Breaking Down Battery Technology
Today, while we are in the midst a major healthcare crisis, there is a well anticipated — greater concern towards climate change. And evidently, we are witnessing an accelerated shift of focus towards renewable energy generation. However, storing energy is just as important as generating it. Storage enables the integration of renewable energy on a large scale, bringing together energy innovation and technology to address challenges especially in developing countries.
At the core of energy storage are batteries, simple devices that convert stored chemical energy directly into electrical energy. A battery is a pack of one or more cells, each of which largely has three major components:
· (-) Anode (negative electrode that gets oxidised),
· (+) Cathode (positive electrode that is reduced) and
· Electrolyte (medium that provides the ion transport mechanism between the cathode and anode of a cell)
Creating a simple battery is quite easy, I believe that the major challenge lies in replacing the ‘one-size fits all’ approach with a uniquely optimised approach (balancing power density and energy density) for customised applications at an affordable cost.
Energy density is the amount of energy in a given mass (or volume) and power density is the amount of power in a given mass; In simple terms- power density tells how fast your car can drive and energy density tells how far your car can drive.
Majority of the world is using Lithium-Ion batteries (Invented in the 1970s) for multiple applications but with the advancements in chemistry and material science, the new age start-ups have begun commercialising smart innovations of battery technologies. Below, I have categorised various use cases and attempted to highlight the most-relevant battery technologies for them.
1) Mobility for short to medium distance with modest energy and power requirements:
The most common type of battery commercially produced and utilised is lithium-ion. These batteries use lithium metal as anode and a metal oxide for cathode. Li-ion batteries are a great choice for electrifying cars and 2 wheelers because of their high efficiency, energy density, temperature performance, self-discharge rates and lower costs.
Although widely adopted in the vehicle market, lithium-ion batteries require further development to sustain their dominating roles amongst other battery technologies. Highlighting few areas where companies can innovate to optimise the existing Li-ion batteries:
a) Healing mechanisms to improve battery life
Electrochemical processes in the battery lead to degradation mechanisms that reduce battery performance over time. Start-ups are building smart solutions like preventive material technology which can help in preventing the clogging and degradation of electrodes hence improving the overall life cycle of the battery.
b) Improving energy density of the battery using material science
Existing Li-ion batteries hold a potential to improve the overall energy density of the systems. Material science companies have started exploring ultra-high-performance materials for electrodes in Li-ion batteries — which will multiply the energy density of existing batteries.
Going forward, battery manufacturers seemingly have to pull more and more levers to improve the existing battery performance while developing highly efficient manufacturing lines to decrease production costs and increase adoption.
2) Mobility for medium to long distances with large energy requirements:
It is now believed that further improvements on Li-ion battery can bring in at-most additional 30% increase in energy density. Such an upper limit means that it would be difficult to achieve long driving ranges (e.g. 500 km) with these batteries. Another drawback of a Lithium-ion battery is the time needed for recharging it which is a big inconvenience when carrying multiple passengers on longer routes.
A much safer and easier option that surfaced in the recent years are Hydrogen Fuel Cells. These devices can generate electricity, water and heat from hydrogen and oxygen. Not only do they offer greater ranges, are lighter and occupy smaller volumes but they can be recharged in a matter of minutes like gasoline vehicles.
Hydrogen fuel cells and Lithium-ion batteries can and should co-exist, with each fulfilling its niche. Li-ion batteries are ideal for commuter cars and for use in many commercial applications with repeatable routes, while fuel cells are suitable for drivers that frequently need to drive larger vehicles like long-haul trucks, buses, and ships over longer routes. Constant ongoing R&D on hydrogen fuel cells should help in getting its costs down while improving the efficiency, post which it holds solid potential for mass commercialisation.
3) Mobility for long distances with extremely large energy and power requirements (Against gravity):
For a large passenger aircraft to take off, cruise, and land hundreds of kilometres away would require conventional batteries that weigh thousands of kilograms — far too heavy for the plane to be able to get into the air in the first place. To make electric planes a reality the world needs a battery solution which has super high energy and power density.
Metal-air batteries are supposed to be a revolution in battery technology that can make electric planes a reality. A metal-air battery uses some type of metal for the anode, air as the cathode, along with a liquid electrolyte. These batteries are helpful in providing longer ranges with high power density at lower weight profiles which makes them a perfect fit for aerial use cases. Also, the use of a lithium-ion battery is possible in a temperature range of 10°C to +55°C whereas metal air batteries can comfortably work between −40 to +70 °C which makes them the best fit for aerial applications.
Such batteries are still far from commercialisation, but we can expect early adoption and initiation in the next 5 years.
4) Non-mobility applications with low power and energy requirements:
Lithium may not be the best fit for applications that have smaller power needs and high price-sensitivity. Generally, these batteries are an overkill for non-mobility use cases like laptops and mobile phones. And so, companies are now looking at replacing the lithium ions that shuttle between the two electrodes with ions and electrolytes that may be cheaper and potentially safer, like those based on sodium, magnesium, zinc or sulphur.
Batteries are often under-appreciated when they work as designed, but harshly criticised when they do not live up to expectations. The recommendations made above are ambitious and would hold true in an idealistic scenario, but we are positive that new age companies in the battery technology ecosystem can make this a reality very soon.
About the author: I am currently a part of the investment team at Speciale Invest. Have previously worked with Flipkart and hold an engineering degree from BITS Pilani. Can be reached out on https://www.linkedin.com/in/anirudh-garg98/ or @Anirudh79452232
About Speciale Invest: Speciale Invest is a deep science and technology venture firm investing across enterprise software (AR/VR, Cloud, Voice AI, Vision AI, Computer Vision) and industrial hardware (propulsion tech, robotics, rocket engines, lithium tech, micro-electronics, photonics). We are typically first institutional investors and have been early pioneers of AI SaaS, Electric Mobility, Space Tech, Vision based Robotics and Photonics.