By Dr N S Suresh – Research Scientist and Bhupesh Verma – Senior Research Analyst, Center for Study of Science, Technology and Policy (CSTEP)
The performance of an electric vehicle (EV) is largely dependent on a battery and its materials composition. Battery selection is based on performance characteristics, such as energy and power density, life cycle, safety, charging/discharging rate, cost, etc. Currently, the market is dominated by Lithium-ion batteries (LiBs). The most prominent material compositions in LiBs are Lithium Nickel Manganese Cobalt (LNMC), Lithium Nickel Manganese Oxide (LNMO), and Lithium Iron Phosphate (LFP) as cathode materials and graphite as anode material. Lithium and cobalt have lesser energy density. Also, these materials are scarce. Therefore, new material compositions are being tried to enhance the performance, environmental friendliness, and sustainability of batteries. The following Table provides the summary of performance indicators for various existing and emerging battery technologies.
| Material composition(Cathode/Anode) | Energy density* (Wh/kg) | Cycle life* | Cost* (INR/kWh) | Safety | Remarks |
| Existing | |||||
| LNMC/graphite | 140–200 | 1,000–2,000 | 13,000–15,000 | Less safe because of cobalt | Most proven but challenge with materials |
| LFP/graphite | 90–140 | 2,000 | 17,000–24,000 | Safe at high temperature (60–80°C) | Cheaper and F&P abundant |
| LMO/graphite | 100–140 | 1,000–1,500 | 7,500–14000 | Safe and stable at high temperature | Manganese abundant |
| Emerging | |||||
| LiS/graphite | 450–600 | 1,500 | 15,000 | Significantly safe | Lightweight, cheaper and abundant materials |
| LNMC/Silicon | 205 | 5,000 | 12,000 | Swelling issues | Silicon has 10 times higher energy density |
| Solid-state LiB | 500 | 10,000 | 60,000 | Significantly safe | Fast charging, amicable even in cold regions |
| Zinc-air | 200–600 | 5,000 | 19,000 | Significantly safe | Abundant |
| Al-air | 8,100 | 3,000 km/100 kg | 2,500 | Significantly safe | Cheaper and abundant materials |
| Graphene-Al | 80–225 | 250,000 | 7,500 | Significantly safe | Fast charging; mass production is a challenge |
*approximately
As seen in the Table, emerging technologies have higher energy density (2–4 times) compared to traditional batteries. This leads to an increase in the life of the battery and run time, and minimises footprint size. Emerging batteries (except LiS) offer greater life cycle and can even be used for long-distance travel (over 300 km) per charge. Further, these batteries have enhanced safety characteristics and raw materials are widely available (including in India). Some emerging batteries have special features. Metal-air batteries do not require electricity for charging and require the replacement of metals (Aluminium/Zinc) for every cycle. Similarly, graphene-based batteries can be charged quickly (15 sec) and facilitate more cycles (but have low energy density). As for costs, emerging batteries are more feasible except for solid-state batteries (due to high equipment cost). Materials used in most emerging batteries are environmentally friendly, including when it comes to the afterlife. This indicates that emerging battery chemistries can play a crucial role in EVs alongside most proven traditional batteries.
India is targeting 30% of EV deployment by 2030. To meet this target, the Government of India announced plans for indigenous manufacturing with an earmarked production-linked incentive scheme of INR 18,000 Crore. The current composition of LiBs (Li, Co) would pose implications relating to materials availability, economics, and environment. Therefore, it is imperative to utilise domestically available materials such as Aluminium, Sulphur, Iron, Phosphorus, etc. The economies of scale through indigenous plants would pave a path for further cost reduction and sustainable battery manufacturing.
