Low-temperature tolerant lithium-rich manganese-based cathode enabled by facile SnO2 decoration

Abstract

Lithium-rich manganese-based cathode materials have gained increasing research attention because of their superior specific capacity and high operating voltage. However, they suffer from voltage decay and unsatisfied stability during cycling. Meanwhile, the lithium-rich cathode materials could barely be stably operated at low temperatures, limiting their practical application. Herein, low-temperature tolerant Li[Li_0.144Ni_0.136Co_0.136Mn_0.544]O₂ cathode material is obtained via facile SnO₂ decoration. With the SnO₂ modification, LiF-enriched cathode-electrolyte interphase (CEI) is formed on the surface of Li[Li_0.144Ni_0.136Co_0.136Mn_0.544]O₂ at both ambient and low temperatures, thereby facilitating the Li⁺ diffusion on the surface. Furthermore, the modified Li[Li_0.144Ni_0.136Co_0.136Mn_0.544]O₂ demonstrates suppressed voltage decay, high structure stability, and low activation energy for Li⁺ diffusion in the CEI layer and charge transfer. Consequently, the SnO₂-decorated Li[Li_0.144Ni_0.136Co_0.136Mn_0.544]O₂ exhibits a high capacity of 221.0 mA h g⁻¹ over 200 cycles, with a high capacity retention of 97.1% at 100 mA g⁻¹ at room temperature. Remarkably, SnO₂-decorated Li[Li_0.144Ni_0.136Co_0.136Mn_0.544]O₂ can be successfully operated at low temperatures with a high discharge capacity and outstanding cycle stability. At 0 °C, a high discharge capacity of 111.5 mA h g⁻¹ with a capacity retention of 79.9% is achieved over 500 cycles at 100 mA g⁻¹. Even at −20 °C, a high capacity of 109.9 mA h g⁻¹ and a high capacity retention of 84.2% after 400 cycles are obtained at 25 mA g⁻¹. This work provides a facile method to enhance the performance of lithium-rich cathode materials and would promote the development of batteries based on lithium-rich cathodes for broader applications.