Opportunities and challenges of lithium-ion batteries

Opportunities and challenges of lithium-ion batteries   

Lithium-ion batteries can be roughly divided into three main areas from the application scenario:3C electronic products (computer, communication and consumer electronics), electric vehicles and static energy storage of scale. Due to the different application scenarios, the requirements for comprehensive performance indicators of lithium-ion batteries are also vary greatly, so the maturity and market share of lithium-ion batteries in different application areas are different at present. Overall, lithium-ion batteries occupy almost all the market in the field of 3C electronic products. In the area of electric vehicle transportation, lithium-ion batteries dominate the power battery market, and are now dominant in the field of electric vehicle applications. In the future, as the cost of lithium-ion batteries continues to decrease and the performance of lithium-ion batteries continues to improve, the performance-price ratio of electric vehicles is expected to increase and surpass fuel-fueled cars in 2024. In addition, in recent years, electric vehicles are no longer limited to new energy electric vehicles with relatively small total system energy requirement(1-100KWh), and began to expand the system energy to electric ships and electric rail transit above MWh level. Although currently electric ships and electric rail transit have no advantages in economy, they have prominent advantages in energy saving, emission reduction, green environmental protection, so they start to have commercial demonstrations in some special areas and regions. On November 12, 2018, the world's first 2000-ton new energy pure electric ship, built by Guangzhou Ship International, was hoisted and launched at Guangzhou. Its captain was 70.5 m, and it was equipped with a super capacity of 26 t plus ultra-high power lithium batteries. The capacity of the whole ship's batteries was about 2.4 MWh. Under full load conditions, the ship's speed could reach 12.8 km/h and its endurance could reach 80 km.In recent years, there have been initial attempts in the field of electric aircraft. However, due to the high self-importance of aircraft, the current lithium-ion battery energy density is far from meeting the requirements of commercial airliners. A full-electric DHC-2 (DHC-2 de Havilland Beaver) seaplane from Harbour Airlines Australia conducted a test flight in December 2019. Although limited by power battery energy density and self-weight, the flight lasted less than 15 minutes, it was the first test flight of a full-electric commercial civil aviation aircraft. Preliminary estimates suggest that the weight and energy density of power batteries will need to be at least doubled (> 600 Wh/kg) from the current level in order to electrify a 1000 km standalone passenger aircraft in the future. Therefore, the full electronization of vehicles will undoubtedly be a huge opportunity for lithium-ion batteries in the future, and it will also be a huge challenge for lithium-ion batteries. How to maintain other performance on the existing basis while achieving a significant increase in energy density will be the key factor determining the development of lithium-ion batteries in the power battery field in the future.

Lithium-ion batteries have great potential for large-scale energy storage in the future, in addition to their promising applications in electric vehicles.With the continuous deepening of China's energy transformation, it is expected to achieve the goals of safe and controllable energy supply, clean energy production, low carbon and energy consumption, high efficiency and environmental protection.China will continuously increase the proportion of non-fossil renewable energy in the total primary energy of our country. By 2035, it is expected that the renewable energy will exceed 35% of the primary energy weight of our country. The wind and solar energy which are the main relying sources of renewable energy are intermittent energy, and a high proportion of energy storage devices are needed to use with it. In the future, lithium-ion batteries will play a key role in large-scale energy storage, especially in promoting renewable energy consumption and distributed energy storage. They will also play an important role in regulating power grid frequency and peak regulation, gradually reducing China's dependence on thermal power generation. 

In addition, lithium-ion battery energy storage technology can achieve a better balance between supply and demand on the user side. It is expected that a 100 GWh Li-ion battery market will be developed in the next 15 years in the field of large-scale energy storage. By then, with the help of advanced 5G technology, artificial intelligence, large data and block chain technology, China will initially form an advanced smart grid. Electric vehicles will gradually change from the existing disordered charging to ordered charging and then to smart charging V2G, thus realizing a new energy supply mode of efficient interaction and complementary between electric vehicles and large-scale storage. However, to achieve this good situation, the precondition is to develop a lithium-ion battery system with sufficient technical economy, long life and safety. Considering the future V2G technology for vehicle-network interaction in power batteries, lithium-ion power batteries need to continue to improve their cycle life. At present, the cycle life of power batteries is generally around 1000 weeks. In the next few weeks or so, if you use electric vehicles as mobile energy storage devices, the cycle life will need to be increased to more than 3000 times, which is a major technical challenge for high energy density lithium-ion batteries. In addition, in terms of large-scale static energy storage, lithium-ion batteries not only need to meet the requirements of high safety, but also need to have a higher cost-effectiveness than existing pumped storage technology. Therefore, how to develop the next generation of safe, high energy density and long-life power batteries and safe, efficient, low-cost, large-scale and long-life energy storage batteries will be the key to the success of lithium-ion batteries in the related power batteries and energy storage market.

Due to the use of flammable organic substances as liquid electrolytes in commercial lithium-ion batteries, there are significant safety hazards and fire and explosion in the case of battery abuse and thermal uncontrollability caused by accidents.The destructive power increases significantly with the increase of system energy.How to develop intrinsically safe lithium-ion batteries in the future will be another decisive factor to determine the development of lithium-ion batteries. From the current global research and development direction, using solid electrolyte instead of organic flammable liquid electrolyte is a mainstream trend in the future development of lithium-ion batteries. However, how to solve a series of scientific and technical problems caused by solid-state replacement of liquid electrolyte. It will still take a long time.

 Prospect

The Nobel Prize is recognized as the highest laurel of the Human Science Prize. The award of a Nobel Prize for scientific discovery or technological invention is often regarded as a highly recognized contribution to the development of human society by the whole society. In this sense, the Nobel Prize for Chemistry 2019 for lithium-ion batteries should be expected. However, the number of Nobel Prize winners is strictly limited to three, which also makes it impossible for many scientists who have made great contributions to the development of lithium-ion batteries to be included, especially lithium-ion batteries, which are scientific technologies and products with high application value. Their success step by step depends on the great efforts and contributions of many scientists and engineers. Therefore, while warmly congratulating the three winners, we should not forget that other well-known scientists and engineers who have made outstanding contributions in the history of lithium-ion batteries. The Nobel Prize for Chemistry in 2019 is the highest affirmation of the Lithium-Ion Battery technology that has profoundly impacted the changes of human society in the past, but also a higher expectation for the future Lithium-Ion Battery technology.It is believed that in the future, with the continuous progress of lithium-ion battery technology, lithium-ion batteries will be widely used in more fields, and their future will be more brilliant.