Lithium/sodium-selenium (Li/Na-Se) batteries are promising energy storage systems due to their relatively low cost and high volumetric energy density of Se cathode. Rechargeable lithium-ion batteries (LIBs) play a critical role in portable devices, electric vehicles and large-scale stationary energy storage, due to their relatively high energy density and low cost among available technologies. Sodium-selenium (Na-Se) batteries have also drawn much attention, because of the large abundance and low cost of sodium and decent energy density of Se. As a cathode material, Se provides a moderate gravimetric capacity of 678 mAh g~(-1), a high volumetric capacity of 3270 mAh cm~(-3), and possesses a high electronic conductivity of 1 × 10~(-3) S m~(-1). These advantages of Se have stimulated growing research in developing Li-Se and Na-Se batteries over the past years. However, the practical application of these batteries has been hindered by the polyselenides dissolution (or shuttle effect phenomena), which could cause low Coulombic efficiency and poor cycling lifetime. Microporous carbon (MPC) has been fabricated through a facile carbonization method from polyvinylidene fluoride (PVDF) and used without any further activation as selenium host to produce MPC/Se composite employed as cathode in rechargeable lithium/sodium-selenium (Li/Na-Se) batteries and the electrochemical properties of the prepared cell have been investigated in Li-Se batteries. (figures 1 and 4).
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