Analysis: the rapid rise of new energy vehicles and the development of power battery technology

From a practical point of view, the only new energy vehicles that can be bought after the 2025 fuel ban are new energy vehicles. How a car's battery is important. As the battery development described in this article, the old type of battery has gradually become history. Some of the new battery technology is still in the conceptual stage, and some will come to everyone as long as they overcome problems such as technology and cost.

Last year, when the global timetable for banning fuel vehicles made people aware that the era of new energy vehicles was approaching, why did pure electric vehicles, plug-in hybrids, fuel cell vehicles, and so on become the theme of the future in just a few years? On the one hand, it is the support of global strategies, policies, and other aspects. On the other hand, the continuous improvement of power battery technology, longer life and shorter charging times, which directly affect the user's commuting needs, have brought new energy vehicles to us. In the future, it will also replace traditional fuel trucks, and it is inseparable from everyone's daily travel. So there is what people say: "The development of new energy vehicles is the development of battery technology. "

Why are new energy vehicles rising rapidly? Analysis of the Development of Power Battery Technology

Lead acid batteries

Pure electric vehicles were first used in lead-acid batteries, lead and its oxides were made as electrode materials, and sulfuric acid solution was used as an electrolyte. This is now the power source for most electric bicycles. Low cost is its greatest advantage. However, because of the low energy density of lead-acid batteries, which brings about problems such as large size and small capacity, it can not meet the control of a car for self-weight, the consumption of driving forces, and even the service life of more than 10,000 kilometers per year. Can not be used on a mass production vehicle, It was eventually eliminated by car manufacturers.

Why are new energy vehicles rising rapidly? Analysis of the Development of Power Battery Technology

Sealed packaged lead-acid batteries

Nickel hydride batteries

Nickel-metal hydride batteries are very close to our daily life. It is very common to hear small electrical appliances such as charging toothbrushes from the early days. It is extremely nickel-metal hydride compounds, negative metal hydride, and its energy density, charging and discharging times. Compared with lead-acid batteries, there is no small increase, In addition, the electrolyte is non-flammable, safe, and the manufacturing process is mature. BYD is the second largest nickel-metal hydride battery manufacturer in the world before building a car.

Why are new energy vehicles rising rapidly? Analysis of the Development of Power Battery Technology

Nickel hydrogen battery pack

However, because nickel-metal hydride batteries have general charging efficiency, charging and memory effects, and low operating voltage(can not use high-voltage fast charging), they are not suitable for a single power source for automobiles and are suitable for auxiliary engines. The best thing to do in this area is Toyota. Its hybrid system uses the Atkinson engine + nickel-metal hydrogen battery pack. The Atkinson engine itself has the advantage of an efficient intermediate speed range, but it also has low speed and high speed problems. The nickel-metal hydride battery can just solve the start-up and high-speed power shortage of a major boost.

Why are new energy vehicles rising rapidly? Analysis of the Development of Power Battery Technology

After being widely quoted from lithium batteries, nickel-metal hydride batteries have also been completely replaced on cars. For example, Toyota's new-generation hybrid system uses a more efficient engine + lithium battery combination. Compared with lithium batteries, the capacity of nickel-metal hydride batteries, the life of cycle charging, and the Environmental Protection angle are not dominant, and the advantage of cost is also weakened under the vigorous development of lithium batteries. This is why nickel-metal hydride batteries gradually withdraw from the automotive field.

lithium cell

Lithium batteries are the mainstream choices for new energy vehicles at this stage. Lithium compounds(lithium manganate, lithium iron phosphate, etc.) are used as electrode materials, and graphite is a negative electrode material. Its advantages are high energy density, small size, light weight, and high charging efficiency.. The main factors that determine the type or performance of lithium batteries are the materials at the two poles of the battery, of which the materials at the positive pole are the key at this stage, such as the mainstream lithium iron phosphate, lithium cobalt oxide in ternary materials, and nickel cobalt manganese. There are differences in capacity, cost, low temperature charging and discharging, safety and other dimensions.

Why are new energy vehicles rising rapidly? Analysis of the Development of Power Battery Technology

General Group lithium batteries

However, regardless of any type, all lithium batteries will face the "natural enemy" of low temperature. Although the optimal operating temperature of different lithium cell types is somewhat different, the activity of lithium ions that is lower than the optimal range is accompanied by a decrease in the activity of lithium ions, which has a greater impact on the range of endurance. This is also reflected in our previous tests: Electric vehicles carrying lithium batteries, The actual use of endurance in the northern winter can generally only reach more than 60 years of theoretical renewal, up to about 70 miles.

Why are new energy vehicles rising rapidly? Analysis of the Development of Power Battery Technology

Test results of EV 400 limit mileage

The negative impact of the low temperature is not easy to solve from the battery itself, so many auto manufacturers have tried to warm up the battery pack and add a temperature control system for the power cell alone. Most of the brand models that use this approach have a certain mitigation effect. However, the actual effect is not an excellent solution, because there are some electric vehicle temperature control system power consumption, more than the loss of low temperature.

Why are new energy vehicles rising rapidly? Analysis of the Development of Power Battery Technology

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

What can be expected in this regard is that GE is already interested in working with LG Group of South Korea to procure products that directly equip multiple thermostat components inside the battery pack, not only to cool the battery as it is today, but also to raise the temperature of the battery in cold weather. The landing of the technology is to be expected, and it is understood that GM will use the next round of pure and plug-in hybrid cars, replacing batteries now supplied by Hitachi's brand.

Hydrogen fuel cells

Everyone knows that H2 + O2 burns the final water, so hydrogen is a very good clean energy. As far as hydrogen itself is concerned, combustion can release a lot of energy, perform well at low temperatures, and the most important hydrogenation is high efficiency. Hydrogen can travel more than 600 kilometers in just 5 minutes, and this data still has room for improvement. All these are far better than the existing lithium batteries.

Why are new energy vehicles rising rapidly? Analysis of the Development of Power Battery Technology

With regard to hydrogen fuel cell vehicle input, Japanese and Korean car companies have long begun research and have now invested in their respective countries 'markets in a small area, such as the modern NEXO hydrogen fuel cell vehicle that I tried to drive before the Spring Festival. It has been widely used in the Pingchang Winter Olympics and sold on the market.

Why are new energy vehicles rising rapidly? Analysis of the Development of Power Battery Technology

Modern NEXO hydrogen fuel cell vehicle

And hydrogen is such a good energy source, why not promote it? Because it's hard to get hydrogen with the current technology. Everyone has learned that electrolytic water can produce hydrogen, but it consumes electricity to electrolyze water, and then burn hydrogen and eventually turn into water. The power consumption and loss in this process are not as good as charging lithium batteries directly. The cost is too high. The more appropriate cost and process are extracted from oil and natural gas, but the amount is not large, so the fuel cell car "only heard its name and it is difficult to promote it."

Why are new energy vehicles rising rapidly? Analysis of the Development of Power Battery Technology

Graphene batteries

For the future of the new energy vehicle power battery discussion, the most reliable, most discussed is graphene batteries, some professional interpretation of the "translation" is: using this material combined with lithium batteries have two ways to use. The first is to use graphene composite material as a conductive agent for lithium batteries, and the second is to use it directly as a negative electrode. The effect is to increase the activity of lithium batteries, thereby increasing the range and charging speed of electric vehicles.

Why are new energy vehicles rising rapidly? Analysis of the Development of Power Battery Technology

Graphene-carbonated sponge lithium oxygen battery

Graphene batteries can effectively solve the short plates of lithium batteries, and the product characteristics are directly linked to the use of new energy car users. The benefits of this material are indeed great, and South Korea's Samsung has announced that it has mastered this technology, but the cost is a major bottleneck, graphene is not easy to obtain, and the early days were used as a material in the space field, when and how to reduce costs. It will be a major challenge for the premium product, which has yet to be unveiled by any automaker.

Why are new energy vehicles rising rapidly? Analysis of the Development of Power Battery Technology

In simple terms, the principle of pure electric vehicles is "charging direct electricity", and hydrogen fuel cell vehicles are H2 + O2 "firing"(chemical reaction) electric energy and water, which is equivalent to "burning hydrogen" to generate electricity. Both "batteries" are also zero-emission. Lithium batteries in electric vehicles have a smaller density of capacity, lower temperature activity, and slow charging speed. Hydrogen fuel cells are completely free, and their working efficiency is much higher than that of other batteries. This is why hydrogen is known as a good source of energy.

Lithium solid batteries

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

Why are new energy vehicles rising rapidly? Analysis of the Development of Power Battery Technology

At this stage, some overseas energy and technology companies, as well as battery manufacturers such as Panasonic, have started the development of solid-state batteries. Automakers involved in this area are only Toyota, Honda and Nissan's three major Japanese car companies. This is due to Japan's national level. Booster. A breakthrough in cost, energy density and manufacturing is expected by 2020, according to plans already under way to study solid-state batteries. It will not be until 2030 that this development will be launched and widely used in new energy vehicles, which is still a bit far from us. This is why major car companies did not mention solid-state batteries when they issued a response strategy for the global ban on fuel vehicles in 2025.

Why are new energy vehicles rising rapidly? Analysis of the Development of Power Battery Technology

Many car companies and even new car forces have released new energy plans for the future. Please wait for more information.

summary

At the big end, environmental protection seems to be a major direction in the world. Electric energy is also an essential energy source for ordinary people's lives. Therefore, new energy vehicles that use electricity as a fuel are the easiest to achieve and the transition is the most smooth. From a practical point of view, after the 2025 ban on the sale of fuel vehicles, the only new energy vehicles that can be bought are new energy vehicles. How the battery of a car is crucial. As the battery development described in this article, the old type of battery gradually became history. Some of the new battery technology is still in the conceptual stage, and some will come to everyone as long as they overcome problems such as technology and cost.

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