Wetting of the liquid metal on the solid electrolyte of a liquid metal battery controls the operating temperature and performance of the battery. Liquid sodium electrodes are particularly attractive because of their low cost, natural abundance, and geological distribution. However, they wet poorly on a solid electrolyte near its melting temperature, limiting their widespread suitability for low-temperature batteries to be used for large-scale energy storage systems. Herein, we develop an isolated metal-island strategy that can improve sodium wetting in sodium-beta alumina batteries that allows operation at lower temperatures. Our results suggest that in situ heat treatment of a solid electrolyte followed by bismuth deposition effectively eliminates oxygen and moisture from the surface of the solid electrolyte, preventing the formation of an oxide layer on the liquid sodium, leading to enhanced wetting. We also show that employing isolated bismuth islands significantly improves cell performance, with cells retaining 94% of their charge after the initial cycle, an improvement over cells without bismuth islands. These results suggest that coating isolated metal islands is a promising and straightforward strategy for the development of low-temperature sodium-β alumina batteries.

Controlling ion transport in nanofluidics is fundamental to water purification, bio-sensing, energy storage, energy conversion, and numerous other applications. For any of these, it is essential to design nanofluidic channels that are stable in the liquid phase and enable specific ions to pass. A human neuron is one such system, where electrical signals are transmitted by cation transport for high-speed communication related to neuromorphic computing. Here, we present a concept of neuro-inspired energy harvesting that uses confined van der Waals crystal and demonstrate a method to maximise the ion diffusion flux to generate an electromotive force. The confined nanochannel is robust in liquids as in neuron cells, enabling steady-state ion diffusion for hundred of hours and exhibiting ion selectivity of 95.8%, energy conversion efficiency of 41.4%, and power density of 5.26 W/m2. This fundamental understanding and rational design strategy can enable previously unrealisable applications of passive-type large-scale power generation.

Photolithography is the prevalent microfabrication technology. It needs to meet resolution and yield demands at a cost that makes it economically viable. However, conventional farfield photolithography has reached the diffraction limit, which imposes complex optics and short-wavelength beam source to achieve high resolution at the expense of cost efficiency. Here, we present a cost-effective near-field optical printing approach that uses metal patterns embedded in a flexible elastomer photomask with mechanical robustness. This technique generates sub-diffraction patterns that are smaller than 1/10 th of the wavelength of the incoming light. It can be integrated into existing hardware and standard mercury lamp, and used for a variety of surfaces, such as curved, rough and defect surfaces. This method offers a higher resolution than common light-based printing systems, while enabling parallel-writing. We anticipate that it will be widely used in academic and industrial productions.

Rationale: The systemic inflammatory milieu plays an important role in the age-related decline in functional integrity, but its contribution to age-related disease (e.g., stroke) remains largely unknown. Objective: To determine the role of systemic inflammatory milieu in ischemic stroke. Methods and Results: Here, we report that systemic administration of serum exosomes from young rats (Y-exo) into aged ischemic rats improved short- and long-term functional outcomes after ischemic stroke and reduced synaptic loss. By contract, similar injections of serum exosomes from aged rats (O-exo) into aged ischemic rats worsened sensorimotor deficits through exacerbation of synaptic dysfunction due to excessive microglial phagoptosis (primary phagocytosis). Our proteomic analysis further revealed that the expression of CD46, a C3b/C4b-inactivating factor, was higher in Y-exo, compared to O-exo. Whereas the prevalence of pro-inflammatory mediators (C1q, C3a and C3b) in serum exosomes increased with age. Microglial expression of C3a/b and C3aR increased after O-exo treatment, compared with Y-exo and vehicle groups. Administration of a selective C3aR inhibitor or microglial depletion attenuated synaptic dysfunction associated with O-exo treatment and improved post-stroke functional recovery. Conclusions: Our data suggest that the levels of pro-inflammatory mediators in serum exosomes increase with age and are associated with worsened stroke outcomes through excessive C3aR-dependent microglial phagoptosis. Modulation of this process may serve as a promising therapy for stroke and other age-related brain disorders.

The decomposition, electron transfer, and protonation of oxygen molecules are typically assumed to be the rate-limiting steps of the oxygen reduction reactions (ORR), and the activation energy barriers of these reactions can be surmounted using catalysts. In this study, the physical rate-limiting step of the ORR consists of the adsorption of gaseous oxygen molecules at the liquid-solid phase boundary, indicating that the formation of a gas-liquidsolid triple-phase boundary (TPB) is important for accelerating the ORR kinetics. This is experimentally confirmed by analyzing the ORR in aluminum-air batteries. Moreover, the formation of a TPB using the hierarchical pores of sparked reduced graphene oxide is demonstrated, which serve as the cathode, and the remarkable electrochemical performance of the fabricated battery is presented. These findings can be used to accelerate the ORR kinetics by maximizing the TPB, particularly in aluminum-air batteries.