Primary Batteries – Non Chargeable/ Mechanically Rechargeable
Metal Air Battery (MAB) or Al-Air Battery (AAB)
Another category of aqueous battery systems is the MAB, which is an electrochemical cell with high specific energy, utilizing ambient air as the positive active material, and light metals (Li, Ca, Mg, Al, Zn or Fe), most commonly Al or Zn, as the negative active material, typically with an aqueous or aprotic electrolyte. The first Metal-Air battery was designed by Maiche in 1878 (Zn-Air) yet its commercial products started to appear in the market only in 1932. Following this development, other aqueous Fe-Air, Al-Air, and Mg-Air batteries were developed in the 1960s. It took another two decades for the first non-aqueous metal-air batteries to emerge (initially for Li-air and more recently Na-Air, K-Air & Al-Air). The specific capacity and energy density of MAB/ AAB cells are higher than that of LIB, making them a prime candidate for use in EVs. It has the potential of providing up to eight times the range of a LIB with a significantly lower total weight. Also aluminum is the most abundant metallic element (8.23% by mass in Earths’ crust and the third most abundant of all elements after oxygen and silicon). Since India ranks 5th in the world Aluminium reserves, the AlBs seem to be the most suitable for the Indian EV market.
Many efforts are underway to develop a ‘‘mechanically’’ rechargeable AIB where the discharged Alelectrode is physically removed and replaced with a fresh one, however, the recycling of removed discharged Al-electrode has to be done in dedicated plants where Aluminium is recovered from it, which is an energy-intensive process.
Work on EV powered by Al-Air battery has also been going on since 1989 when road tests of a hybrid Al-Air/LAB EV were reported while another Al-Air/plug-in hybrid minivan was demonstrated in Ontario in 1990. Phinergy9 in March 2013 released a video demonstration of an EV using an Al-Air battery being driven for 330 km while on May 27, 2013, the Israeli channel claimed that a car with a Phinergy battery in the back, traveled for 2,000 km before replacement of the Al anodes.
In India, while Log9 is a Bangalore-based company that has roots in the IIT Roorkee incubation center, is indigenously working on Al-Air batteries since 2015, Indian Oil Corporation (IOC) and Phinergy have recently formed a JV (in 2021) to build these ultra-lightweight Al-Air batteries for Electric Vehicles (EVs).
Advantages
- High Energy Density
- Higher Voltage
- Safer & Better
- By-Product Of Battery, Al (OH)3 Can Be Harvested & Recycled
- Aluminium Is Hydrophilic (Water-Attracting) Thus Battery Reaction Remains Stable
- Al-Air Batteries Are Cheaper Than LIB
- Environmentally Friendly
- Abundance Of Al In India-Reduced Dependency On Any Import For EV Battery
Disadvantages
- Sluggish Discharge Kinetics
- They Cannot Be Recharged Like LIB
- Recycling Of Its By Product Al (OH)3 Is Highly Energy Intensive
- Possibility Of Corrosion Of Al Metal With O2 & CO2 When Not In Use
- Availability Of Battery Swapping Stations & Al Charging Sharing Would Be Required
Fuel Cell (FC)
The concept of the FC was first demonstrated by Humphrey Davy in 1801, but the invention of the first working FC is credited to William Grove, a chemist, lawyer, and physicist who in 1842 called it a “gas voltaic battery”. More work followed between 1939 and 1949 to create various Alkaline FCs. FCs are similar to batteries except that the active materials are not the integral part of the cell (as in a battery), but they are fed into the cell from storage whenever power needs to be generated by FCs, and Oxygen or air is the predominant oxidant and is fed into the cathode side of the FC.
However, the FCs differ from the battery in one way i.e. it can produce electrical energy as long as the active materials are fed to the electrodes or the electrodes do not fail. The electrode materials of the FCs are inert in that they are not consumed during the cell reaction, but have catalytic properties which enhance the electro reduction or electro-oxidation of the reactants (the active materials). The anode active materials used in FCs are generally gaseous or liquid and are fed into the anode side of the FC. As these anode materials are more like the conventional fuels used in heat engines, the term ‘‘Fuel Cells’’ has become popular to describe these devices.
A Fuel Cell Electric Vehicle (FCEV) is an EV that uses a FC, sometimes in combination with a small battery to power its on-board electric motor. FCs of these FCEVs generate electricity generally using oxygen from the air and compressed hydrogen stored in taken mounted on a vehicle. Most FCEVs are classified as zero-emissions vehicles that emit only water and heat.
FCs have been used in various kinds of vehicles including forklifts, especially in indoor applications where their clean emissions are important to air quality, and in space applications. However, the first commercially produced hydrogen FC automobile, the Hyundai Tucson FCEV, was introduced in 2013, Toyota Mirai followed in 2015 and then Honda entered the market. The new generation of FCs are being developed and tested in trucks, buses, boats, motorcycles, and bicycles, among other kinds of vehicles.
Advantages
- High Efficiency
- Power Quality Does Not Degrade Over Time.
- More Silent And Smooth
- Environmental Friendly As No Harmful Emissions Are There
- FCs Are Lighter And Compact
Disadvantages
- Expensive To Manufacture Due To The High Cost Of Catalysts (Platinum)
- Considering The Explosive Nature Of Hydrogen, Creating Supply Chain Would Be A Challenge
- Current FC Technologies Still Have Saleability Challenge
- Highly Explosive Gas And Its Handling Would Always Be A Safety Concern
- Hydrogen Is Expensive To Produce And Not Widely Available
Some Other Battery Technologies Currently Evolving
Graphene Aluminium Battery: Graphene-based batteries have exciting potential but they are not fully commercially available yet. Many companies are already working on it with the combination as Metal-Air Battery or to improve LIB performance (Log 9 Materials, Samsung & Huawei) while in June 2014, US-based Vorbeck Materials announced the Vor-Power battery providing 7,200 mAh and is probably the world’s first graphene-enhanced battery.
Cobalt-Free Lithium-Ion Battery: Researchers at the University of Texas have developed a LIB that doesn’t use cobalt for its cathode.
Silicon Anode Lithium-Ion Batteries In 2015, Tesla founder Elon Musk claimed that silicon in Model S batteries increased the car’s range by 6%.
Lithium-sulfur Batteries: The invention dates back to the 1960s, when Herbert and Ulam patented in 1962, a primary battery employing lithium or lithium alloys as anodic material, sulfur as cathodic material, and an electrolyte composed of aliphatic saturated amines.
Sand Battery: This alternative type of lithium-ion battery uses silicon to achieve three times better performance than current graphite Li-ion batteries.
Vertically Aligned Carbon Nanotube Electrode: NAWA Technologies has designed and patented an Ultra-Fast Carbon Electrode, which can be a game-changer in the battery market. It uses a Vertically-Aligned Carbon Nanotube (VACNT) design which can boost battery power (10X), energy storage (3X), and the lifecycle of a battery (5X). The technology could be in production by 2023.
Gold Nanowire Batteries: Researchers at the University of California Irvine have cracked nanowire batteries that can withstand plenty of recharging.
Battery As EV’s Structural Component: Research at the Chalmers University of Technology are working on new batteries not as a power source, but also as a structural component & once developed would be making batteries strong enough to get integrated into vehicle’s structure to become an integral part of vehicles serving a dual purpose, weight reduction, and power supply.
Batteries Free From Heavy Metals like nickel and cobalt (IBM is developing a product and that can potentially out-perform lithium-ion)
Foam Batteries: Prieto11 is a company that has managed to make 3-D batteries, using copper foam substrate. This means these batteries will not only be safer, but they will also offer longer life, faster charging, five times higher density, be cheaper to make, and be smaller than current offerings. New Foam Batteries Promise Fast Charging, Higher Capacity in an almost limitless variety of shapes, they could offer energy storage applications previously unimaginable.
Ryden Dual Carbon Battery: Power Japan Plus has already announced this new battery technology called Ryden dual carbon. Not only will it last longer and charge faster than lithium but it can be made using the same factories where lithium batteries are built.
Sodium-Ion Batteries: Scientists in Japan are working on new types of batteries that don’t need lithium like your smartphone battery. These new batteries will use sodium, one of the most common materials on the planet rather than rare lithium – and they’ll be up to seven times more efficient than conventional batteries.
Epilogue
With so many players in the battery market eying for future EVs, it would be interesting to watch as to in whose favour this “War of The Battery” tilts finally to capture the Global Market as well as the Indian EV market. Though in current times we do not have legends like Edison & Westinghouse/ Nikola Tesla, still in present times we do have Elon Musk, China, and the rest of the world to fight this “War of The Battery”. This may take many years before the dust settles down and one/few winners emerge, which may not be with the best of technology but a technology with is environment friendly, has mass acceptance, ease of operation, longevity range, reliable and is low cost, reliable & safe. We need to wait and watch for the ends result of this WAR keeping in mind following
key learnings from all the previous technology/ standards wars:
- First-Mover Advantage Is No Guarantee Of Success
- Multiple Technologies Can Coexist And Supplement Each Other
- These Standards Wars Are Often More Than The Superiority Of Technology
- Framing The Challenges & Issues Are Critical For Success.
…concluded
Prabhat Khare possesses a BE (Electrical) degree from IIT Roorkee (Gold Medalist). Now, he is the Director of KK Consultants. He is also a BEE Certified Energy Manager and a Lead Assessor for ISO 9K, 14K, 45K & 50K.
