Sandwich cathode design using mixtures of two active materials for alkali metal or ion electrochemical cells

摘要

A new sandwich cathode design is provided having a first cathode structure of a first cathode active material of a relatively low energy density but of a relatively high rate capability, for example SVO, mixed with a second cathode active material having a relatively high energy density but a relatively low rate capability, for example CF_x, with the percentage of SVO being less than that of CF_x and sandwiched between two current collectors. Then, a second cathode mixture of SVO and CF_x active materials is contacted to the outside of the current collectors. However, the percentage of SVO to CF_x is greater in the second structure than in the first. Such an exemplary cathode design might look like:    (100-y)% SVO + y% CF_x, wherein 0 ≤ y ≤ 100/current collector/(100-x)% SVO + x% CF_x, wherein 0 ≤ x ≤ 100/current collector/(100-y)% SVO + y% CF_x, wherein 0 ≤ y ≤ 100, and wherein the ratio of x to y is selected from the group consisting of y x, x y and x = y.