Commonly used cathode materials for power batteries mainly include modified lithium manganese oxide, lithium iron phosphate, ternary materials, and lithium-rich manganese-based cathode materials.
In comparison, these four materials each have their own strengths and weaknesses in terms of performance:
Regarding modified lithium manganese oxide, its average voltage relative to metallic lithium is 4.0V, with a usable specific capacity of 110Ah/kg and a specific energy of 440Wh/kg. When combined with a graphite anode, the expected specific energy of the battery is 140Wh/kg. This cathode material offers good safety and low cost, but its lifespan in high-temperature environments is relatively short.
Regarding lithium iron phosphate, its average voltage relative to lithium metal is 3.4V, with a usable specific capacity of 155Ah/kg and a specific energy of 527Wh/kg. When combined with a graphite anode, the expected specific energy of the battery is 160Wh/kg. This cathode material offers the best safety, lower cost, and a long lifespan.
Regarding ternary materials, their average voltage relative to lithium metal is 3.8V, with a usable specific capacity of 160Ah/kg and a specific energy of 646Wh/kg. When combined with a graphite anode, the expected specific energy of the battery is 240Wh/kg. This cathode material has low safety, high cost, and a long lifespan.
Regarding lithium-rich manganese-based cathodes, the average voltage relative to metallic lithium is 3.6V, with a usable specific capacity of 270 Ah/kg and a specific energy of 927 Wh/kg. Combined with a graphite anode, the expected specific energy of the resulting battery is 280 Wh/kg. This cathode material has a relatively low cost, but its lifespan remains an issue and requires further research.
