Li-ion batteries: news, progress, history and background

Hydrocarbon polymer electrolyte membrane (Photo credit: SandiaLabs ) The highly heat-resistant separator coated with Teijinconex meta-aramid The new separator, which is coated with a fluorine-based compound, is designed for use in laminated-type LIBs. Such LIBs, which feature a gel polymer electrolyte, are used in tablets and smartphones. The new separator readily adheres to the polymer electrolyte and is highly resistant to oxidation, resulting in LIBs that offer greater safety, higher output and longer lifespans. The highly heat-resistant separator coated with Teijinconex meta-aramid maintains its shape even at 250℃. In spot heating tests, Teijin has verified that the separator does not break down even at 350℃. Also, thanks to the separator's superior resistance to oxidation, it enables unprecedented capacity and energy density for liquid-electrolyte cylindrical LIBs used in products including PCs and vehicles. These LIBs also achieve higher levels of safety and longer life

GBL-based electrolyte for Li-ion battery: thermal and electrochemical performance   Journal of Solid State Electrochemistry: Volume 16, Issue 2 (2012), Page 603-615 Thermal stability, flammability, and electrochemical performances of the cyclic carbonate-based electrolytes [where γ-butyrolactone (GBL) is a main component (at least 50 vol.%) among of EC and PC with LiBF 4 ] have been examined in comparison with contemporary (EC/EMC, 1:3 vol.%, 1 M LiPF 6 ) electrolyte by DSC, accelerating rate calorimetry (ARC), AC impedance, and cyclic voltammetry (CV). This study shows that GBL-based electrolytes have perfect thermal stability and will improve Li-ion battery safety (including flammability) without performance trade-off with the accurate combination of active materials and separator. Several types of negative electrode materials (such as hard carbon, MCMB, and SWF) have been tested to evaluate GBL-based electrolyte influence on SEI formation and battery performance. Finally, GBL-bas