MONOLITHIC LITHIUM/SULFUR- POLY(ACRYLONITRILE) COMPOSITE-BASED BATTERIES: SYNTHESIS AND STRUCTURE- RELATED ELECTROCHEMISTRY

摘要

The viability of any battery-based concept strongly depends on a few issues which are - apart from the price - (i) safety of the device, (ii) high energy density and (iii) good cycling stability. A promising combination of elements for the next generation of batteries is lithium/sulfur. 1,2 However, in view of the experimental status of all other alternatives, this does not mean that there are no further challenges and issues to be solved. The theoretical specific capacity of elemental sulfur for S + 2e~- → S~(2-) is 1672 mA. h/g, which is the highest of any solid cathode material. Together with lithium (2 Li → 2 Li ~+ + 2e~- ), the theoretical specific energy density of the entire battery amounts to approx. 2,600 Wh/kg. However, in view of their status quo, both the energy density and cycle stability of Li/S battery systems still has to be essentially improved. Thus, current energy densities of Li/S batteries are in the range of 300-550 W· h/kg_(battery). In order to do so, its chemistry and physics need to be fully understood.