Hydrogen fuel cell VS lithium ion battery

The clear main task of each successful energy innovation in human history is that upgrade the number of energy density. For example, the energy density of coal is 160 times higher that of wood, and the energy density of petroleum is 2 times higher that of coal. Only when the new energy gets the overwhelming advantages on energy density can it reverse the inertial application of traditional energy with long-time complete underlying network and industrial auxiliary. The 10-times principle is carried out by Grove in IT, the founder of INTEL, which means that once the extremely new technology shows up, it is overwhelming. For instance, gasoline car was invented 20 years later than electric car, with immature early technology, but it still quickly replace the electric car for high energy density.

Analysis of hydrogen fuel cell and lithium ion battery

Electric car are widely promote all over the world in recent years, but the proportion is still less than 1%, because the electric car before violated the purpose of upgrading energy density during innovation. The extremum energy density of latest generation lithium ion battery car is only 1/40 of that of gasoline. It is difficult to make progress at 10-times rate in battery industry. However, fuel cell totally changes this condition. Based on hydrogen as raw material, it has three times basic energy density as gasoline, the work efficiency of electromotor is two times as internal combustion engine, and its actual density is 6 times as gasoline. Its advantages are obviously. Dated back from the evolutionary history of energy resources in the past one hundred years, we can found out that it is essentially modification history of carbon hydrogen ratio. The more content of hydrogen, the higher energy density is. Resources transformation from carbon to hydrogen is trending. Therefore, it is potential that hydrogen fuel cell will be the next essential energy power.

The major performances of automobile are endurance, charging/hydrogen charging time, output power, safety performance, etc. The energy density of fuel cell is far higher than lithium ion battery. Fuel cell has advantages on capacity, fast charge and endurance. Even compared with Tesla lithium ion battery, it still has great performance. However, it doesn’t have high power density. The maximum output power depends on auxiliary power battery system. There is little difference between fuel cell and lithium ion battery on max speed and accelerating index per kilometer. In order for further analysis, let’s take gasoline car with 2L gas displacement, 45 degree lithium ion battery car and fuel-cell vehicle with 100KW output power as examples below.

Energy density

As one of storage batteries, lithium ion battery is a closed system. Battery is a carrier of energy, cannot work without charging. Its energy density is depended on electrode materials. In order to increase energy density, we need to upgrade anode materials from lead-acid, Nickel-based to lithium, because the energy density of cathode materials is much higher than that of anode materials. However, Li is the metal element with smallest atomic weight. The only anode material that is better than Li ion is lithium electrode with 1/4 the energy density of gasoline. Besides, lithium electrode has technological difficulty on commercialization and hardly makes process within dozen years. Therefore, it can only upgrade the energy density from 160Wh/KG at present to 300Wh/KG, due to theory bottleneck. Even when it makes this come true, it is only 1/120 of fuel cell. It’s doomed to be a failure at the beginning.

Volume energy density

The major shortcoming of hydrogen material of fuel cell is lack of high volume energy density. This issue tends to be solved by elevating pressure at present. According to the pressure mode of 700 barometric pressures, its volume energy density is 1/3 of gasoline. As for 300-kilometer running, the hydrogen tank volume of fuel cell is 100L, weight is 30KG, the equivalent fuel tank of gasoline car is 30L. Luckily, the volume of electromotor is 80L smaller than internal combustion engine, so they have similar total volume. There are two kinds of mainstream technology techniques for ternary and lithium iron phosphate of lithium ion battery vehicle. The representative companies are Tesla and BYD. Ternary has higher energy density but poor safety performance, and needs auxiliary protective device. The volumes of these two kinds of batteries are 140L and 220L, and weight is 0.4 ton and 0.6 ton for 300-kilometer running. Both of them are higher than fuel cell. If hydrogen storage alloy and liquid hydrogen storage technology under low temperature can make through, the volume energy density of fuel cell will increase 1.5 times and 2 times separately. Its advantages will be more obviously.

Power density

Fuel cell is essentially a chemical power system of hydrogen raw material, so its output power is stable. In order to upgrade discharging power, it needs a power battery system, such as Toyota Mirai, auxiliary NI-MH battery. As an open power system, the energy come from external input, the auxiliary NI-MH battery has no issue of energy storage, which can meet the requirement under 5-8 ℃, have low requirement on cycle life, and have little service restrictions during actual application. Although the design discharging efficiency is high, there are many service restrictions in order to protect the cycle life of lithium ion battery. It cannot discharge at high rate after fully charging. Fast discharge must be within 0-80%. However, the cycle life in laboratory still decreases into 600 times discharging on 5C, and lessens into 400 times during actual application. For example, the actual discharge rate of Telsa is 4C, even if its maximum power is 310KW. As a sealing energy storage system with low energy density, the high power discharging and high endurance mileage cannot be compatible, unless make a substantial increase on battery weight. The weight of battery pack is nearly half ton after using ternary battery with the best energy density at present.

Safety performance

Safety performance is also very essential for motor vehicles. As a sealing energy storage system, high energy density and safety performance cannot be compatible, or the battery will explode. Therefore, during mainstream technics, the safety performance of Lifepo4 battery with low energy density is good, and it won’t begin to decompose only when the temperature is 500-600℃, so there is no need to prepare so many protective auxiliary equipment. The ternary battery of Telsa has high energy density, but no high temperature resistance, it will decompose at 250-350℃ with poor safety performance. The solution is connecting over 7000 batteries in parallel, decreasing single battery leakage and explosion. Besides, it also needs a complicated protective device. There is no casualty in the several accidents before due to Telsa safety design, but the fire battery reflects its instinctive poor safety performance.

Because hydrogen is inflammable and explosive, fuel cell using it as raw material will affect the safety performance. However, compared with fuel vapor and natural gas, they are both popular flammable gas for cars, and the safety performance of hydrogen is better. Nowadays, hydrogen storage device is made from carbon fiber material and there is no wrong with the battery during multi-direction intersection detection at 80KM/h. Even if the car accident leads to leakage, it is difficult for hydrogen to explode because it needs high concentration for explosion but it burns at the beginning. Besides, hydrogen has light weight. The burning hydrogen goes up after leak out the device, which protects the car and passengers. On the contrary, gasoline is in liquid state, lithium ion battery is in solid state. Neither of them can be easy to go up in air. They will burn under the car, and then the car will scrap quickly. The storage and transportation of hydrogen are similar to LNG, and need more pressure. As commercialization promoted, its safety performance can be control better and better.

The cost of battery vehicle is divided into whole-car cost, raw material cost and assembly cost. At present, the main shortcoming of fuel cell is the cost. As for the development, the cost can be decrease because of the rapid technology development and commercialization. Given that the cost of power grid expansion, the total assembly cost of lithium ion battery will be higher than that of fuel cell. The calculation is as follow:

Whole-car cost

The cost of engine is the most different part of whole-car cost between the car of lithium ion battery, fuel cell and gasoline. The engine cost of a 2L gasoline car is around 30,000 yuan, which may have little difference in the future. Recently, the cost of lithium ion battery is 1200yuan/kWh, and it may decrease to 1000yuan/kWh in the future. The battery cost of a 45 degree electric vehicle is 45000 yuan. The major costs of fuel cell are battery pack and high pressure storage tank. The 100KW battery pack costs 100,000yuan now. It is predicted that the cost per unit will decrease to 30dollars/KW, which is 20,000yuan in RMB, after annual output for 500,000 pieces. The hydrogen storage tank costs 60,000yuan now. It may decrease to 35,000yuan, and the total cost is 55,000yuan. The costs of these three kinds of power system will have little difference for a long time. The whole-car cost is not the core issue.

Raw material

A 2L gasoline car consumes 10L gasoline per kilometer. Gasoline costs 5.8yuan per liter, so it costs 58yuan in total. The power consumption per kilometer of lithium ion battery car is 17kWh. it costs 0.65yuan/kWh, and 11yuan in total. The fuel cell consumes 9m3hydrogen per kilometer. The major hydrogen production methods are water electrolysis or chemical reaction, such as producing hydrogen by coal, natural gas, etc. The cost of water electrolysis is electricity, 5kWh and 1 m3 at average. It costs about 3.8yuan/ m3. You can electrolyze at hydrogen refueling station, so as to save the money for transportation. If adopt fossil energy for mass production. The cost of hydrogen made by coal is the cheapest, and is about 1.4yuan/ m3. North America can make use of inexpensive natural gas, which costs 0.9yuan/ m3. Take the cost of making hydrogen by coal as standard, the cost of raw material per kilometer is 12.6yuan. It is little different from that of lithium ion battery.

Assembly cost

The costs of hydrogen refueling station, petrol station, charging station are divided into land cost, facility cost and construction cost. Their main differences are on facility cost. Petrol station normally costs 3000,000 yuan, charging station costs around 4300,000 yuan, while hydrogen refueling station is predicted 15000,000 yuan based on Japan recent standard. Comparatively, the cost of hydrogen refueling station is totally 10000,000 yuan or so higher than the others. According to 15-year depreciation, if sales volume of hydrogen is 10 million cubic meters, cost of depreciation will be 0.1yuan/m3. Normally, small-scale hydrogen is transported by tank car, of which transporting cost is 0.44yuan/m3. Larger-scale hydrogen can transport by pipeline, and then the cost will lessen to 0.23yuan/ m3.

Although the assembly cost of lithium ion battery is low relied on completed power grid system, it needs to expand in the future, because the rest of recent power grid will be ran out after large-scale popularization. Charging station puts the assembly cost on power grid, so remember to pay attention to the cost of power grid when calculate the cost of the whole industry chain. Charging station of commercial operation will meet the standard of 1-hour fast charge at least. The power of charging station made by 10 charging piles is 600 KW, which is the same as hundreds of household electrical load and has strong effect on the power grid. It needs to invest more 1.2 million yuan to expand the power grid. However, annual sales volume is only 930,000 kWh. Calculate by 0.65yuan/kWh and based on prediction of 15-year depreciation, the selling price needs to increase 0.18yuan/kWh over the cost.

Selling cost

The sales network of petrol station is developed. The profit per hour can be the calculating standard of reasonable return for filling station. The price difference of hydrogen refuel station is 0.51 yuan per cubic meters, while lithium ion battery is 4.9 yuan per kWh, which is against the extension of lithium ion battery car. At present, the upper limit of service charge in charging station set by the government is 0.4 yuan/kWh with large subsidy. However, there is not any industries can develop by long-time subsidy. If cannot upgrade the charge efficiency of lithium ion battery in the future, the enterprise profit will be far lower than petrol station and hydrogen refueling station. Without reasonable return, the investor won’t incent the promotion of charging station due to the high cost in city, so that the industry cannot develop normally. The energy density of lithium ion battery is so low that is challenge a lot for cycle life technique if force to pursuit high charging efficiency. Even if fulfill 3-minute fast charge, the power of related single charging pile needs to reach 1200 KW. Every charging station requires ancillary transformer substation of 110 KV. The investment will be 50 million yuan, the station will cover 5000 ㎡,  residential buildings are not allowed within 300 meters around, and it is a huge implementation  challenge in coastal big city.

Total cost

All in all, the costs per hundred kilometer of gasoline car, lithium ion battery car, fuel-cell vehicle before and after commercialization are 58 yuan, 83 yuan, 23 yuan and 20 yuan. The difference in sales cost has a high proportion on total cost. Given that the investment of charging pile is 1/3 of hydrogen station, the composite cost is 37 yuan even lessen the profit to 1.4 yuan per hour. Fuel-cell vehicle has obvious advantage of long-run cost due to the high energy density of fuel cell. Fuel cell costs lower than any other batteries under the same commercialization state.

One of the most important parts of new energy vehicle development is environmental protection, which is more essential in our country. Nowadays, the air pollution in our country is getting worse and worse. Besides, petroleum import trade interdependence reaches 60%. 85% petroleum needs to pass Malacca controlled by America. Energy security becomes the biggest shortcomings in our national security. Therefore, in order to lessen the import interdependence, the government pays a lot subsidy for new energy vehicle. Let’s compare the differences on energy conservation, environmental protection, and resource constraint as follow:

Energy conservation and environment protection

The most economical method for producing fuel cell raw material is coal-making method. The electric power of lithium ion battery in our country is also mainly from coal power generation. Therefore, both of these materials are from coal, carbon emission transfer to the last process. We need to check the energy conversion efficiency, so as to figure out whether they are environmentally friendly. Nowadays, lithium ion battery car consumes 17 kWh per hundred kilometers, which runs out 6.8 kilo coal. Fuel cell consumes 9 m3 per hundred kilometers, lose 20% during shipment, which runs out 7.3 kilo coal. Gasoline car consumes 10L petrol, and its carbon emission is equivalent to 10 kilo coal. The energy-saving effect of new energy vehicle is not apparent. Its core value is to transmit the primary energy consumption from petroleum to coal with abundant resources, which can help a lot on energy security. As for environmental protection, fuel cell car hardly has exhaust gas emission, and lithium ion battery car only has little emission. The pollution of this industry is mainly on the last process. Compared to handling the exhaust gas emission, the pollution control on the last process will be easier. All in all, fuel cell has lower pollution than any other energy in the whole industry chain and can be regarded as the best environmentally friendly energy.

Resource constraint

Fuel cell needs noble metal platinum as catalyst, which may lead to resource constraint. In 2015, the global demand of platinum is 270 ton. It is widely used in catalyst of automobile exhaust cleaning, jewelry and industry. The individual proportions are 44%, 34% and 22%. The platinum consumption of Mirai bicycle is about 20g, which is 10-15g higher than gasoline car. If the annual output of fuel-cell vehicle occupies 5% of the global one, the annual consumption growth is about 56 ton, which seems make great shock. However, if the annual output of lithium resources is 80,000 ton, the corresponding annual output with 40,000 ton will shock a lot, which can be proved by the price spikes of Li ore in this year. The medium term objective of Toyota is lessening the consumption of platinum by75%, and realizing the recycle of catalyst. If one of the goals above is achieved, the resource constraint of platinum can be nearly solved.

Commercialization state

As for commercialization, there is a five –year gap between fuel-cell car and lithium ion battery car. It still belongs to commercialization state at present, and may make great progress in 2020. The countries with global leading technology are Japan and America at present, especially Japan is nearly the only country has great technique on passenger vehicle. Mirai that put into mass production in 2015 has basically meets the initial standard of commercialization. Comparatively, it is lack of someone to lead in domestic battery industry. Only Beiqi Foton and SAIC has produced fuel-cell motor coach on Olympics in 2008 and World Expo in 2010, but they are still on demonstration stage. As the development of fuel cell technology, our country can make great progress quickly with a large economy.

Energy in the future and reconstruction of industrial system

Recently, the global energy is from the edge energy of the sun'sspecial fusion, and the total output power is 1.8*1013. According to Kardashev scale, it is still at the state of planetary civilization. In order to satisfy the initial requirement of 1016 star civilization, it is necessary to realize controllablespecial fusion. At that moment, 1 kilo isotope of hydrogen can produce over 100 million kWh power, which is equivalent to 1 kilo sea water to 300L petroleum. Water becomes petroleum is not a dream any more, and energy is not the issue stuck the human development any more. The cost of producing hydrogen by water electrolysis will be lower, and controllablespecial fusion and hydrogen energy will become the final combination of energy structure. Then petroleum can get out of the fuel area, the cost of different kinds of petroleum-based materials will lessen to an unbelievable price, which can make infinite possibility to the reconstruction of industrial system in the future. That will be a wonderful era.

Throughout human history, every energy revolution will result in the reconstruction of the whole industrial system, and even changing the global leading country. The first industrial revolution made England become the leading country in the world, while the second industrial revolution made America. If fuel-cell car completely replaces the petroleum car in the future, the whole industrial system founded by petroleum will be subverted, the technical superiority accumulated by the developed country in the last 200 years will shorten rapidly, and this may be a good chance for us to surpass. When we catch this historic opportunity, it is probable for us to become the leading country in the next industry system. Japan is the first countries to invent lithium ion battery, so it is worthwhile for us to consider the reason for Japan giving up R & D of lithium ion battery car but dedicating to fuel-cell car.