Why are new energy vehicles rising rapidly? A big analysis of the development of power L1022 battery technology

Last year, the global ban on the sale of fuel vehicles announced a timetable, which made people realize that the era of new energy vehicles is coming. Why have pure electric vehicles, plug-in hybrid vehicles, fuel cell vehicles, etc. become the main theme of the future in just a few years? On the one hand, it is the support of global strategies and policies, and on the other hand, it is the continuous improvement of power L1022 battery technology. Longer battery life and shorter charging time are directly related to the commuting needs of users, which has brought new energy vehicles to us. In the future, it will replace traditional fuel vehicles and be inseparable from everyone's daily travel.

Lead-acid battery

Pure electric vehicles first used lead-acid batteries, which were made of lead and its oxides as electrode materials and sulfuric acid solution as electrolyte. This is the power source of most electric bicycles now, and low cost is its biggest advantage. However, because the energy density of lead-acid batteries is low, it brings problems such as large size and small capacity. It cannot meet the control of a car's self-weight, the consumption of driving force, and even the service life of more than 10,000 kilometers per year. Therefore, it cannot be used on a large scale in mass-produced vehicles and was eventually eliminated by automobile manufacturers.

Sealed lead-acid battery pack

Nickel-metal hydride battery

Nickel-metal hydride batteries are very close to our daily life. From the early walkman to the current rechargeable toothbrush and other small appliances, they are very common. The positive electrode is a nickel-metal hydride compound and the negative electrode is a metal hydride. Its energy density and charge and discharge times are significantly improved compared to lead-acid batteries. In addition, the electrolyte is non-flammable, the safety is guaranteed, and the manufacturing process is mature. BYD was the world's second largest nickel-metal hydride battery manufacturer before making cars.

Nickel-metal hydride battery pack

However, because nickel-metal hydride batteries have average charging efficiency, memory effect, and low operating voltage (high-voltage fast charging cannot be used), they are not suitable for a single power source for cars, but are suitable for assisting the engine. Toyota has done the best in this regard. Its hybrid system uses an Atkinson engine + nickel-metal hydride battery pack. The Atkinson engine itself has the advantage of high efficiency in the intermediate speed range, but also has the problem of weakness at low and high speeds. The nickel-metal hydride battery can just solve the problem of insufficient power at start and high speed.

Since the widespread use of lithium-ion batteries, nickel-hydrogen batteries have also tended to be completely replaced in automobiles. For example, Toyota's new generation hybrid system uses a more efficient engine + lithium-ion battery combination. Compared with lithium-ion batteries, nickel-hydrogen batteries do not have advantages in capacity, cycle charging life, and environmental protection. The cost advantage has also been weakened under the vigorous development of lithium-ion batteries. This is why nickel-hydrogen batteries are gradually withdrawing from the automotive field.

Lithium-ion batteries

Lithium-ion batteries are the mainstream choice for new energy vehicles at this stage. Lithium compounds (lithium manganese oxide, lithium iron phosphate, etc.) are used as electrode materials, and graphite is used as negative electrode materials. Its advantages are high energy density, small size, light weight, and high charging efficiency.

General Group Lithium-ion Battery Pack

However, no matter what type, all lithium-ion battery packs will face the natural enemy of low temperature. Although the optimal operating temperature of different lithium-ion battery types varies, the decrease in lithium ion activity after the temperature drops below the optimal range has a greater impact on the cruising range, which is also reflected in our previous tests: the actual cruising range of electric vehicles equipped with lithium-ion battery packs in northern winter is generally only more than 60% of the theoretical cruising range, and at most about 70%.

Test results of the extreme mileage of the Denza EV400

The negative impact of low temperature is not easy to solve from the battery itself, so many car manufacturers have tried to heat the battery pack and added a temperature control system for power lithium batteries. Most brands and models that adopt this approach have some relief purposes, but the actual effect is not an excellent solution to the problem, because the power consumption of some electric vehicle temperature control systems is greater than the loss of low temperature.

The Emgrand EV450 is equipped with the 2.0 version of the ITCS battery intelligent temperature control management system

In this regard, it can be expected that the General Motors Group has the intention to cooperate with the South Korean LG Group to purchase products that are directly equipped with multiple temperature control components inside the battery pack, which can not only dissipate the battery heat as it is now, but also increase the battery temperature in cold weather. The implementation of this technology is worth looking forward to. It is reported that the next round of pure electric and plug-in hybrid new cars of General Motors will use it, replacing the battery packs currently supplied by the Hitachi brand.

Hydrogen fuel cell

Everyone knows that water is finally obtained by burning H2+O2, so hydrogen is an ideal clean energy. As for hydrogen itself, combustion can release a lot of energy, low temperature performance is excellent, and the most important thing is that hydrogen refueling is efficient. It only takes 5 minutes to travel more than 600 kilometers, and this data still has room for improvement. All of the above are far better than existing lithium-ion batteries.

Regarding the investment in hydrogen fuel cell vehicles, Japanese and Korean car companies have long started research and have now invested in their respective countries' markets on a small scale. For example, the Hyundai NEXO hydrogen fuel cell vehicle that the author tested before the Spring Festival has been used in large quantities in the Pyeongchang Winter Olympics and is on the market.

Hyundai NEXO hydrogen fuel cell vehicle

Why is hydrogen, such a good energy source, not promoted? Because it is too difficult to obtain hydrogen with current technology. We all know that hydrogen can be obtained by electrolyzing water, but it consumes electricity to electrolyze water, and then burns hydrogen to finally turn it into water. The power consumption and loss in this process are not as good as directly charging lithium-ion batteries, and the cost is too high. The cost and process are more suitable for extraction from oil and natural gas, but the amount is not large, so fuel cell vehicles are only heard of and difficult to promote.

Graphene battery

Regarding the discussion of power lithium batteries for future new energy vehicles, the most reliable and discussed is graphene batteries. The interpretation of some professional perspectives is translated as: There are two ways to use this material in combination with lithium-ion batteries. One is to use graphene composite materials as a conductive agent for lithium-ion batteries, and the other is to use it directly as a negative electrode. The effect is to increase the activity of lithium-ion batteries, thereby improving the range and charging speed of electric vehicles.

Graphene-carbonized sponge lithium oxygen battery

Graphene batteries can effectively solve the shortcomings of lithium-ion batteries, and the product characteristics are directly linked to the use of new energy vehicle users. The benefits of this material are indeed great, and South Korea's Samsung has also announced that it has mastered this technology, but cost is a major bottleneck. Graphene is not easy to obtain. In the early days, it was a material used in the aerospace field. When and how to reduce costs will be a major problem for this high-quality product to enter the homes of ordinary people. Various automobile manufacturers have not yet announced plans to work in this regard.

Simply put, the working principle of pure electric vehicles is to charge directly with electricity, while hydrogen fuel cell vehicles use H2+O2 to burn (chemical reaction) electricity and water, which is equivalent to burning hydrogen to generate electricity. Both batteries are zero-emission. Electric vehicle lithium-ion batteries have lower capacity density, poor low-temperature activity that affects endurance, and slow charging speed. Hydrogen fuel cell batteries do not have this problem at all, and their working efficiency is much higher. This is why hydrogen is called a high-quality energy source.

Solid-state lithium-ion battery

Solid-state lithium-ion battery, as the name implies, no longer uses liquid electrolyte, but uses solid electrolyte. Its capacity density far exceeds the current mainstream lithium-ion battery, which means that pure electric vehicles have a higher range, even reaching the range of energy-saving gasoline vehicles, and the charging efficiency has also made a qualitative leap compared to the current stage. It is reported that the most ideal charging speed of electric vehicles equipped with solid-state batteries can reach 800 kilometers per minute, which can be said to be the best core component of new energy vehicles.

At this stage, some overseas energy and technology companies, as well as battery manufacturers such as Panasonic, have begun the research and development of solid-state batteries. The only three Japanese automakers involved in this aspect are Toyota, Honda and Nissan, which is due to the promotion of the Japanese national level. Judging from the plans of all parties that have begun to study solid-state batteries, it is expected that there will be breakthroughs in cost, energy density and production and manufacturing in 2020. It will take until 2030 for this research and development result to be implemented and widely popularized in the field of new energy vehicles, which is still a bit far from us. This is also the reason why major automakers did not mention solid-state batteries when announcing their response strategies for the global ban on the sale of fuel vehicles in 2025.

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