No abstract

An ammonium chloride roasting approach can convert lithium metal oxides to water-soluble lithium and transition metal chlorides at 300 °C, promising an energy-efficient and environmentally benign way to recover end-of-life lithium-ion batteries. Unlike conventional chlorination processes, the roasting of LiCoO2 using NH4Cl as both reducing and chlorination agents is complex, and thus more efforts such as thermodynamics and the underlying mechanism are required to be understood. This paper aims to study the chlorination process by comprehensive thermodynamic analysis and a variety of control experiments such as operating temperature, gas atmosphere, NH4Cl/LiCoO2 mass ratios, and the way of mixing feedstocks. It is found that the chlorination of LiCoO2 is governed by a solid-to-solid reaction mechanism based on thermodynamics, thermal analysis, and roasting products. Finally, the regenerated LiCoO2 delivers a specific capacity of over 139.8 mAh g–1 at 0.5C with a capacity retention rate of 99% after 100 cycles. Overall, the chlorination process can be engineered by adjusting the temperatures, pressure, and contact area between NH4Cl and LiCoO2 to further reduce the energy consumption and thereby increase the utilization of NH4Cl and chlorination efficiencies.

No abstract

Desirable biosensing assays need to be sensitive, specific, cost‐effective, instrument‐free, and versatile. Herein we report a new strategy termed CLIPON (CRISPR and Large DNA assembly Induced Pregnancy strips for signal‐ON detection) that can deliver these traits. CLIPON integrates a commercial pregnancy test strip (PTS) with four biological elements: the human chorionic gonadotropin (hCG), CRISPR‐Cas12a, crRNA and cauliflower‐like large‐sized DNA assemblies (CLD). CLIPON uses the Cas12a/crRNA complex both to recognize a target of interest and to release CLD‐bound hCG so that target presence can translate into a colorimetric signal on the PTS. We demonstrate the versatility of CLIPON through sensitive and specific detection of HPV genomic DNA, SARS‐CoV‐2 genomic RNA and adenosine. We also engineer a cell phone app and a hand‐held microchip to achieve signal quantification. CLIPON represents an attractive option for biosensing and point‐of‐care diagnostics.