Upcycling of spent LiCoO_(2) cathodes via nickel- and manganese-doping

Direct recycling has been regarded as one of the most promising approaches to dealing with the increasing amount of spent lithium‐ion batteries(LIBs).However,the current direct recycling method remains insufficient to regenerate outdated cathodes to meet current industry needs as it only aims at recovering the structure and composition of degraded cathodes.Herein,a nickel(Ni)and manganese(Mn)co‐doping strategy has been adopted to enhance LiCoO_(2)(LCO)cathode for next‐generation high‐performance LIBs through a conventional hydrothermal treatment combined with short annealing approach.Unlike direct recycling methods that make no changes to the chemical composition of cathodes,the unique upcycling process fabricates a series of cathodes doped with different contents of Ni and Mn.The regenerated LCO cathode with 5%doping delivers excellent electrochemical performance with a discharge capacity of 160.23 mAh g^(−1) at 1.0 C and capacity retention of 91.2%after 100 cycles,considerably surpassing those of the pristine one(124.05 mAh g^(−1) and 89.05%).All results indicate the feasibility of such Ni–Mn co‐doping‐enabled upcycling on regenerating LCO cathodes.

Designing gradient solid electrolyte interphase for stable lithium metal batteries

The practical application of lithium metal batteries(LMBs)has been impeded by the unstable electrolyte interphase and uncontrollable Li dendrites growth.The structures and components of solid electrolyte interphase(SEI)are extremely important to affect the electrochemical performance of LMBs,but it is hard to regulate them due to the complicated reaction mechanisms.Therein,a gradient SEI layer was designed by adding bisfluoroacetamide into electrolyte,which could guide the uniform deposition of Li ions and suppress the growth of Li dendrites.In addition,this additive also could improve the stability of cathode,resulting in a stable LMBs.

Natural long-chain saturated fatty acids doped LNPs enabling spleen selective mRNA translation and potent cancer immunotherapy

Rationally tailored lipid nanoparticles(LNPs)with efficient and tunable delivery of mRNA in vivo are crucial for mRNA vaccines.Selective expression of antigenic protein in lymphoid tissues/organs could improve the immunostimulatory efficacy and safety of LNPs-based mRNA vaccines.Inspired by the metabolic behavior that long-chain saturated fatty acids tending to enter lymphoid tissue rather than the liver,we developed fatty acid-doped LNPs capable of mediating differential protein expressions in the liver and spleen when administered intravenously.When the molar ratio of saturated fatty acid located 60%–70%,the doped LNPs achieved the spleen selective mRNA translation.The mechanism could be attributed to the different cellular uptake behaviors of saturated fatty acids in hepatocytes.Immunization with a model antigen(ovalbumin)mRNA-loaded spleen selective LNPs,we observed enhanced antigen-specific T cell immune responses,and potent immunotherapeutic and immunoprophylactic efficacy in the mouse lymphoma model.Our natural long-chain saturated fatty acids metabolic characteristics-inspired design of LNPs for spleen-selective mRNA vaccines delivery will provide references for designing mRNA vaccines with high efficacy and safety for tumor immunotherapy.

3D Hierarchical Carbon‑Rich Micro‑/Nanomaterials for Energy Storage and Catalysis

Increasing concerns over climate change and energy shortage have driven the development of clean energy devices such as batteries,supercapacitors,fuel cells and solar water splitting in the past decades.And among potential device materials,3D hierarchical carbon-rich micro-/nanomaterials(3D HCMNs)have come under intense scrutiny because they can prevent the stacking and bundling of low-dimensional building blocks to not only shorten diffusion distances for matter and charge to achieve high-energy-high-power storage but also greatly expose active sites to achieve highly active,durable and efficient catalysis.Based on this,this review will summarize the synthetic strategies and formation mechanisms of 3D HCMNs,including 3D nanocarbons,polymers,COFs/MOFs,templated carbons and derived carbon-based hybrids with a focus on 3D superstructures such as urchins,flowers,hierarchical tubular structures as well as nanoarrays including nanotube,nanofiber and nanosheet arrays.This review will also discuss the application of 3D HCMNs in energy storage and catalysis systems,including batteries,supercapacitors,electrocatalysis and photo(electro)catalysis.Overall,this review will provide a comprehensive overview of the recent progress of 3D HCMNs in terms of preparation strategies,formation mechanisms,structural diversities and electrochemical applications to provide a guideline for the rational design and structure–function exploration of 3D hierarchical nanomaterials from different sources beyond carbon-based species.

Real-time measurements of PM_(2.5),PM_(10-2.5),and BC in an urban street canyon

A continuous dichotomous beta gauge monitor was used to characterize the hourly content of PM2.5, PM10-2.5, and Black Carbon （BC） over a 12-month period in an urban street canyon of Hong Kong. Hourly vehicle counts for nine vehicle classes and meteorological data were also recorded. The average weekly cycles of PM2.5, PM10-2.5, and BC suggested that all species are related to traffic, with high concentrations on workdays and low concentrations over the weekends. PM2.s exhibited two comparable concentrations at 10：00-11：00 （63.4 μg/m3） and 17：00-18：00 （65.0 p.g/m3 ） local time （LT） during workdays, correspond- ing to the hours when the numbers of diesel-fueled and gasoline-fueled vehicles were at their maximum levels： 3179 and 2907 h-1, respectively. BC is emitted mainly by diesel-fueled vehicles and this showed the highest concentration （31.2μg/m3） during the midday period （10：00-11：00 LT） on workdays. A poor correlation was found between PM2.s concentration and wind speed （R= 0.51, P-value 〉 0.001 ）. In contrast, the concentration of PM10-2.s was found to depend upon wind speed and it increased with obvious statistical significance as wind speed increased （R = 0,98, P-value 〈 0.0001 ）.