Hitachi develops 48V lithium-ion battery pack with 1.5 times higher energy density

It is reported that Hitachi Automotive Systems Co., Ltd. has developed a 48V lithium-ion battery pack with a new output density and energy density for medium-duty hybrid vehicles. The output density is 1.25 times that of the traditional single product, and the energy density is 1.5 times that of the traditional single product. In the future, Hitachi Automotive Systems will begin to supply samples to automaker customers and is committed to mass production in 2019.

In recent years, a medium-sized hybrid electric vehicle system driven by a battery and an electric motor-assisted gasoline engine has been widely concerned as a technology for effectively reducing the fuel consumption of passenger cars. In 2016, the annual production of global medium-duty hybrid vehicles reached approximately 450,000 units, and is expected to exceed 12.8 million units by 2023. Especially in Europe and China, the medium-oil hybrid system equipped with a 48V lithium-ion battery has a good fuel consumption reduction effect and a high cost performance, and will be rapidly popularized.

Hitachi Automotive Systems has been closely monitoring the market development trend. In March 2016, it developed a 48V lithium-ion battery pack for medium-duty hybrid vehicles, combining the lithium-ion battery bills used in hybrid vehicles. Body Manufacturing Technology and Battery Management System (BMS) technology.

Lithium-ion batteries are charged and discharged by moving lithium ions in the electrode material. In order to increase the battery output density, the conventional method is generally to reduce the thickness of the electrode film to reduce the electric resistance. However, after the output density is increased, there is a problem that the energy storage capacity is insufficient.

The new lithium-ion battery pack has improved the electrode structure of the battery in a micron order, forming a structure in which lithium ions are easy to flow, and reducing the resistance and increasing the output density without reducing the thickness of the electrode film.

At the same time, the material composition of the positive electrode and the negative electrode is further improved, the lithium content accumulated per unit weight is increased, and the energy density is improved. As a result, the new lithium-ion battery pack has a new high output density and energy density, the output density is 1.25 times that of the traditional single product, and the energy density is 1.5 times that of the traditional single product.

In addition, the new lithium-ion battery pack also controls the internal resistance of the battery cell, reduces the heat generation, and uses the metal with high thermal conductivity and heat dissipation to make the frame of the lithium-ion battery pack, eliminating the need for The cooling fan enhances the freedom of installation, effectively reducing the overall thickness of the product and enhancing the quiet performance.

As the output density increases, the torque performance of the motor acceleration assist is enhanced, and the maximum output power can reach more than 12 kW, and the starting force is more powerful. At the same time, the maximum input power has reached more than 15kW, and a large amount of renewable energy generated by the sudden braking can also be recovered, reducing energy consumption. On the basis of improved input and output performance, as the energy density increases, the fuel consumption is also effectively reduced.

In the future, Hitachi Automotive Systems will continue to provide electric power transmission products including high-performance, high-reliability lithium-ion batteries for electric vehicles with high market demand, and promote the development and popularization of electric vehicles to contribute to environmental protection. .