In literature, very high specific energies can be achieved (Figure ); however, many fall short of specific power values obtained in industry (Figure ). Interestingly, when considering all secondary literature batteries (i.e. non-primary batteries), there is not a significant trade-off between specific energy and specific power; rather, a generally increasing trend is observed. This could be related to the amount of excess materials in the battery and the battery's ability to function well with an optimized amount of excess material or to a trade-off not seen in metrics other than cell-level specific energy and specific power.