Reversible Copper Cathode for Nonaqueous Dual-Ion Batteries.

Most reported cathodes of nonaqueous dual-ion batteries (DIBs) host anions via insertion reactions. It is necessary to explore new cathode chemistry to increase the battery energy density. To date, transition metals have yet to be investigated for nonaqueous DIBs, albeit they may offer high capacity in anodic conversion reactions. Here, we report that bulk copper powder exhibits a high reversible capacity of 762 mAh g-1 at 3.2 V vs. Li+ /Li and relatively stable cycling in common organic electrolytes. The operation of the copper electrode is coupled with the transfer of anion charge carriers. An anion exchange membrane separator is employed to prevent Cu2+ from crossing from the catholyte to the anode side. We designed an unbalanced electrolyte with a more concentrated anolyte than a catholyte. This addresses the concentration overpotential ensued during charge and facilitates the high specific capacity and enhanced reversibility. This finding provides a promising direction for high-energy DIBs.

Copper metal electrode reversibly hosts fluoride in a 16 m KF aqueous electrolyte.

Fluoride is a promising charge carrier for batteries due to its high charge/mass ratio and small radius. Here, we report commercial copper powder exhibits a reversible capacity of up to 222 mA h g-1 in a saturated electrolyte of 16 m KF. This electrolyte suppresses dissolution of CuF2, the charged product. Furthermore, the KF solid comprised in the Cu electrode facilitates a high initial capacity. Our results showcase the potential of aqueous fluoride batteries using copper as an electrode.

From Copper to Basic Copper Carbonate: A Reversible Conversion Cathode in Aqueous Anion Batteries.

Dual-ion batteries that use anions and cations as charge carriers represent a promising energy-storage technology. However, an uncharted area is to explore transition metals as electrodes to host carbonate in conversion reactions. Here we report the reversible conversion reaction from copper to Cu2 CO3 (OH)2 , where the copper electrode comprising K2 CO3 and KOH solid is self-sufficient with anion-charge carriers. This electrode dissociates and associates K+ ions during battery charge and discharge. The copper active mass and the anion-bearing cathode exhibit a reversible capacity of 664 mAh g-1 and 299 mAh g-1 , respectively, and relatively stable cycling in a saturated mixture electrolyte of K2 CO3 and KOH. The results open an avenue to use carbonate as a charge carrier for batteries to serve for the consumption and storage of CO2 .

Saving the On-Scene Time for Out-of-Hospital Cardiac Arrest Patients: The Registered Nurses' Role and Performance in Emergency Medical Service Teams.

For out-of-hospital cardiac arrest (OHCA) patients, every second is vital for their life. Shortening the prehospital time is a challenge to emergency medical service (EMS) experts. This study focuses on the on-scene time evaluation of the registered nurses (RNs) participating in already existing EMS teams, in order to explore their role and performance in different EMS cases. In total, 1247 cases were separated into trauma and nontrauma cases. The nontrauma cases were subcategorized into OHCA (NT-O), critical (NT-C), and noncritical (NT-NC) cases, whereas the trauma cases were subcategorized into collar-and-spinal board fixation (T-CS), fracture fixation (T-F), and general trauma (T-G) cases. The average on-scene time of RN-attended cases showed a decrease of 21.05% in NT-O, 3.28% in NT-C, 0% in NT-NC, 18.44% in T-CS, 13.56% in T-F, and 3.46% in T-G compared to non-RN-attended. In NT-O and T-CS cases, the RNs' attendance can notably save the on-scene time with a statistical significance (P = .016 and .017, resp.). Furthermore, the return of spontaneous circulation within two hours (ROSC2 h) rate in the NT-O cases was increased by 12.86%. Based on the findings, the role of RNs in the EMTs could save the golden time in the prehospital medical care in Taiwan.