 products in Li–CO 2 batteries. The Li–CO 2 battery using the copper(I) complex exhibits a high electromotive voltage up to 3.38 V, an increased output voltage of 3.04 V, and an enlarged discharge capacity of 5846 mAh g −1 . And it shows robust cyclability over 400 cycles with additional help of Ru catalyst. We reveal that the copper(I) complex can easily capture CO 2 to form a bridged Cu(II)-oxalate adduct. Subsequently reduction of the adduct occurs during discharge. This work innovatively increases the output voltage of Li–CO 2 batteries to higher than 3.0 V, paving a promising avenue for the design and regulation of CO 2 conversion reactions. Li–CO 2 batteries following Li 2 CO 3 -product route suffer from low output voltage and severe parasitic reactions. Herein, a soluble binuclear copper(I) complex is introduced as the liquid catalyst to achieve Li 2 C 2 O 4 products in Li–CO 2 batteries, which increases their output voltage to higher than 3.0 V.

Reducing the high charge potential is a crucial concern in advancing the performance of lithium-oxygen batteries. Here, for water-containing lithium-oxygen batteries with lithium hydroxide products, we find that a hydrogen peroxide aqueous solution added in the electrolyte can effectively promote the decomposition of lithium hydroxide compounds at the ultralow charge potential on a catalyst-free Ketjen Black-based cathode. Furthermore, for non-aqueous lithium-oxygen batteries with lithium peroxide products, we introduce a urea hydrogen peroxide, chelating hydrogen peroxide without any water in the organic, as an electrolyte additive in lithium-oxygen batteries with a lithium metal anode and succeed in the realization of the low charge potential of ∼3.26 V, which is among the best levels reported. In addition, the undesired water generally accompanying hydrogen peroxide solutions is circumvented to protect the lithium metal anode and ensure good battery cycling stability. Our results should provide illuminating insights into approaches to enhancing lithium-oxygen batteries.

Although Li–air rechargeable batteries offer higher energy densities than lithium-ion batteries, the insulating Li2O2 formed during discharge hinders rapid, efficient re-charging. Redox mediators are used to facilitate Li2O2 oxidation; however, fast kinetics at a low charging voltage are necessary for practical applications and are yet to be achieved. We investigate the mechanism of Li2O2 oxidation by redox mediators. The rate-limiting step is the outer-sphere one-electron oxidation of Li2O2 to LiO2, which follows Marcus theory. The second step is dominated by LiO2 disproportionation, forming mostly triplet-state O2. The yield of singlet-state O2 depends on the redox potential of the mediator in a way that does not correlate with electrolyte degradation, in contrast to earlier views. Our mechanistic understanding explains why current low-voltage mediators (<+3.3 V) fail to deliver high rates (the maximum rate is at +3.74 V) and suggests important mediator design strategies to deliver sufficiently high rates for fast charging at potentials closer to the thermodynamic potential of Li2O2 oxidation (+2.96 V).Ultra-high-capacity Li–air batteries have low Coulombic efficiency and degrade during re-charging, resulting in a poor cycle life. Redox mediators enable improvements but only at undesirably high potentials. The origin of this high potential and the impact of purported reactive intermediates has now been elucidated by resolving the charging mechanism using Marcus theory.

Li-CO batteries possess exceptional advantages in using greenhouse gases to provide electrical energy. However, these batteries following Li CO -product route usually deliver low output voltage (<2.5 V) and energy efficiency. Besides, Li CO -related parasitic reactions can further degrade battery performance. Herein, we introduce a soluble binuclear copper(I) complex as the liquid catalyst to achieve Li C O products in Li-CO batteries. The Li-CO battery using the copper(I) complex exhibits a high electromotive voltage up to 3.38 V, an increased output voltage of 3.04 V, and an enlarged discharge capacity of 5846 mAh g . And it shows robust cyclability over 400 cycles with additional help of Ru catalyst. We reveal that the copper(I) complex can easily capture CO to form a bridged Cu(II)-oxalate adduct. Subsequently reduction of the adduct occurs during discharge. This work innovatively increases the output voltage of Li-CO batteries to higher than 3.0 V, paving a promising avenue for the design and regulation of CO conversion reactions.

The corrosive anions (e.g., Cl − ) have been recognized as the origins to cause severe corrosion of anode during seawater electrolysis, while in experiments it is found that natural seawater (~0.41 M Cl − ) is usually more corrosive than simulated seawater (~0.5 M Cl − ). Here we elucidate that besides Cl − , Br − in seawater is even more harmful to Ni-based anodes because of the inferior corrosion resistance and faster corrosion kinetics in bromide than in chloride. Experimental and simulated results reveal that Cl − corrodes locally to form narrow-deep pits while Br − etches extensively to generate shallow-wide pits, which can be attributed to the fast diffusion kinetics of Cl − and the lower reaction energy of Br − in the passivation layer. Additionally, for the Ni-based electrodes with catalysts (e.g., NiFe-LDH) loading on the surface, Br − causes extensive spalling of the catalyst layer, resulting in rapid performance degradation. This work clearly points out that, in addition to anti-Cl − corrosion, designing anti-Br − corrosion anodes is even more crucial for future application of seawater electrolysis. It is known that chloride anions cause severe anode corrosion during seawater electrolysis. Here we found that bromide in seawater is even more harmful to Ni-based anodes, causing the spalling of the catalyst layer and the formation of shallow-wide pits on the substrate, leading to performance degradation.

This paper focuses on the challenge of machine unlearning, aiming to remove the influence of specific training data on machine learning models. Traditionally, the development of unlearning algorithms runs parallel with that of membership inference attacks (MIA), a type of privacy threat to determine whether a data instance was used for training. However, the two strands are intimately connected: one can view machine unlearning through the lens of MIA success with respect to removed data. Recognizing this connection, we propose a game-theoretic framework that integrates MIAs into the design of unlearning algorithms. Specifically, we model the unlearning problem as a Stackelberg game in which an unlearner strives to unlearn specific training data from a model, while an auditor employs MIAs to detect the traces of the ostensibly removed data. Adopting this adversarial perspective allows the utilization of new attack advancements, facilitating the design of unlearning algorithms. Our framework stands out in two ways. First, it takes an adversarial approach and proactively incorporates the attacks into the design of unlearning algorithms. Secondly, it uses implicit differentiation to obtain the gradients that limit the attacker's success, thus benefiting the process of unlearning. We present empirical results to demonstrate the effectiveness of the proposed approach for machine unlearning.

Neonatal lipopolysaccharide (LPS) exposure can cause depressive-like behaviors in rodents involving elevated interferon (IFN)-γ. Studies have linked down-regulation of prefrontal cortex (PFC) ATPase phospholipid transporting 8A2(ATP8A2) expression to depressive-like behaviors. In non-neuronal cells, IFN-γ could reduce ATP8A2 expression. We therefore hypothesized that neonatal LPS exposure might induce PFC ATP8A2 down-regulation by increasing IFN-γ level. Here, C57BL6/J mice of both sexes received 3-dose-injections of LPS (50μg/kg bodyweight, i.p.) on postnatal day (PND)5, PND7 and PND9. LPS-treated mice showed a transiently decreased PFC ATP8A2 expression. Moreover, a negative correlation of PFC ATP8A2 expression was found with IFN-γ level. Using neutralizing mAb, IFN-γ was identified as the key mediator of LPS-induced PFC ATP8A2 decrease. Besides, neutralizing IFN-γ during neonatal LPS exposure attenuated the depressive-like behaviors in adulthood. In sum, neonatal LPS exposure reduced ATP8A2 level in PFC in mice via increasing IFN-γ level, maybe associated with mechanism underlying LPS-induced brain and behavior impairments.