Batteries can be classified according to their chemistry or specific electrochemical composition, which heavily dictates the reactions that will occur within the cells to convert chemical to electrical energy. Battery chemistry tells the electrode and electrolyte materials to be used for the battery construction.
Each battery is designed to fulfill a specified purpose and can be used according to the requirement. There are mainly two categories of battery called primary and secondary cells. However, batteries are classified into four broad categories namely primary cell, secondary cell, fuel cell and reserve cell.
Primary batteries are “dry cells”. They are called as such because they contain little to no liquid electrolyte. Again, these batteries cannot be recharged, thus they are often referred to as “one-cycle” batteries.
Power batteries can be classified into various categories based on the cathode material used, such as NCM, LFP, LMO, and LTO batteries. Among these, NCM and LFP batteries are considered to be the prevalent options in the current market. The statistics of NCM and LFP power battery production in China from 2017 to 2021 are shown in Fig. 4 b.
Secondary battery chemistries, distinct from primary batteries, are rechargeable systems where the electrochemical reactions are reversible. Unlike primary batteries that are typically single-use, secondary batteries, such as lithium-ion and nickel-metal hydride, allow for repeated charging and discharging cycles.
Primary batteries come in three major chemistries: (1) zinc–carbon and (2) alkaline zinc–manganese, and (3) lithium (or lithium-metal) battery. Zinc–carbon batteries is among the earliest commercially available primary cells. It is composed of a solid, high-purity zinc anode (99.99%).