Hydrogen fuel cells: An overdue energy change

This is directly related to the larger goal of reducing carbon. Renewable energy will play a crucial role in China's progress towards carbon neutrality. As the country with the largest carbon emission in the world, the power industry accounts for more than half of China's carbon dioxide emission structure, and replacing traditional thermal power generation with renewable energy has become the most direct means of carbon reduction.

To meet the goals of the Paris Agreement, China pledged at last year's climate summit that non-fossil energy would account for 25 percent of its primary energy consumption by 2030, and that the total installed capacity of wind and solar power would reach 12 trillion kilowatts.

In the field of renewable energy represented by photovoltaic, China's strength is almost unrivaled, but the rapid pace of development has also brought the corresponding "sequelae". According to the data of the National New energy Consumption monitoring and early warning center, in 2020, the national abandoned wind power is 16.61 billion KWH, and the national abandoned light power is 5.26 billion KWH.

As renewables replace thermal power generation, there will be a large amount of discarded electricity that needs to be stored, and at the other end of the grid, the hydrogen grid is also struggling with the high cost of electrolyzing water to produce hydrogen. When electricity and hydrogen meet, the energy storage industry of the power grid and the hydrogen production industry of the hydrogen network are very likely to mutual benefit, that is, electrolytic hydrogen production using renewable energy generation. This would solve many of the problems we are currently facing.

Since the marginal cost of renewable energy is close to zero, its pricing is lower than the market pricing of other electricity, and even can reach negative pricing, the use of renewable energy for hydrogen production will be highly economic advantages.

Second, the "lithium" dilemma

In the new energy system represented by "renewable energy power generation, UHV transmission, and new energy vehicle electricity", there are also hidden worries.

This hidden concern first appeared in the application of lithium battery technology, after more than ten years of rapid running, the battery began to struggle.

The endurance bottleneck of new energy vehicles is mainly affected by electricity. On the surface, the power can be boiled down to a matter of "quantity" : as long as enough batteries are installed, enough power can be generated to improve battery life. If a 60kWh battery can run 400 kilometers, wouldn't a 150kWh battery be able to easily break through 1,000 kilometers?

Unfortunately, the improvement of battery life is not a simple addition, subtraction, multiplication and division. According to the current mainstream energy density calculation, a 60kWh power battery pack weighs about 400kg~500kg, accounting for about 30% of the weight of the vehicle. As the weight increases, the battery will face the problem of diminishing marginal returns. That is, increasing the battery will also increase the weight and resistance of the electric vehicle, when the battery load is too large, most of the power will be used to drag the heavy battery pack to run, rather than contribute to the battery life of the electric vehicle, lithium battery car endurance ceiling also appears.

If you want to improve the endurance of the current electric vehicle from the power, it is no longer feasible to start from the "pile volume", and only "improve the energy density" can go. Specifically, there are four main lifting ways, respectively, positive lifting, negative lifting, electrolytic liquid system lifting and packaging technology upgrading.For positive materials, energy density and safety are like two ends of a seesaw, and cannot be both. Commonly used cathode materials are lithium cobaltate, lithium iron phosphate, lithium manganate, ternary lithium, etc. Each material must make a trade-off between energy density and safety.

Lithium iron phosphate has the strongest battery safety because of the addition of stable but bulky iron, but it also seriously affects the endurance of electric vehicles; The most mature cathode material is lithium cobaltate, but the corresponding energy density and safety are ordinary; "Radical" ternary lithium has the best energy density and the longest battery life, but frequent safety accidents also make consumers look backward.

At present, the development progress of positive electrode materials is still stopped at the high-nickel ternary lithium solution, and the technical solution of higher energy density is still in the laboratory.

The bottleneck of the negative electrode material is similar to that of the positive electrode material, so far no optimization scheme has been found that can replace the existing material. The anode material of lithium battery is graphite, and the most potential material to replace graphite is silicon material, but the latter has fatal problems such as large expansion coefficient.