A simple methodology for the quantification of graphite in end-of-life lithium-ion batteries using thermogravimetric analysis.

A new method based on thermogravimetric analysis was developed to measure the graphite content in battery material mixture. This approach exploits the thermochemical reduction of cathodic Li-transition metal oxides with anodic graphite at elevated temperatures under an inert atmosphere. Using known composition artificial mixtures, a linear correlation between cathode mass loss and sample graphite content was observed. The method was validated using industrial black mass samples and characterized traditionally to estimate and rationalize potential error sources. Thermal degradation profiles of industrial battery waste reflected those in the artificial system, demonstrating its applicability. This work also demonstrates that thermogravimetric degradation profiles can distinguish between a cathode consisting of single or multiple Li-metal oxides. Although accuracy depends on active component mixture content and impurities, it is demonstrated that the method is useful for a fast graphite content estimation. Unlike other graphite characterization techniques, the method proposed is simple and inexpensive.

Impact of hospital and emergency department structural and organizational characteristics on outcomes of acute heart failure.

INTRODUCTION AND OBJECTIVES: To determine whether structural/organizational characteristics of hospitals and emergency departments (EDs) affect acute heart failure (AHF) outcomes. METHODS: We performed a secondary analysis of the EAHFE Registry. Six hospital/ED characteristics were collected and were related to 7 postindex events and postdischarge outcomes, adjusted by the period of patient inclusion, baseline patient characteristics, AHF episode features, and hospital and ED characteristics. The relationship between discharge directly from the ED (DDED) and outcomes was assessed, and interaction was analyzed according to the hospital/ED characteristics. RESULTS: We analyzed 17 974 AHF episodes included by 40 Spanish EDs. Prolonged stays were less frequent in high-technology hospitals and those with hospitalization at home and with high-inflow EDs, and were more frequent in hospitals with a heart failure unit (HFU) and an ED observation unit. In-hospital mortality was lower in high-technology hospitals (OR, 0.78; 95%CI, 0.65-0.94). Analysis of 30-day postdischarge outcomes showed that hospitals with a short-stay unit (SSU) had higher hospitalization rates (OR, 1.19; 95%CI, 1.02-1.38), high-inflow EDs had lower mortality (OR, 0.73; 95%CI, 0.56-0.96) and fewer combined events (OR, 0.87; 95%CI, 0.76-0.99), while hospitals with HFU had fewer ED reconsultations (OR, 0.83; 95%CI, 0.76-0.91), hospitalizations (OR, 0.85; 95%CI, 0.75-0.97), and combined events (OR, 0.84; 95%CI, 0.77-0.92). The higher the percentage of DDED, the fewer the prolonged stays. Among other interactions, we found that more frequent DDED was associated with more 30-day postdischarge reconsultations, hospitalizations and combined events in hospitals without SSUs, but not in hospitals with an SSU. CONCLUSIONS: AHF outcomes were significantly affected by the structural/organizational characteristics of hospitals and EDs and their aggressiveness in ED management.