Ultrathin 3 V Spinel Clothed Layered Lithium-Rich Oxides as Heterostructured Cathode for High-Energy and High-Power Li-ion Batteries^†

In an attempt to overcome the drawbacks of high-capacity layered lithium-rich cathodes xLi₂MnO₃·(1–x) LiMO₂ (0 < x < 1, M = Mn, Ni, and Co), the spinel clothed layered heterostructured materials, x’Li₄Mn₅O₁₂·(1–x’) Li[Li_0.2Mn_0.55Ni_0.15Co_0.1]O₂ (x’ = 0.01, 0.03, 0.05) have been proposed and synthesized as high-performance cathode materials for high-energy and high-power Li-ion batteries. Based on the characterizations of X-ray diffraction (XRD), transmission electron microscopy (TEM), Raman scattering spectroscopy, it is indicated that ultrathin 3 V spinel Li₄Mn₅O₁₂ has been successfully clothed on the layered lithium-rich cathode. Electrochemical tests demonstrate the sample 0.01Li₄Mn₅O₁₂·0.99 Li[Li_0.2Mn_0.55Ni_0.15Co_0.1]O₂ with an ultrathin clothing layer of spinel phase, exhibits the highest reversible capacity of 289.4 mAh g^–1 and maintains 259.8 mAh g^–1 after 80 cycles at 0.1 C rate. Meanwhile, it delivers outstanding rate discharge capacities of 229.4 mAh g^–1 at 1 C, 216.8 mAh g^–1 at 2 C and 184.4 mAh g^–1 at 5 C as well as alleviated voltage fade. It is believed the ultrathin clothing spinel layer plays a vital role in the modification of the materials kinetics, and structural and electrochemical stability of the heterostructured cathode.