Postconsumer plastics are generally perceived as valueless with only a small portion of plastic waste being closed-loop recycled into similar products while most of them are discarded in landfills. Depositing plastic waste in landfills not only harms the environment but also signifies a substantial economic loss. Alternatively, constructing value-added chemical feedstocks via mining the waste-derived intermediate species as a carbon (C) source under mild electrochemical conditions is a sustainable strategy to realize the circular economy. This proof-of-concept work provides an attractive "turning trash to treasure" strategy by integrating electrocatalytic polyethylene terephthalate (PET) plastic upcycling with a chemical C-S coupling reaction to synthesize organosulfur compounds, hydroxymethanesulfonate (HMS). HMS can be produced efficiently (Faradaic efficiency, FE of ∼70%) via deliberately capturing electrophilic intermediates generated in the PET monomer (ethylene glycol, EG) upcycling process, followed by coupling them with nucleophilic sulfur (S) species (i.e., SO₃^2- and HSO₃^-). Unlike many previous studies conducted under alkaline conditions, PET upcycling was performed over an amorphous MnO₂ catalyst under near-neutral conditions, allowing for the stabilization of electrophilic intermediates. The compatibility of this strategy was further investigated by employing biomass-derived compounds as substrates. Moreover, comparable HMS yields can be achieved with real-world PET plastics, showing its enormous potential in practical application. Lastly, Density function theory (DFT) calculation reveals that the C-C cleavage step of EG is the rate-determining step (RDS), and amorphous MnO₂ significantly decreases the energy barriers for both RDS and C-S coupling when compared to the crystalline counterpart.

LiFePO₄ (LFP) batteries are well known for their long cycle life. However, there are many reports of significant capacity degradation in LFP battery packs after only three to five years of operation. This study assesses the second-life potential of commercial LFP batteries retired from electric vehicles (EVs) by evaluating their aging characteristics at the cell and module levels. Four LFP cells and four modules were subjected to aging tests under various conditions. The results indicate that LFP cells exhibit long life cycles with gradual capacity degradation and a minimal internal resistance increase. Module-level analysis reveals significant balance issues impacting capacity recovery. Incremental capacity analysis (ICA) and post-mortem analysis identify the loss of active materials and lithium inventory as key aging mechanisms. This study provides the optimal working conditions of second-life LFP batteries and suggests that, with proper balancing systems, LFP batteries can achieve extended second-life use in stationary energy storage applications, emphasizing the importance of effective balance management for sustainable battery utilization.

Transforming and repurposing plastic waste into valuable commodity chemical products is a sustainable strategy, which is beneficial for not only managing plastic waste but also fostering a circular plastic economy. Herein, we reported an electrocatalytic polyethylene terephthalate (PET) plastic waste upcycling to organonitrogen chemicals strategy over a MnO₂ (MnO₂/CFP) catalyst. The MnO₂/CFP catalyst is capable of mildly oxidizing PET plastic-waste-derived ethylene glycol (EG) to electrophilic carbon intermediates under near-neutral conditions, in which the in situ formed carbon intermediates were stabilized and further attacked by nitrogenous nucleophiles, leading to the successful formation of amides. As a result, formamide (FE and yield up to 10.86% and 0.030 mmol cm^-2 h^-1, respectively) was produced as the primary C-N coupling product with EG and ammonia (NH₃) as C and N sources, respectively. Furthermore, amides were synthesized with real-world PET plastic waste as the C source, indicating the potential practical application of this proof-of-concept work.