Li-Fe Phosphate Batteries: Rising Star in Energy Storage
Lithium-ion batteries are the premier choice for rechargeable power sources, such as cell phones, vehicles, and numerous electronic devices owing to their high energy densities and extended lifespans. Among the Li-ion battery family, Lithium-iron phosphate (LFP) batteries emerge as a revolutionary option due to their exceptional thermal stability, safety, and cost-effectiveness. Major automakers have either integrated or are exploring the integration of LFP-based batteries into their newest electric vehicle (EV) models. The Economic Survey 2023 predicts that the Indian electric vehicle market will grow at a compound annual growth rate (CAGR) of 49 % between 2022 and 2030, achieving 10 million sales annually by 2030. Considering this unprecedented growth leading domestic Li-ion battery manufacturers have partnered with international firms to produce LFP batteries locally, catering to the surging demand.
Typically, Li-ion batteries employ either a non-flammable organic solvent or a polymer gel as the electrolyte that allows for the movement of lithium ions without posing significant safety risks. Lithium ions are stored in the graphite anodes via a process called intercalation, where the ions are inserted between the two-dimensional graphene layers that constitute bulk graphite. A range of materials, such as lithium cobalt oxide (LiCoO2, LCO), lithium manganese oxide (LiMn2O4, LMO), lithium nickel manganese cobalt oxide (NCM or NMC), lithium nickel cobalt aluminium oxide (NCA), and lithium iron phosphate (LiFePO4, LFP) are utilized as cathode.
What are the advantages of LFP batteries?
Lithium-iron phosphate or LFP batteries, where “F” stands for Fe, are increasingly acknowledged as a sustainable substitute for traditional lithium-ion batteries. The key feature of LiFePO4 batteries is their low toxicity, extended lifespan, exceptional thermal stability and safety profile. LFP battery uses LiFePO4 as the cathode material and graphitic carbon with a metallic backing as the anode. LiFePO4, present in natural minerals such as triphylite and lithiophilite, is more affordable. The reversible process of extracting lithium from LiFePO4 and its insertion into FePO4 has been demonstrated. LFP batteries, devoid of harmful heavy metals like cobalt or nickel, offer significant environmental advantages. They are appealing choices for sustainable energy storage solutions that focus on minimizing carbon footprints and toxic waste production. The unique crystal structure of LiFePO4 allows for the stable release and uptake of lithium ions during charge and discharge cycles (Fig. 1), contributing to its longevity and safety profile.
In contrast to traditional lithium-ion batteries, which can undergo thermal runaway in certain scenarios, LiFePO4 cells are significantly less prone to overheat or fire risks. Furthermore, LiFePO4 batteries demonstrate an extended cycle life with minimal capacity degradation over repeated charge-discharge cycles, making them ideal for applications requiring durability and reliability.
While LFP batteries may have a slightly lower energy density, they make up for this with their slower rate of capacity loss, longer lifespan, and superior safety under high-temperature conditions. The inherent stability of LFP batteries reduces the danger of thermal runaway, a hazardous condition that could result in catastrophic failures, battery fires or explosions. Additionally, since the discharge rate is a percentage of the battery's capacity, using a larger battery with more ampere-hours can achieve a higher discharge rate when the application requires low-current batteries. Thus, LFP batteries are particularly well-suited for emergency power solutions, grid energy storage systems, and electric vehicles. The following table presents a comparison of different lithium-ion batteries.
|
Type of battery/ Features |
Lithium cobalt oxide |
Lithium manganese, oxide |
Lithium iron phosphate |
|
Nominal voltage, V |
3.7 |
3.7 |
3.2 – 3.3 |
|
Operating voltage, V |
3.0 – 4.2 |
3.0 – 4.2 |
2.5 – 3.65 |
|
Minimum discharge / cut off voltage, V |
2.5 / 3.0 |
2.5 / 3.0 |
2.5 / 2.8-3.0 |
|
Maximum charge voltage, V |
4.2 |
4.2 |
3.60 – 3.65 |
|
Volumetric energy density, Wh/L |
High 300 – 600 |
Moderate 300 – 450 |
Moderate 250 – 350 |
|
Gravimetric energy density, Wh/kg |
High 150 – 240 |
Moderate 100 – 150 |
Moderate 100 – 160 (200)* |
|
Cycle Life |
Moderate (500 – 1,000 cycles) |
Low to Moderate500 – 700; 1,000 – 1,200 with hybrid structures |
Very high (2,000 – 5,000 cycles) up to 10,000 cycles* |
|
Charge / Discharge Rate |
Moderate 0.33 to 1C |
Charge: 0.5 C/1CDischarge: standard 1 – 2C, high power 3-5C |
High 1-3C |
|
Safety / Thermal stability |
Moderate LiCoO2 can become unstable if overcharged. |
Good LiMn2O4 is more thermally stable than LiCoO2. |
Excellent LiFePO4 has excellent thermal and chemical stability. |
|
Environmental concerns |
Cobalt is linked to environmental issues. |
– |
Iron is abundant and environmentally friendly. |
|
Typical cost, US $ per kWh |
150 – 250. Most expensive |
100 – 160. More affordable |
80 – 15.Least expensive |
|
Typical Applications |
Ideal where compact size and high capacity are critical, such as smartphones, tablets, laptops, power tools and high-end electric vehicles (EVs). |
Power tools, grid storage, stationary energy systems, some medical devices, and hybrid electric vehicles |
Electric vehicles (especially in budget-conscious and long-cycle life applications), solar energy storage backup power systems and grid backup. |
|
* Estimated after stabilization of mass production. |
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India’s First H2 Electrolyzer Gigafactory
India is prioritizing green hydrogen as a potential solution to decarbonize hard-to-abate sectors such as refinery, ammonia, methanol, iron and steel, and heavy-duty trucking. Ohmium International, headquarters in the United States, aims to establish India as a global hub for green hydrogen. The company's Gigafactory at KIADB Industrial Area, Chikkaballapura, Karnataka, India, is set to produce Proton Exchange Membrane (PEM) hydrogen electrolyzers, starting with an initial manufacturing capacity of approximately 0.5 GW (500 MW) per year, with plans to scale up to 2 GW (2000 MW) per year. Green Hydrogen, characterized by its immense potential, versatility across various business sectors, and zero carbon footprint, is poised to fuel the future.
Links:
www.niti.gov.in/sites/default/files/2022-06/Harnessing_Green_Hydrogen_V21_DIGITAL_29062022.pdf
www.ohmium.com/news/ohmium-launches-indias-first-green-hydrogen-electrolyzer-gigafactory-
India International Science Festival
The 10th India International Science Festival (IISF-2024) took place from November 30 to December 3, 2024, at the Indian Institute of Technology Guwahati. Organized by the Council of Scientific and Industrial Research (CSIR) in collaboration with various ministries and Vijnana Bharati, the event's theme was “Transforming India into an S&T-driven Global Manufacturing Hub”. IISF 2024 hosted a plethora of events and activities for both the public and scientific communities. Highlights included a life-sized artistic model of the moon in honour of India's lunar missions-Chandrayaan-3 (more in Galvanotechnik 11/2023, p.1415 ff), a Mega Science and Technology Exhibition displaying India's progress in defence, space, AI, robotics, and renewable energy, a Young Scientists' Conclave to ignite student interest, and Science Beyond Borders initiative to foster international cooperation. The India Science, Technology & Innovation (ISTI) Portal, a centralized resource for information on fellowships, funding, and startup opportunities within India's science sector, was inaugurated by Dr. Jitendra Singh, Honourable Union Minister of State for Science & Technology. Attracting over 8,000 delegates, 10,000 students, and numerous leading scientific institutions, IISF 2024 served as a pivotal event linking science, society, and innovation, marking India's journey towards becoming a global research, startup, and sustainable development powerhouse.
