Li-rich layered oxides (Li_1+zMn_xNi_yCo_1-x-yO₂) are considered as a most promising family of intercalation cathode materials for rechargeable lithium batteries, due to the advantages of high discharge capacity and high specific energy. Coupled with other benefits like high safety, low toxicity and costs, Li-rich materials are currently significantly attractive for high-power applications. However, weaknesses like intrinsic poor rate capability, dramatically decrease in the discharge potential plateau, irreversible volume expansion and capacity fade during long-term cycling are bringing up concerns about their practical utilization, which need to be surmounted.

Morphology tailoring is considered to be an efficient way to address these issues. It has been proved that the particle size, crystallinity and structural morphology have obvious effects on electrochemical performance of electrode materials. In order to improve the electrochemical performance of Li-rich, the special morphology of the material, with extra space between particles to buffer the volume change and the modified surface to enhance the electronic conductivity, was synthesized in this work.

Specifically, high crystallinity Li_1.2Mn_0.56Ni_0.16Co_0.08O₂ Li-rich porous materials integrating with an in-situ formed surface containing carbonaceous compounds are obtained through a novel facile approach. The rationally designed procedure involves the formation of a specific morphology of a hydroxide precursor assisted by a self-made template and subsequent high temperature treatment. The porous morphology is investigated using field-emission scanning electron microscopy and its surface area quantitatively examined by gas sorption analysis couple with the Brunauer-Emmett–Teller method. The porous morphology can be viewed from SEM image (Figure 1a), and it owns large surface area which is five time more than the sample in the normal shape. The crystallinity is characterized by X-ray diffraction and high-resolution transmission electron microscopy. X-ray photoelectron spectroscopy, CHN element analysis confirm the presence of the carbonaceous compounds in the surface composition. The prepared material exhibits superior discharge rate capability and excellent cycling stability. It shows minor capacity loss after 100 cycles at 0.5 C and maintains 94.9% of its initial capacity after 500 cycles at 2 C. Even more notably (Figure 1b), the “voltage decay” during cycling is also significantly decreased. It has been found that carbonaceous compounds play a critical role for reducing the layered to spinel structural transformation during cycling. Therefore, the present porous Li-rich material with surface modified a carbonaceous compounds represents an attractive material for advanced Lithium-ion batteries.