Ni3 S2 -Ni Hybrid Nanospheres with Intra-Core Void Structure Encapsulated in N-Doped Carbon Shells for Efficient and Stable K-ion Storage

Dynamic Induction of Conversion-Based Anode Degradation by Valence State and Mechanical Cracks

Electrochemical energy storage through conversion reactions in crystalline electrode materials primarily depends on the size of guest ions. In this study, a combination of synchrotron-based transmission X-ray microscopy and X-ray absorption near edge spectroscopy is utilized to reveal the dynamic physicochemical changes in the micro-regions of spherical NiS2 active particles during the potassiation/depotassiation process. The findings show that, as the degree of potassiation increases, visible cracks and voids form within the bulk material, with significant differences in the chemical valence states of metal elements between the inner and outer regions. Furthermore, the voids induce the formation of new cracks, which propagate extensively into the bulk, serving as the root cause of electrode particle failure. Based on these observations, it is also demonstrated that this failure phenomenon in active materials can be mitigated through dimensional engineering strategies, paving the way for the development of high-capacity and highly stable potassium-ion batteries.

Nitrogen-Doped Porous Nanofiber Aerogel-Encapsulated Staphylo-Ni3S2 Accelerating Polysulfide Conversion for Efficient Li-S Batteries

The low conductivity of sulfur substances and the fussy effect of lithium polysulfides (LPS) limit the practical application of lithium-sulfur batteries (LSBs). In this work, Ni3S2 is in situ synthesized on N-doped 3D carbon nanofibers with an optimized pore structure as a cathode material for LSBs. The conductive carbon nanofiber skeleton with a hierarchical (micropore-mesopore-macropore) structure etched by Cd2+ can reduce the interface resistance of the cathode and remiss volume expansion during charge-discharge progress. The Ni was vulcanized and nitrogen-doped successively during the annealing process. In addition, the polar Ni3S2 and N-doped carbon structure can promote the catalytic conversion of LPS and regulate the 3D nucleation of Li2S, which could reduce the reaction energy barrier. Therefore, the NCF-Cd-Ni3S2-NC cathode can maintain a high initial capacity (1080.2 mAh g-1) and excellent stability at 0.1C. This work provides an important basis for the synthesis of high efficiency and inexpensive cathode carrier materials for LSBs.

Carbon encapsulated nanoparticles: materials science and energy applications

The technological implementation of electrochemical energy conversion and storage necessitates the acquisition of high-performance electrocatalysts and electrodes. Carbon encapsulated nanoparticles have emerged as an exciting option owing to their unique advantages that strike a high-level activity-stability balance. Ever-growing attention to this unique type of material is partly attributed to the straightforward rationale of carbonizing ubiquitous organic species under energetic conditions. In addition, on-demand precursors pave the way for not only introducing dopants and surface functional groups into the carbon shell but also generating diverse metal-based nanoparticle cores. By controlling the synthetic parameters, both the carbon shell and the metallic core are facilely engineered in terms of structure, composition, and dimensions. Apart from multiple easy-to-understand superiorities, such as improved agglomeration, corrosion, oxidation, and pulverization resistance and charge conduction, afforded by the carbon encapsulation, potential core-shell synergistic interactions lead to the fine-tuning of the electronic structures of both components. These features collectively contribute to the emerging energy applications of these nanostructures as novel electrocatalysts and electrodes. Thus, a systematic and comprehensive review is urgently needed to summarize recent advancements and stimulate further efforts in this rapidly evolving research field.

NIR triggered polydopamine coated cerium dioxide nanozyme for ameliorating acute lung injury via enhanced ROS scavenging

Acute lung injury (ALI) is a life threatening disease in critically ill patients, and characterized by excessive reactive oxygen species (ROS) and inflammatory factors levels in the lung. Multiple evidences suggest that nanozyme with diversified catalytic capabilities plays a vital role in this fatal lung injury. At present, we developed a novel class of polydopamine (PDA) coated cerium dioxide (CeO2) nanozyme (Ce@P) that acts as the potent ROS scavenger for scavenging intracellular ROS and suppressing inflammatory responses against ALI. Herein, we aimed to identify that Ce@P combining with NIR irradiation could further strengthen its ROS scavenging capacity. Specifically, NIR triggered Ce@P exhibited the most potent antioxidant and anti-inflammatory behaviors in lipopolysaccharide (LPS) induced macrophages through decreasing the intracellular ROS levels, down-regulating the levels of TNF-α, IL-1β and IL-6, up-regulating the level of antioxidant cytokine (SOD-2), inducing M2 directional polarization (CD206 up-regulation), and increasing the expression level of HSP70. Besides, we performed intravenous (IV) injection of Ce@P in LPS induced ALI rat model, and found that it significantly accumulated in the lung tissue for 6 h after injection. It was also observed that Ce@P + NIR presented the superior behaviors of decreasing lung inflammation, alleviating diffuse alveolar damage, as well as promoting lung tissue repair. All in all, it has developed the strategy of using Ce@P combining with NIR irradiation for the synergistic enhanced treatment of ALI, which can serve as a promising therapeutic strategy for the clinical treatment of ROS derived diseases as well.

Mesoporous Nickel Sulfide Microsphere Encapsulated in Nitrogen, Sulfur Dual-Doped Carbon with Large Subsurface Region for Enhanced Sodium Storage

Nickel sulfides are promising anode candidates in sodium ion batteries (SIBs) due to high capacity and abundant reserves. However, their applications are restricted by poor cycling stability and slow reaction kinetics. Thus, mesoporous nickel sulfide microsphere encapsulated in nitrogen, sulfur dual-doped carbon (MNS@NSC) is prepared. The packaged structure and carbon matrix restrain the volume variation together, the N, S dual-doping improves the electronic conductivity and offers extra active sites for sodium storage. Ex-situ X-ray diffraction  appeals copper collector adsorbs polysulfide to inhibit the polysulfide accumulation and enhance conductivity. Moreover, the large subsurface attributed to C-S-S-C bonding further boosts pseudocapacitive capacity, conducive to charge transfer. As a result, MNS@NSC delivers a high reversible capacity of 640.2 mAh g-1 after 100 cycles at 0.1 A g-1, an excellent rate capability (569.8 mAh g-1 at 5 A g-1), and a remained capacity of 513.8 mAh g-1 after undergoing 10000 circulations at 10 A g-1. The MNS@NSC|| Na3V2(PO4)3 full cell shows a cycling performance of specific capacity of 230.8 mAh g-1 after 100 cycles at 1 A g-1. This work puts forward a valid strategy of combing structural design and heteroatom doping to synthesize high-performance nickel sulfide materials in SIBs.

Dual-Functional Z-Scheme TiO2 @MoS2 @NC Multi-Heterostructures for Photo-Driving Ultrafast Sodium Ion Storage

Exploiting dual-functional photoelectrodes to harvest and store solar energy is a challenging but efficient way for achieving renewable energy utilization. Herein, multi-heterostructures consisting of N-doped carbon coated MoS2 nanosheets supported by tubular TiO2 with photoelectric conversion and electronic transfer interfaces are designed. When a photo sodium ion battery (photo-SIB) is assembled based on the heterostructures, its capacity increases to 399.3 mAh g-1 with a high photo-conversion efficiency of 0.71 % switching from dark to visible light at 2.0 A g-1 . Remarkably, the photo-SIB can be recharged by light only, with a striking capacity of 231.4 mAh g-1 . Experimental and theoretical results suggest that the proposed multi-heterostructures can enhance charge transfer kinetics, maintain structural stability, and facilitate the separation of photo-excited carriers. This work presents a new strategy to design dual-functional photoelectrodes for efficient use of solar energy.