In the future battle of automotive energy, will hydrogen fuel cells break out?

Recently, Michael Jost, Chief Strategy Officer of Volkswagen Group, introduced that the pure electric MPE platform currently being developed by the group has begun research on hydrogen fuel cells. Research on fuel cells has re-emerged in recent years, and the industry generally believes that hydrogen fuel cells, although limited by the current environment, may become mainstream in ten years.

People often say: Don't put all your eggs in one basket. This means that when people make plans, they cannot just make one-sided plans, but need to have more alternative plans to reduce risks.

This also makes sense in the pure electric vehicle market. In the pure electric vehicle market, regarding battery technology, there are mainstream lithium battery players such as Tesla, Porsche Taycan and BYD, as well as hydrogen fuel cell car companies such as Toyota Mirai. So which direction is the future of pure electric power?

lithium battery 

The Nobel Prize in Chemistry on October 9 was awarded to three chemists: John B. Goodenough, M. Stanley Whittingham and Yoshino Akira, in recognition of their important contributions to the field of batteries. The lithium battery technology they studied is the basis of electric vehicle battery technology, so some people call the 97-year-old Goodenough the "Father of Lithium Batteries."

As the mainstream in the current market, Tesla, represented by lithium batteries, is undoubtedly a hot commodity in the market.

There are two main types of lithium battery technologies currently used in the pure electric vehicle market: ternary lithium batteries used by Tesla and lithium iron phosphate batteries used by BYD. Let the professor show you the differences between the two.

Ternary lithium battery VS lithium iron phosphate battery 

The life of lithium batteries used in cars is generally determined by the number of cycles. my country stipulates that when the power capacity decays to less than 80%, it must be recycled. According to national regulations, the number of cycles of battery cells - that is, charging and discharging - must reach more than 1,000 times. Generally speaking, the number of cycles of lithium iron phosphate batteries is about 2,000, and the number of cycles of ternary lithium batteries is about 1,000-1,500. Therefore, in terms of the number of cycles, lithium iron phosphate batteries are superior to ternary lithium batteries.

Another lithium battery standard is weight energy density, which is much higher in the Tesla Model S than the lithium iron phosphate battery used in BYD cars. The energy density of ternary lithium batteries is 200Wh/kg, while that of lithium iron phosphate batteries is about 100-110Wh/kg, so ternary lithium batteries are superior.

However, because lithium iron phosphate batteries are relatively more stable, they will only decompose at high temperatures (500-600°C). As ternary lithium batteries are composed of a large number of single cells connected to form a battery pack, and Tesla's battery pack is composed of 7704 cells, how to dissipate heat becomes the biggest problem.

Tesla is the best at preventing so many batteries from overheating and causing short circuits at high temperatures. Tesla uses a liquid cooling system with evenly distributed liquid cooling pipes, which allows each battery cell to be in good contact with the water pipes, thus taking away the heat from the battery cell and achieving good control of the battery cell temperature.

However, the weight of the ternary lithium battery pack plus the cooling system is almost the same as that of the lithium iron phosphate battery in terms of battery density. Since last year, Tesla has announced that it will use a more advanced 21700 battery to replace the current 18650 battery in order to achieve a higher weight energy density.

Ternary lithium batteries and lithium iron phosphate batteries also have a common disadvantage, which is that after a collision, the battery pack will deform, causing a short circuit and fire. Therefore, collision protection of battery packs is also a key research direction for automakers such as Tesla and BYD.

Hydrogen fuel cells 

In fact, as an alternative in the pure electric market, hydrogen fuel cells have been developing very slowly for quite a long time. In recent years, due to the increase in environmental awareness, countries have refocused on this field. According to reports, Geely and Volkswagen have announced plans to deploy hydrogen fuel cells in the domestic market.

Toyota can be considered as a multi-directional automobile manufacturer. It not only has fuel vehicles; in the field of electric vehicles, in addition to the hybrid model Corolla Hybrid, it also has a mass-produced hydrogen fuel car Mirai.

Theoretically speaking, hydrogen fuel cells are 100% environmentally friendly energy. The principle of hydrogen fuel cells is that hydrogen and oxygen undergo a chemical reaction, and the energy generated is converted into electrical energy to drive the car. The "waste" produced by hydrogen combustion is water, which does not pollute the environment at all. Therefore, quite a number of experts believe that hydrogen fuel is the ultimate substitute for gasoline in the future.

Compared with the several hours of charging time for lithium batteries, hydrogen fuel only needs to fill the hydrogen battery in the car, which takes less than 5 minutes. The feeling of charging and going is so refreshing. In addition, official reports show that a fully-filled Toyota Mirai has a range of more than 500km, which greatly alleviates concerns about the range of electric vehicles.

However, the main difficulties with hydrogen fuel currently lie in hydrogen storage, transportation, and the construction of hydrogen refueling stations.

First of all, the storage and transportation of hydrogen require that hydrogen be compressed into hydrogen tanks under high pressure, which is relatively expensive. Moreover, there are certain risks in the process of transportation and storage. Imagine what it would be like to put a gas tank under the seat of a car?

Secondly, due to insufficient investment in hydrogen fuel, most car companies have not invested too much money, so the construction of hydrogen refueling stations is still extremely scarce. According to media statistics, there are 328 operating hydrogen refueling stations in the world, 139 in Europe (56 in Germany), 118 in Asia (91 in Japan), 68 in North America (40 in the United States), and only 12 in China.

So at present, it is easy to buy a car but difficult to refuel it with hydrogen, which will restrict the development of hydrogen fuel cells for quite a long time.

Professor Summary 

In the long run, electric vehicles are definitely the direction of future automobile development. Although lithium batteries are the mainstream now, hydrogen energy as a zero-pollution, environmentally friendly raw material also has considerable potential.

So, which will be the mainstream of automotive energy in the future? Will lithium batteries win, or will hydrogen energy dominate, or will new energy methods be adopted? Welcome to leave a message to express your views.