Revitalizing High-Performance Lithium Primary Batteries via the Synergetic Effect of CrOx and CFx
Chromium oxides (CrOx) and fluorinated graphite (CFx) are two typical cathode materials for lithium primary batteries. The former possesses the highest theoretical energy density but suffers from low practical capacity and inferior rate capability; the latter has the highest theoretical discharge capacity but fails to support fast discharge. Combining the merits of both cathodes via a composite design is desirable, yet the electrochemical performance of such composites remains unsatisfactory. In this work, we identified that by regulating the overlapped discharge potential of these two cathodes, fluorine atoms migrate from CFx to CrOx, leading to a homogeneous distribution of LiF and improved ionic and electronic conductivity, ultimately enhancing high-rate discharge performance. Benefiting from this synergetic effect, the CrOx/10%eCFx composite exhibits a considerably high energy density of 496.59 Wh kg−1 at a power density of 49.7 kW kg−1 (50 C), far superior to pure CrOx and CFx electrodes. We believe that the high-performance CrOx/eCFx composite cathode will justify its practical application in revitalizing advanced lithium primary batteries.