The core materials of lithium cobalt oxide batteries are cobalt and lithium. The cycle performance of lithium cobalt oxide batteries is closely related to these two materials. Below, we will take an in-depth look at the advantages and disadvantages of their electrochemical performance based on the working principle of lithium cobalt oxide batteries. Lithium cobalt oxide, with the chemical formula $\boldsymbol{LiCoO_2}$, is an inorganic compound commonly used as the cathode material for lithium-ion batteries. ### 1. Advantages of Lithium Cobalt Oxide Batteries 1.  **Superior electrochemical performance**: The average capacity fade per cycle is less than 0.05%; the initial discharge specific capacity exceeds 135 mAh/g; the ratio of the initial discharge plateau at 3.6 V is over 85%. 2.  **Excellent processability**. 3.  **High tap density**, which helps improve the volumetric specific capacity of the battery. 4.  **Stable product performance and good consistency**. 5.  **High operating voltage, steady discharge, high specific energy and good cycle performance**. 6.  **Suitable for high-current discharge and lithium-ion intercalation/deintercalation**, making it the first material to be adopted in lithium-ion batteries. ### 2. Disadvantages of Lithium Cobalt Oxide Batteries 1.  The actual specific capacity of $\boldsymbol{LiCoO_2}$ is approximately 140 mAh/g, which is only about 50% of its theoretical capacity (274 mAh/g). 2.  During repeated charge-discharge cycles, the repeated intercalation and deintercalation of lithium ions cause the structure of the active material to change after multiple contractions and expansions, leading to increased internal resistance and capacity loss of $\boldsymbol{LiCoO_2}$. ### Reactions During the Charge-Discharge Process of Lithium Cobalt Oxide Batteries **Charging reactions** - Cathode: $\boldsymbol{LiCoO_2 = Li_{1-x}CoO_2+xLi^++xe^-}$ - Anode: $\boldsymbol{6C+xLi^++xe^- = Li_xC_6}$ **Discharging reactions** - Cathode: $\boldsymbol{Li_{1-x}CoO_2+xLi^++xe^- = LiCoO_2}$ - Anode: $\boldsymbol{Li_xC_6 = 6C+xLi^++xe^-}$ Lithium cobalt oxide batteries feature stable structure, high specific capacity and outstanding comprehensive performance, but they suffer from poor safety and very high cost. They are mainly used in small and medium-sized battery cells, and widely applied in small electronic devices such as laptops, mobile phones and MP3/MP4 players, with a nominal voltage of 3.7 V.