Aqueous rechargeable batteries are promising candidates for safe and large-scale energy storage systems, but their electrochemical performances are limited by anode degradation. Herein, poly­(2,5-dihydroxy-1,4-benzoquinone-3,6-methylene) (PDBM) is introduced as a typical benzoquinone-based anode material in an aqueous rechargeable battery. A superior higher specific capacity and longer cycling life (255 mA h g–1 and 83% capacity retention for 700 cycles at 1 C) were obtained in a mixed 1 M Li2SO4//2 M ZnSO4 electrolyte, which is better than that in a 1 M Li2SO4 (150 mA h g–1 and 76% for 700 cycles) or in a 2 M ZnSO4 electrolyte (206 mA h g–1 and 76% for 700 cycles). A defined synergistic mechanism of Li+ and Zn2+ during redox reactions is presented, in which Zn2+ ions previously occupied the out-of-plane sites with respect to the benzene rings so that the Li+ ions occupied the in-plane sites in subsequent reducing reactions. Such synergistic bonding of Li+ and Zn2+ with the polymer anode was first confirmed by density functional theory calculations and was defined as an “ion dense stacking effect”. Then, a full battery was constructed using the PDBM anode and LiMn2O4 cathode, where an average voltage of 1.15 V, an ultrahigh capacity of 228 mA h g–1 (vs anode), and a long lifespan of over 700 cycles (i.e., capacity retention, 81% at 1 C) were obtained. This is a pioneering study toward designing large-scale energy storage with a low-cost, high energy density, and ultralong life.

No abstract

ObjectiveMine rescue teams bear a high risk of injury. To improve medical emergency preparedness and injury prevention, this work analyzed the causes and severity of mine rescue teams’ casualty incidents, the primary injuries, and the link between the causes and the occurrences of the casualty incidents.MethodsA total of 81 cases from 1953 to 2013 were used to analyze the casualty incidents of mine rescue teams based on the frequency of accidents. A panel with 4 rescue experts was set up to ensure the accuracy of the analysis.ResultsThe 81 casualty incidents occurred in 7 types of rescue work and were due to 6 causes. Organizational and personal factors were the leading cause, followed by rescue skill and equipment factors. Problems with decision-making and command have gradually become the primary inducement of casualty incidents in recent years, with an average death toll reaching up to 6 to 7 people. The main injuries causing death to team members were blast injury, burns, poisoning, suffocation, blunt trauma, and overwork injury. Some of the injured died because of medical emergency response failure.ConclusionThe construction of emergency medical teams and the preparedness of disaster medicine need to be improved to reduce the mortality of the injured team members. Actions according to the causes of casualty incidents should be adopted for injury prevention. (Disaster Med Public Health Preparedness. 2019;13:695–699)

No abstract