The voltage decay of lithium-rich layered oxides (LLOs) is still one of the key challenges for their applica-tion in commercial battery although these materials possess the advantages of high specific capacity and low cost.In this work,the relationship between voltage decay and tap density of LLOs has been focused.The voltage decay can be significantly suppressed with the increasing tap density as well as the homog-enization of the primary or secondary particle size of agglomerated spherical LLOs.Experimental results have shown that an extreme small voltage decay of 0,98 mV cycle-1 can be obtained through adjusting the tap density of agglomerated spherical LLOs to 1.99 g cm-3,in which the size of primary and secondary particles are uniform.Our work offers a new insight towards the voltage decay and capacity fading of LLOs through precursor preparation process,promoting their application in the real battery in the future.