Lithium-ion batteries or hydrogen fuel cells: what is the difference?
Lithium-ion batteries and hydrogen fuel cells are playing an increasingly prominent role in discussions about the energy transition. Both rely on electrochemical reactions, but they serve different purposes: one stores electricity, the other converts hydrogen into electricity.
This distinction shapes their possible uses, expected performance, and the resources each one requires. Lithium, cobalt, graphite, copper, platinum: every technology depends on its own supply chain, each with its own set of challenges. Comparing the two helps clarify the role each can play in a lower-carbon energy system.
How Do These Two Technologies Work?
The Lithium-Ion Battery: Storing Energy to Release It Later
At its simplest, a battery is a device that stores energy chemically and releases it as electricity on demand. The lithium-ion version is now the most widely used type in electric vehicles and consumer electronics, and for good reason: it delivers a performance-to-size ratio that's hard to match.
In practice, a lithium-ion cell is made up of five main components: an anode, a cathode, a separator, an electrolyte, and two current collectors [1]. During use (discharge), lithium ions travel from the anode to the cathode through the electrolyte. This movement releases electrons, which flow through the external circuit and power the device [1]. During charging, the process reverses: the cathode releases the lithium ions, which return to the anode [1].
This charge-discharge cycle can repeat hundreds, even thousands, of times. In terms of performance, a lithium-ion cell can reach an energy density of up to 330 Wh/kg, compared to roughly 75 Wh/kg for traditional lead-acid batteries [2]. It can also deliver up to 3.6 volts, 1.5 to 3 times the voltage of alternative technologies [2]. This largely explains why they're now found everywhere in modern devices.
The Hydrogen Fuel Cell (PEMFC): Converting Fuel into Electricity
Unlike a lithium-ion battery, which stores energy for later release, a fuel cell works as an electrochemical generator. It produces electricity continuously as long as it's supplied with hydrogen and oxygen.
In a fuel cell, the chemical energy of a fuel, in this case hydrogen, is converted directly into electricity through an electrochemical reaction, without combustion. The most common type for transportation applications is the PEMFC, short for Proton Exchange Membrane Fuel Cell.
Its operation relies on a three-step reaction [3]:
At the anode, hydrogen is split into protons and electrons with the help of a catalyst.
Within the membrane, the protons cross the proton exchange membrane toward the cathode, while the electrons travel through an external circuit. It's this flow of electrons that generates the electric current.
At the cathode, oxygen from the air combines with the protons and electrons to form water and heat, the main byproducts of the reaction.
To generate more power, several cells are stacked together in series, often called a stack [3]. PEMFCs generally operate at low temperatures, usually under 100°C. Their electrical efficiency typically ranges from 40 to 60%, depending on operating conditions and the calculation basis used, particularly hydrogen's lower heating value [4].
What Minerals and Materials Does Each Technology Require?
Comparing lithium-ion batteries and hydrogen fuel cells also means comparing the supply chains that make them possible. These technologies rely on different materials, some of which are considered critical because their production is concentrated in a small number of countries, or because they play a strategic role in key sectors of the energy transition.
The Minerals Behind the Lithium-Ion Battery
The composition of a lithium-ion battery depends largely on the chemistry used in the cathode. In electric vehicles and stationary storage, the most common formulations include NMC (nickel-manganese-cobalt), NCA (nickel-cobalt-aluminum), and LFP (lithium-iron-phosphate) [10]. The anode, for its part, is typically made of natural or synthetic graphite [2].
The supply chain for a lithium-ion battery therefore draws on several distinct mineral resources [5]:
Lithium: an active component of the cathode and the electrolyte.
Cobalt, nickel, and manganese: metals used in certain cathode chemistries, particularly NMC and NCA.
Graphite: the dominant material in the anode.
Copper: used mainly in the anode-side current collector and wiring.
Aluminum: used mainly in the cathode-side current collector.
Not all of these materials carry the same challenges, but several are tied to sensitive supply chains. Batteries already rank among the largest consumers of natural graphite, and demand linked to lithium-ion battery anodes is expected to grow alongside the rise of electric vehicles [5],[9]. Copper also illustrates just how significant these material needs can be: a battery electric vehicle can contain around 83 kg of copper, compared to roughly 23 kg for a conventional internal combustion vehicle [5].
The Materials Behind the Hydrogen Fuel Cell (PEMFC)
The hydrogen fuel cell relies on a different set of materials than lithium-ion batteries. In a PEMFC, one of the most strategic materials is platinum, a platinum-group metal used as a catalyst to speed up the electrochemical reactions.
Platinum is used at both the anode and the cathode, where it helps split hydrogen into protons and electrons, and then facilitates the reaction with oxygen to produce water and heat [11]. In modern systems built for transportation, platinum loadings have dropped sharply compared to earlier generations of fuel cells, though reducing this amount further remains a major focus of research and development [11].
Bipolar plates are another key component of the stack. They handle electrical conduction, gas distribution, and cell separation. They can be made from different materials, each with its own strengths and limits [12]:
Graphite: good electrical conductivity and corrosion resistance, but mechanically more fragile.
Coated stainless steel: a sturdy, generally more affordable material, though it needs a protective coating to limit corrosion.
Titanium: excellent corrosion resistance, but higher cost and more complex to process.
Finally, it's worth distinguishing between the materials in the cell and the hydrogen that powers it. Hydrogen isn't a mineral like lithium, cobalt, or platinum. It's an energy carrier, produced industrially from other energy sources, mainly through natural gas reforming or water electrolysis. Naturally occurring geological hydrogen is also drawing growing scientific interest, largely because of its potential as a low-carbon hydrogen source.
What Are the Typical Uses for Each Technology?
Where the Lithium-Ion Battery Excels
Lithium-ion batteries have become the standard wherever energy density, compactness, and direct electric charging matter most. They now dominate light electric vehicles and consumer electronics [10]. Nearly every battery electric and plug-in hybrid vehicle currently on the market runs on this technology [10].
They also play a central role in stationary battery storage. Most current projects, however, target short-duration storage, often up to four hours, to provide grid flexibility services such as frequency regulation, load shifting, or integrating variable renewable energy [6].
Their most common applications include:
Light electric vehicles: cars, bikes, scooters, and short-distance delivery vehicles.
Portable electronics: phones, laptops, tablets, and other mobile devices.
Short-term stationary storage: residential, commercial, or grid-connected systems.
Urban transit: city buses and fleets operating on predictable routes with scheduled charging.
Where the Hydrogen Fuel Cell Stands Out
The hydrogen fuel cell follows a different logic. It can make sense when the priority is long range, heavy payload capacity, intensive use, or quick refueling. These traits explain the interest in fuel cell vehicles for certain segments of heavy, long-distance transportation [7].
Commonly considered applications include heavy trucks, buses, certain trains, ships, and industrial equipment. In these cases, the potential advantage doesn't come only from the cell itself, but also from the ability to store hydrogen on board and refuel the vehicle faster than a full battery recharge would take.
Beyond transportation, fuel cells can also provide continuous power whenever fuel is available. They're being studied and deployed for certain stationary, industrial, or backup applications, depending on reliability needs, runtime requirements, and hydrogen supply [8].
Their typical applications include:
Heavy and long-distance transport: trucks, intercity buses, trains, or ships depending on the context.
Industrial equipment: forklifts and other material-handling vehicles.
Backup power: telecommunications, data centers, or remote sites.
Stationary applications: continuous or supplementary power generation wherever a hydrogen supply is available.
Table I : Comparison — Lithium-Ion Battery vs. Hydrogen Fuel Cell (PEMFC)
| Criterion | Lithium-Ion Battery | Fuel Cell (PEMFC) |
|---|---|---|
| Principle | Electrochemical storage | Continuous electrochemical conversion |
| Charging / Refueling | Electricity (recharge) | Hydrogen (refuel) |
| Key minerals | Lithium, cobalt, nickel, graphite, copper | Platinum (catalyst), graphite, stainless steel / titanium |
| Energy density | Up to 330 Wh/kg² | Advantage for long distances (high gravimetric density)⁷ |
| Electrical efficiency | — | 40–60% (based on H₂'s lower heating value)⁴ |
| Typical uses | Light vehicles, electronics, short-term storage | Heavy transport, long distance, backup power |
What These Two Technologies Reveal About the Energy Transition
Lithium-ion batteries and hydrogen fuel cells highlight two important realities of the energy transition: low-carbon technologies still depend on materials, infrastructure, and supply chains. Lithium, cobalt, graphite, and copper play a central role in batteries [5], while PEMFCs rely more on platinum, graphite, and structural materials specific to the stack [11]. These differences shape costs, possible uses, and supply challenges alike.
This comparison shows that the goal isn't necessarily to pick one technology over the other, but to understand where each one fits best. Batteries work well for light mobility, electronics, and short-duration storage. Fuel cells, meanwhile, can complement electrification in certain heavy, intensive applications that are harder to serve with batteries alone.
Understanding the links between minerals, technologies, and uses is a first step toward grasping the challenges and opportunities of this transformation. It's precisely this kind of broad exploration that drives Squatex's interest in natural resources and renewable energy.
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References
[1] U.S. Department of Energy. "How Lithium-ion Batteries Work." Energy.gov, Office of Energy Efficiency & Renewable Energy, 7 Jan. 2022, www.energy.gov/energysaver/articles/how-lithium-ion-batteries-work.
[2] Clean Energy Institute. "Lithium-Ion Battery." University of Washington, 2021, www.cei.washington.edu/research/energy-storage/lithium-ion-battery/.
[3] U.S. Department of Energy. "Fuel Cells." Energy.gov, Office of Energy Efficiency & Renewable Energy, 2020, www.energy.gov/eere/fuelcells/fuel-cells.
[4] Barbir, Frano. PEM Fuel Cells: Theory and Practice. 3rd ed., Elsevier, 2020, doi:10.1016/C2018-0-03237-9.
[5] International Energy Agency. "The Role of Critical Minerals in Clean Energy Transitions." IEA, May 2021, www.iea.org/reports/the-role-of-critical-minerals-in-clean-energy-transitions.
[6] International Energy Agency. "Grid-Scale Storage." World Energy Outlook 2022, IEA, 2022, www.iea.org/reports/world-energy-outlook-2022.
[7] International Energy Agency. "The Future of Hydrogen for Transport." IEA, 2021, www.iea.org/reports/the-future-of-hydrogen-for-transport.
[8] International Renewable Energy Agency. "Green Hydrogen: A Guide to Policy Making." IRENA, Nov. 2020, www.irena.org/publications/2020/Nov/Green-hydrogen-A-guide-to-policy-making.
[9] U.S. Geological Survey. "Mineral Commodity Summaries 2022: Graphite." U.S. Department of the Interior, 2022, pubs.usgs.gov/periodicals/mcs2022/mcs2022.pdf.
[10] International Energy Agency. "Global EV Outlook 2023." IEA, April 2023, www.iea.org/reports/global-ev-outlook-2023.
[11] U.S. Department of Energy. "Hydrogen and Fuel Cell Technologies Office Multi-Year Research, Development, and Demonstration Plan." DOE, updated 2020, www.energy.gov/eere/fuelcells/downloads/hydrogen-and-fuel-cell-technologies-office-multi-year-research.
[12] Li, Xianguo. Principles of Fuel Cells. 2nd ed., CRC Press, 2021, doi:10.1201/9780429294499.
