Ageing of magnesium /manganese dioxide primary cells

Abstract

Mg/MnO 2 primary cells which were more than a decade old were investigated for their discharge capacity, a.c. impedance behaviour, delay time, eect of added water into the cell and eect of temperature. Although the cells were aged for a long duration, they were electrochemically active and yielded good discharge capacity, thus suggesting an extraordinary long shelf-life. There was a marginal increase in cell capacity subsequent to injection of 2 ml of water into a CD-size Mg/ MnO 2 cell. The a.c. impedance of a partially discharged cell included the contributions of surface passive ®lm on the Mg anode and corrosion of the Mg metal. The internal resistance of the cell was found to increase with storage time, suggesting that the resistance of a fresh cell also could similarly increase. By increasing the cell temperature, the impedance decreased considerably and also the delay time. These results suggested that the increase of temperature had favourable eects on the performance of the aged Mg/MnO 2 cells. Key words Magnesium/manganese dioxide cell á Ageing á Delay time á Temperature eect á A.c. impedance

Strategies to Enable Reversible Magnesium Electrochemistry: From Electrolytes to Artificial Solid–Electrolyte Interphases

“…Thec oncept of Mg-ion batteries was first reported at the beginning of the 20 th century,i nt he context of ap rimary battery.C hlorides (e.g., AgCl, [14] CuCl, PbCl 2 , [15] and PdCl 2 ), Cu 2 I 2 ,C uSCN, MnO 2 , [16] and air [17] have been used as cathode materials and Mg-based alloys used as anodes,while aqueous solutions such as sea water or magnesium perchlorate aqueous solution have been used as the electrolytes. [18,19] Compared to lithium alloys,m agnesium alloys are relatively stable in aqueous electrolytes,t hus enabling the commercialization of primary Mg-ion batteries.F or example,aAgCl/Mg/water-activated battery was first commercially available in 1943, [20] and aMgair/NaCl-H 2 Of uel cell was commercialized by General Electric in the early 1960s.…”

The Effects of NaHCO3on the Voltage Delay of Mg Cell with AZ31B Magnesium Alloy in Mg(ClO4)2Electrolytic Solution

“…2,3 Compared with the conventional Leclanche cells, viz. zinc/manganese dioxide (Zn/MnO 2 ) primary batteries, known for their acceptable performance characteristics for a large number of applications, low cost and ready availability, 4 magnesium/manganese dioxide (Mg/MnO 2 ) batteries possess several outstanding advantages, such as higher shelf life, good capacity retention and high thermal stability, which double the battery capacity. 5 However, there are several bottlenecks limiting the development of Mg primary battery.…”

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“…However, relative to these batteries, magnesium/manganese dioxide (Mg/MnO 2 ) primary batteries are superior because of their high cell voltage, high energy densities per unit weight/volume at high power densities and low discharge temperatures, and long shelf life at ambient and extremely high temperatures. [6][7][8][9][10] Even so, Mg/MnO 2 primary batteries are currently not widely applied. Mg/MnO 2 primary batteries are limited in anodic efficiency by the relatively low corrosion resistance of magnesium toward various aqueous electrolytes.…”