Rapid and Low‐Carbon Emission Synthesis of Stable LiNi0.5Mn1.5O4 Cathode for Li‐Ion Batteries

Abstract

The surging adoption of lithium‐ion batteries, driven by diverse applications including electric vehicles, renewable energy storage, and portable electronics, has intensified the demand for high‐energy cathode materials. The existing methods to produce cathode materials typically include high‐temperature (>800 °C) sintering for a long period of time (>15 h), which are not only energy‐intensive but also significantly contribute to CO2 emissions. This investigation presents the ultrafast microwave solid‐state process to produce battery cathode materials by synthesizing high‐voltage LiNi0.5Mn1.5O4 (LNMO). Benefiting from rapid direct heating with an ultrahigh heating rate (>50 °C), high‐purity and well‐defined LNMO crystals are produced in a much shorter time (2 h) as compared to the conventional heating methods (>15 h). It is revealed that microwave irradiations substantially accelerate the reaction kinetics and enhance the homogeneity of LNMO. The as‐synthesized LNMO cathode delivers an excellent discharge capacity of 137.96 mAh g−1 (at 0.05 C), and outstanding cycling stability (≈63% retention over 280 cycles). The in situ characterizations elucidate the charge kinetics, suggesting high structural stability of the LNMO cathode during the reversible intercalation of Li‐ions. These encouraging results pave the way toward the manufacturing of other oxide materials for energy storage and other applications using the rapid microwave method.