Battery and Fuel Cell Technologies

Most of the content on this page comes from the course of Didier Dalmazzonne, although I may have added other information on top.

Battery Overview

The first battery was created by Volta in 1782.

Lead-Acid Battery

Invented by Gaston Planté in 1859, the lead-acid battery represents around 80% of installed battery capacity.

The overall reaction is:

$$Pb(s) + PbO_2(s) + 2H_2SO_4(aq) \rightarrow 2PbSO_4(s) + 2H_2O$$

Comparison of Battery Technologies

Battery type	Number of cycles (100% discharge)	Cost (€/kWh)
Li-ion	4000	500
Lead-acid	800	100
NaS	4500	450
Zebra	4500	450
Vanadium	20 years	450
Zn/Be	4500	650

Lithium-Ion Technologies

Battery type	Cathode	Anode	Cell voltage	Cost	Energy density	Cycle life	Discharge rate
LCO	Li Co Oxide	Graphite	3.6 V	Medium	500 Wh/L	Short	Up to 3C
LFP	Li Fe Phosphate	Graphite	3.2 V	Low	180 Wh/L	Medium	Up to 25C
Li-NCA	Li Ni Co Alumine	Graphite	3.6 V	Low	500 Wh/L	Short	Up to 3C
Li-NMC	Li Ni Mn Co	Graphite	3.7 V	Medium	500 Wh/L	Medium	Up to 3C
LTO	Ni Co Alumine	Li Ti Oxide	2.4 V	High	120 Wh/L	Long	Up to 10C

Hydrogen Overview

Hydrogen Today

Data

• World production: 75 Mt
• Energy equivalent of H₂ production: 0.2 Gtoe/year
• Oil production: 4.4 Gt/year
• World primary energy consumption: 14.5 Gtoe/year
• Hydrogen produced by fossil-fuel reforming: 95%
• Fossil-fuel reforming and gasification: 1 GtCO₂/year
• Human CO₂ emissions: 35–40 GtCO₂/year

Main Current Uses of H₂

• Oil refining: 44%
• Ammonia for fertilizers: 38%
• Food industry: 9%
• Methanol and chemicals: 8%
• Space propulsion: 1%

Pros and Cons

Pros

• Raw material abundant and 100% regenerated
• High energy density per unit of mass
• Variety of sources, production methods and uses
• No direct greenhouse effect, but hydrogen interacts with other molecules which can contribute to an increase in the greenhouse effect

Cons

• Cost
• Low density per unit of volume (40 kg/m³ compared with approximately 800 kg/m³ for oil)
• Difficult to store
• Lack of dedicated infrastructure and distribution networks
• Risk acceptance

Converting Hydrogen to Energy

There are two main ways of converting hydrogen into energy:

• Direct combustion
• Fuel cells

Main Hydrogen Fuel Cell Technologies

Type	Electrolyte	Temperature (°C)	Fuel	Efficiency	Power	Maturity
Alkaline	KOH	50–200	Industrial H₂	65%	10–100 kW	Mature
Phosphoric Acid	H₃PO₄	180–220	H₂	35–40%	10 MW	Commercial
Proton Exchange Membrane	Solid polymer	30–100	H₂	35–40%	100 W–500 kW	Commercial
Molten Carbonate	Li₂CO₃, K₂CO₃, Na₂CO₃	600–700	H₂	50–60%	100 MW	Development
Solid Oxide	ZrO₂, Y₂O₃	800–1050	H₂, CO₂, CH₄	50–65%	100 MW	Development

Proton Exchange Membrane

A proton exchange membrane (PEM) is a semipermeable membrane designed to allow protons to pass through while blocking reactants such as H₂ and O₂.

It can be used in a fuel cell according to the following reaction:

$$2H_2 + O_2 \rightarrow 2H_2O + \text{heat} + \text{electrical energy}$$

Perspectives for Hydrogen

Hydrogen production would need to be multiplied by approximately 12 to meet 20% of today’s energy requirements.

Hydrogen Production Costs

According to DOE data from 2013:

• Large-scale SMR: 1.5 $/kg
• Small-scale SMR: 3–6 $/kg
• Electrolysis: 6–15 $/kg
• Carriage costs: 1.25 $/kg
• Global hydrogen costs: 22–135 $/GJ
• Global oil costs: 7 $/GJ

Conclusion

Hydrogen is regarded as a solution for long-term storage of energy produced from low-carbon sources.