lithium ion battery 18650 price

Ternary lithium ion battery 18650 may replace solid-state batteries, which is the future direction of power lithium battery research and development

Power batteries are the core components of electric vehicles, and their performance plays a decisive role in the overall performance of electric vehicles. In the era of rapid development of electric vehicles, batteries with more powerful performance are undoubtedly the endless research and development targets of major car companies and battery manufacturers.

In the past, domestic electric vehicle giant BYD abandoned lithium iron phosphate batteries and turned to ternary lithium ion battery 18650. Later, Watma had a wrong technical route and the company fell apart. This is precisely because lithium iron phosphate batteries cannot keep up with the pace of electric vehicle development in terms of performance. Driven by the rigid demand for high-range electric vehicles, ternary lithium ion battery 18650 with higher energy density potential have replaced the once widely used lithium iron phosphate batteries and become a necessary process in the development of electric vehicles.

However, the development of technology cannot remain unchanged. With the continuous expansion and maturity of the electric vehicle field, the demand for battery capacity density of electric vehicles is also increasing.

Earlier this year, Fisker Automotive Company of the United States released a new solid-state battery technology. It is reported that the energy density of this technology is 2.5 times that of conventional lithium-ion batteries, which can increase the mileage of electric vehicles to more than 500 miles (about 804 kilometers). What is even more amazing is that its charging time only takes 1 minute, which is even faster than the refueling speed of traditional fuel vehicles.

Subsequently, many global car companies and battery manufacturers also released research and development progress related to solid-state batteries. At present, Toyota, Panasonic, Samsung, Mitsubishi, BMW, Volkswagen, Hyundai, Dyson and other companies are stepping up the layout of solid-state battery technology reserves. So far, the topic of solid-state batteries "crushing" lithium ion battery 18650 has become a hot topic of debate in the new energy vehicle industry.

Recently, the Chinese Academy of Sciences announced that the "All-Solid-State Battery" project of the Nano-Pioneer Project led by it has passed the acceptance. This technological advancement will further promote the large-scale use of all-solid-state lithium ion battery 18650 in China. As soon as this news came out, the topic of solid-state batteries was once again pushed to a "climax".

Under the current lithium-ion battery system, relying on the combination of high-nickel ternary positive electrode, silicon-carbon negative electrode and electrolyte, it will reach the limit of 350 watt-hours/kilogram in the next five years, and will still not meet the requirements of power batteries in terms of safety, energy density and cost.

Solid-state batteries have two very significant advantages. On the one hand, due to the use of traditional lithium ion battery 18650 with organic electrolytes, it is easy to cause the electrolyte to heat up under abnormal conditions such as overcharging and internal short circuits, thereby causing safety hazards such as spontaneous combustion or even explosion. Solid-state batteries are based on the conditions that solid materials are non-flammable, non-corrosive, non-volatile, and non-leaking, and the safety factor has an inherent advantage over lithium-ion batteries.

Secondly, solid-state batteries are expected to completely solve the mileage anxiety of pure electric vehicles in terms of the most critical energy density. The lithium-ion battery under the current system has reached its limit performance. Even the battery pack under Tesla's NCA18650 battery cell can reach an energy density of 250 Wh/kg. The energy density of the 21700 battery cell used in Model 3 reaches 300 Wh/kg, supporting a range of 400 to 500 kilometers, but it still cannot solve the range anxiety.

Under the existing technical route, if the ternary lithium battery wants to further improve the energy density, it can only continue to improve the nickel material or add CA. However, the thermal stability of high nickel is very poor. While increasing the capacity density, it also means that its stability decreases, the thermal reaction inside the battery will be more intense, and the safety hazards will become a bigger problem.

The electrolyte of the solid-state battery does not require a diaphragm and electrolyte, and there is no leakage, corrosion and other problems. It can simplify the battery shell and cooling system module, further reduce the weight of the battery module, and achieve energy saving. In addition, the new positive and negative electrode material matching can make the electrochemical window reach more than 5V, fundamentally improve the energy density, and is expected to reach 500 Wh/kg.

It is precisely based on the two issues of safety and energy density breakthrough that the current new energy vehicle industry authorities have also put forward higher requirements for the performance of power batteries. According to the relevant guidelines of the "Medium- and Long-Term Development Plan for the Automobile Industry" and the "Technical Roadmap for Energy-Saving and New Energy Vehicles", the energy density of the power battery system needs to reach 350 watt-hours/kilogram between 2025 and 2030 to meet the mileage requirements of passenger electric vehicles on the market.

From the current point of view, this goal is obviously impossible to achieve with only the technical research and development of lithium ion battery 18650. In order to ensure the high energy density and safety of power batteries, the research and development progress of solid-state batteries has brought hope to the entire new energy vehicle industry. Therefore, solid-state batteries are widely regarded as the correct technical research and development direction for the next generation of power batteries.

However, although solid-state batteries are good, according to the existing research and development progress, there are still two technical difficulties that have not been solved. One is that the ionic conductivity of solid electrolytes at room temperature is not high, and the other is that the interface impedance between solid electrolytes and positive and negative electrodes is relatively large.

At present, the solid electrolytes such as polymers, oxides, and sulfides used by major global automakers and battery manufacturers all have such problems. Specifically, polymers are not heat-resistant enough, have poor stability, and low ion conductivity. Oxides have strong resistance to price, but their ion conductivity cannot meet the requirements. Although sulfides have good conductivity, they lack ion transmission performance due to poor material stability.

It usually takes about ten years for a newly developed material to move from the laboratory to the market application level. Solid-state batteries are in the research and development stage, and it takes patience to achieve industrialization. Although it is widely believed that solid-state batteries have the advantages of high safety and high energy density, it is only a guess for forward research and development. Only when its mass-produced products show absolute advantages can they truly replace ternary lithium ion battery 18650.

For example, Tesla's ternary lithium battery technology is already very mature. Even if solid-state batteries are mass-produced in a short period of time, their performance can only reach the level of the former, and will not have a subversive significance. In other words, although everyone is optimistic about solid-state batteries, they still have a long way to go from the research and development stage to officially becoming the leading battery product. Therefore, traditional liquid electrolyte batteries still have at least several years of market space, and there is no need to worry about being eliminated soon.

Overall, solid-state batteries with high safety and high capacity density potential are bound to be the research and development direction of the next generation of power batteries, but there is indeed no mass-produced product that can obviously outperform traditional lithium-ion batteries in all aspects. We can only hope that solid-state battery technology will mature soon, and the range of electric vehicles will no longer be a commuter anxiety.

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