A novel intrinsically porous separator for self-standing lithium-ion batteries

gamma-LiAlO2, Al2O3 and MgO were used as fillers in a PVdF-HFP polymer matrix to form self-standing, intrinsically porous separators for lithium-ion batteries. These separators can be hot-laminated onto the electrodes without losing their ability to adsorb liquid electrolyte. The electrochemical stability of the separators was tested by constructing half-cells with the configuration: Li/ fibre-glass/filler-based separator/electrode. MgO-based separators were found to work well with both positive and negative electrodes. An ionic conductivity of about 4 x 10(-4) S cm(-1) was calculated for the MgO-based separator containing 40% 1 M solution of LiPF6 in an EC/DMC 1: 1 solvent. Self-standing, lithium-ion cells were constructed using the MgO-based separator and the resulting battery performance evaluated in terms of cyclability, power and energy density. (C) 2002 Elsevier Science Ltd. All rights reserved.