The prospectus of fundamental engineering materials for high-energy batteries are being explored to improve key features such as specific capacity, thermal characteristics, and cycle life. Biological waste in the form of an avian eggshell are unusual kind of biomaterial, as its formation is rapid indicating the generation of an enormous bio-waste. Avian eggshell possesses high amount of calcium carbonate, which are thermochemically reduced to calcium oxide and then in-situ coated over nickel-rich LiNi0.8Co0.1Mn0.1O2 (NCM811). The effect of coating CaO over NCM811(CaO-NCM811) particles are systematically investigated as a functional material for Li-ion batteries through techniques, such as galvanostaic charge-discharge cycling and electrochemical impedance spectroscopy. Electrochemical results suggest that the optimum amount of CaO (1 wt%) plays a vital role in achieving an improved performance of NCM811 by reducing its surface chemistries. The present study signifies the use of biological waste avian eggshell as additives or coating agents for electrode materials and paves the way significantly to reduce the amount of biological wastes generated.