From the current mass-produced lithium-ion power battery products of various companies, the existing lithium-ion power batteries can be divided into two categories:
One type is to use small standard cylindrical batteries (represented by 18650 batteries, other types such as 26650, 20700, 32650 and 32700, etc.) to assemble power battery systems. Generally, multiple series and parallel connections are required to meet the total voltage and total capacity requirements, the number of single batteries reaches thousands, and the connection is complicated;
The other type uses a large-capacity power battery, the maximum capacity can reach tens of ampere hours or even higher, using aluminum-plastic film packaging or metal shell welding packaging. Due to the large capacity of single batteries, the number of single batteries combined into a module and system is greatly reduced, and the connection is relatively simple.
Japan Vehicle Energy Supply Company (AESC) mainly produces supporting power batteries for Nissan’s Leaf electric vehicles. The mass-produced energy-type single battery has a capacity of 33.1A·h, the specific energy of the single battery has reached 157W·h/kg, and the specific energy of the battery system has reached 82W·h/kg, and more than 185,000 Leaf electric vehicles have been installed. South Korea’s LG Chem mass-produced 15A·h energy-power balanced single battery (actual capacity reached 15.9A·h) with a specific energy of 155W·h/kg; the specific energy of the 26A·h and 29A·h energy-power balanced single cells reached 170W·h/kg and 161W·h/kg (mass production in 2015), which are matched by GM Volanda’s extended-range hybrid electric vehicle; the mass-produced 41A·h energy cell has a specific energy of 158W·h/kg, and the 36A·h and 37A·h energy cell has a specific energy of 157W·h/kg. Japan’s Sanyo Electric has produced 21.5A·h single batteries for Toyota Prius plug-in hybrid vehicles, with a specific energy of 110W·h/kg. The 3.1A·h 18650 cylindrical lithium-ion battery supplied by Panasonic Corporation of Japan for the mass production of Tesla Motors in the United States. The specific energy of the single cell reaches 233W·h/kg, and the specific energy of the battery system reaches 127W·h/kg. At present, Panasonic has increased the battery capacity to 3.4A·h. South Korea’s Samsung SDI is supporting the mass production of lithium-ion power batteries for pure electric vehicles of companies such as Fiat. The capacity of the single battery is 64A·h, and the specific energy of the single battery is 132W·h/kg. In 2016, 94A·h power battery products will be launched, with a specific energy of 160W·h/kg; 3.1A·h 18650 cylindrical batteries for electric vehicles, with a specific energy of 245w·h/kg. At the same time, in 2015, it launched 3.3A·h 18650 cylindrical batteries for electric vehicles; for plug-in hybrid vehicles, launched 28A·h lithium-ion power batteries, and in 2016 launched second-generation power battery products with higher capacity. The 20A·h lithium titanate battery introduced by Toshiba has the ability of 8C fast charging, can be charged to 80% capacity in 6 minutes, the energy density reaches 89W·h/kg, the charging power density reaches 2400W/kg, the discharge power density reaches 2200W·h/kg, and the cycle life exceeds 6000 times. The 50A·h lithium-ion power battery produced by the Japanese Lithium Energy Company has a specific energy of 109W·h/kg. The lithium-ion power battery produced by South Korea’s SKI company has a specific energy of 200W·h/kg.
In terms of key materials, the development trend of vertical integration in the industry chain of key materials (or batteries) enterprises is obvious. For example, LG Chem began to get involved in the fields of cathode materials, separators, and electrolytes, and BASF began to get involved in cathode materials and electrolytes, and international giants accelerated the process of industrial technological innovation and industrialization faster with the concept of vertical ecological development.
Generally speaking, from the perspective of application in the field of pure electric drive vehicles, the energy density of the large-capacity power battery products (capacity greater than 10A·h) that power battery companies produce in mass production is mostly between 110-160W·h/kg, and some products Can reach 200W·h/kg; small-capacity power battery products are typically 18650 cylindrical batteries (capacity of 3.1A·h and 3.4A·h, etc.), and the energy density can reach 230~250W·h/kg. Fast-charging lithium-ion power batteries are represented by lithium titanate batteries (capacity 20A·h), with an energy density of 89W·h/kg.