Ab initio study of mechanical strength of solid polymer electrolyte (PEO)5LiClO4

Mechanical strength is one of the significant properties of any solid polymer electrolyte of electrochemical devices, therefore; the ab initio study based on density functional theory is performed, and the bond strength of Poly ethylene oxide (PEO) 5 polymer without and with Lithium Perchlorate (LiClO 4 ) is investigated. The central oxygen atom of PEO is displaced till to respective bond is broken along X, Y, and Z directions, respectively. The same is simulated in the presence of LiClO 4 and the minimum bond breaking energy which is also called the mechanical strength is calculated along three directions. Higher energy is required in compression of (PEO) 5 along x and y axes than expansion, and vice versa along z axis. The same is observed for (PEO) 5 -LiClO 4 polymer electrolyte along x and y axes, along z direction; the energy required is nearly same for compression/expansion. Due to this energy, crystalline nature of a polymer is reduced and amorphous nature is increased. In DOS analysis, the forbidden energy gap of (PEO) 5 -LiClO 4 is reduced by 1.0 eV than (PEO) 5 ; it causes to increase the lithium cation concentration and the ionic conductivity.