Reductive Dissolution of NCM Cathode through Anaerobic Respiration by Shewanella putrefaciens.

The consumption of lithium-ion batteries (LIBs) has considerably increased over the past decade, leading to a rapid increase in the number of spent LIBs. Exposing spent LIBs to the environment can cause serious environmental harm; however, there is a lack of experimentally obtained information regarding the environmental impacts of abandoned cathode materials. Here, we report the interactions between Shewanella putrefaciens, a microorganism commonly found in diverse low-oxygen natural settings, and LiNi0.6Co0.2Mn0.2O2 (NCM622) under anaerobic conditions. We present compelling evidence that the anaerobic respiration of Shewanella putrefaciens triggers ∼59 and ∼78% dissolution of 0.2 g/L pristine and spent NCM622, respectively. We observed that Shewanella putrefaciens interacted with the pristine and the spent NCM622 under anaerobic conditions at a neutral pH and room temperature and induced the reduction of Ni, Co, and Mn, resulting in the subsequent dissolution of Li, Ni, Co, and Mn. Moreover, we found that secondary mineralization occurred on the surface of reacted NCM622. These findings not only shed light on the substantial impact of microbial respiration on the fate of discarded cathode materials in anaerobic environments but also reveal the potential for sustainable bioleaching of cathodes in spent LIBs.

Ultrafast Metaphotonic PCR Chip with Near-Perfect Absorber.

Polymerase chain reaction (PCR) is the gold standard for nucleic acid amplification and quantification in diverse fields such as life sciences, global health, medicine, agricultural science, forensic science, and environmental science for global sustainability. However, implementing a cost-effective PCR remains challenging for rapid preventive medical action to the widespread pandemic diseases due to the absence of highly efficient and low-cost PCR chip-based POC molecular diagnostics. Here, this work reports an ultrafast metaphotonic PCR chip as a solution of a cost-effective and low-power-consumption POC device for the emerging global challenge of sustainable healthcare. This work designs a near-perfect photonic meta-absorber using ring-shaped titanium nitride to maximize the photothermal effect and realize rapid heating and cooling cycles during the PCR process. This work fabricates a large-area photonic meta-absorber on a 6-inch wafer cost-effectively using simple colloidal lithography. In addition, this work demonstrates 30 thermocycles from 65 (annealing temperature) to 95 °C (denaturation temperature) within 3 min 15 s, achieving an average 16.66 °C s-1 heating rate and 7.77 °C s-1 cooling rate during thermocycling, succeeding rapid metaphotonic PCR. This work believes a metaphotonic PCR chip can be used to create a low-cost, ultrafast molecular diagnostic chip with a meta-absorber.

Mobile Efficient Diagnostics of Infectious Diseases via On-Chip RT-qPCR: MEDIC-PCR.

The COVID-19 outbreak has caused public and global health crises. However, the lack of on-site fast, reliable, sensitive, and low-cost reverse transcription polymerase chain reaction (RT-PCR) testing limits early detection, timely isolation, and epidemic prevention and control. Here, the authors report a rapid mobile efficient diagnostics of infectious diseases via on-chip -RT-quantitative PCR (RT-qPCR): MEDIC-PCR. First, the authors use a roll-to-roll printing process to accomplish low-cost carbon-black-based disposable PCR chips that enable rapid LED-induced photothermal PCR cycles. The MEDIC-PCR can perform RT (3 min), and PCR (9 min) steps. Further, the cohort of 89 COVID-19 and 103 non-COVID-19 patients testing is completed by the MEDIC-PCR to show excellent diagnostic accuracy of 97%, sensitivity of 94%, and specificity of 98%. This MEDIC-PCR can contribute to the preventive global health in the face of a future pandemic.