• Lithium-Ion Battery

Lithium-Ion(Li-Ion) Batteries are the most commonly used battery in electric vehicles. It is estimated that Li-Ion batteries will take up to a 90% share of the EV battery market by 2025. The cathode of the Li-Ion battery is made of lithium cobalt oxide and the anode contains graphite. The Li-Ion batteries are lightweight, have a good charge cycle rate (they are capable of being recharged many times), higher energy density (100-265 Wh/kg or 250-670 Wh/L), higher cell voltage, and a better self-discharge rate (at only 5 percent per month). Li-ion batteries have no memory effect, a detrimental process where repeated partial discharge/charge cycles can cause a battery to ‘remember’ a lower capacity. An amazing specific energy rate of 140+ Wh/kg is the Li-Ion battery’s main advantage. High energy density allows for a lighter battery weight, which increases an EV’s range and performance.

Many types of Li batteries are available, such as lithium nickel cobalt aluminum oxide (NCA), lithium-manganese oxide (LMO), lithium nickel manganese cobalt (NMC), lithium titanate (LTO) and lithium-iron-phosphate (LFP). The increasing popularity of EVs has brought battery technology into focus. Studies of new advanced battery types abound. Recent EV battery designers are focusing on providing features like fire resistance, environmental friendliness, fast charging, and long life span. At times, competing requirements have sacrificed specific energy and power properties.

  • Lead Acid Battery

Lead-acid Battery was the first rechargeable battery for commercial use.

It was invented by the French physician Gaston Planté in 1859. Despite its advanced age, the lead chemistry continues to be in wide use today. There are good reasons for its popularity; lead-acid is dependable and inexpensive on a cost-per-watt base.

Two common lead-acid battery types are the engine starter batteries and deep cycle batteries used in EVs (these days in forklifts or golf carts). This battery type requires inspection of the electrolyte level and has a short life span, of approximately three years. These batteries have a poor specific energy rate (34 Wh/kg). Because they are heavy (remember, it’s made from lead) in order to provide sufficient energy, in an EV application these batteries could represent 25 to 50 percent of the vehicle’s total mass. They also have a negative environmental impact, generate harmful gases, are toxic, and contain concentrated sulfuric acid. This type of battery was used in the early EVs (e.g., General Motors EV1). Taking into consideration all the mentioned disadvantages and the new developments available in other battery types, lead-acid batteries are not used in any new EV designs.