Zero-strain Mn-rich layered cathode for sustainable and high-energy next-generation batteries

Abstract

The increasing demand for high-energy Li-ion batteries for the electrification of personal transportation may lead to uncertainty in the global supply of raw materials (Co and Ni). Here we propose a novel Mn-rich composition, which has a quasi-ordered structure with previously unobserved two intermixed cation-ordering sequences. The partially ordered structure stabilizes the delithiated cathode at a high cut-off voltage, offering strain-free characteristics, with structural variations along both the a and c axes limited to approximately 1%. Consequently, the cathode can operate at 4.6 V while delivering a reversible capacity comparable to that of Ni-rich Li(Ni0.8Co0.1Mn0.1)O2. Moreover, a high capacity is maintained during long-term and high-voltage cycling in full cells with exceptional thermal safety. The high-performance Mn-rich layered cathodes characterized by quasi-ordered crystal structure can potentially relieve supply uncertainty resulting from the rising demand for Ni in the battery industry and environmental concerns associated with the extraction of Ni from its ores.