Abstract: A single step, in situ curing method for making gel polymer lithium ion rechargeable cells and batteries is described. This method used a precursor solution consisting of monomers with multiple functionalities such as multiple acryloyl functionalities, a free-radical generating activator, nonaqueous solvents such as ethylene carbonate and propylene carbonate, and a lithium salt such as LiPF6. The electrodes are prepared by slurry-coating a carbonaceous material such as graphite onto an anode current collector and a lithium transition metal oxide such as LiCoO2 onto a cathode current collector, respectively. The electrodes, together with a highly porous separator, are then soaked with the polymer electrolyte precursor solution and sealed in a cell package under vacuum. The whole cell package is heated to in situ cure the polymer electrolyte precursor.

Abstract: The present invention relates to a new sandwich cathode design having two cathode active materials provided on opposite sides of a current collector. The respective active materials are similar in terms of, for example, their rate capability, their energy density, or some other parameter. However, one material may have an advantage over the other in one characteristic, but is disadvantageous in another. The cathode is built in a sandwich configuration having a first one of the active materials sandwiched between two current collectors. Then, the second active material is provided in contact with at least the other side of one of the current collectors, and preferably facing the anode. An exemplary cathode has the following configuration: MnO2/current collector/SVO/current collector/MnO2.