Self-corrosion, electrochemical and discharge behavior of commercial purity Al anode via Mn modification in Al-air battery

The self-corrosion, electrochemical and discharge behavior of commercial purity Al anode via Mn modification in Al-air battery was studied by the hydrogen evolution, weight loss, electrical conductivity, electrochemical and discharge tests. Results show that the synergetic effects of the dissolved Mn and Mn-modifying Al_(3)Fe intermetallic decrease the weight loss and inhibit the hydrogen evolution of commercial purity Al in Na OH solution when minor Mn is introduced. However, more Mn addition leads to the formation of Al_6Mn intermetallic,which has little effect on the weight loss, but accelerates the hydrogen evolution. Mn introduction plays a positive role in activating Al anodes, resulting in a decrease in the anodic polarization and an increase in the discharge voltage. Among all the commercial purity Al-x Mn anodes, 0.1 wt% Mn addition exhibits the best discharge efficiency for Al-air battery.

TIME AND POLING HISTORY DEPENDENT ENERGY STORAGE AND DISCHARGE BEHAVIORS IN POLY(VINYLIDENE FLUORIDE-CO-HEXAFLUOROPROPYLENE) RANDOM COPOLYMERS

We studied cycle time （0.01-10 s with triangular input waves） and poling history （continuous versus fresh poling） dependent electric energy storage and discharge behaviors in poly（vinylidene fluoride-co-hexafluoropropylene） [P（VDF- HFP）] films using the electric displacement -- the electric field （D-E） hysteresis loop measurements. Since the permanent dipoles in PVDF are orientational in nature, it is generally considered that both charging and discharging processes should be time and poling history dependent. Intriguingly, our experimental results showed that the charging process depended heavily on the cycle time and the prior poling history, and thus the D-E hysteresis loops had different shapes accordingly. However, the discharged energy density did not change no matter how the D-E loop shape varied due to different measurements. This experimental result could be explained in terms of reversible and irreversible polarizations. The reversible polarization could be charged and discharged fairly quickly （〈 5 ms for each process）, while the irreversible polarization depended heavily on the poling time and the prior poling history. This study suggests that it is only meaningful to compare the discharged energy density for PVDF and its copolymer films when different cycle times and poling histories are used.

High-temperature liquid Sn-air energy storage cell

A new type of a high temperature liquid metal-air energy storage cell based on solid oxide electrolyte has been successfully demonstrated at 750 ℃ by feeding metal Sn. In order to understanding the initial size effect of metal as a liquid fuel, we report here the impact of the thermal and electrochemical oxidation behavior of nano Sn （-100 nm）, comparing with micro-sized （-5 μm） and macro-sized （4350 μm） Sn. The thermogravimetric analysis and the monitoring OCV test indicate that the distinct property of nano-sized Sn results in a favorable thermal oxidation behavior near the melting point and a promising power performance due to enhanced fuel transport to the anode. However, the accumulated Sn oxide at the reaction interface during a discharge test towards the limitation of further electrochemical oxidation.