What are the mature technologies for lithium-ion batteries?

1. Full solid LiFe2+
Liquid lithium-ion batteries are currently used on the market, so they are also called liquid lithium-ion batteries. In short, it is an all-solid-state lithium-ion battery. All its components are solid, and solid electrolytes replace the liquid electrolytes and separators of traditional lithium-ion batteries.
Compared with liquid lithium-ion batteries, all-solid electrolytes have the following advantages: It has very good safety and heat resistance, and can work for a long time in the range of 60-120°C. Wide electrochemical window, up to 5 V, can be matched with high-voltage materials; only lithium ions, no electrons; has a simple refrigeration system and high refrigeration density; suitable for ultra-thin and flexible batteries. But its shortcomings are also obvious, that is, the battery has low conductivity per unit area, low specific power at room temperature, and high cost. Large-capacity batteries are difficult to industrialize.
The power density, cycle stability, safety performance, high and low temperature performance and service life of all-solid-state lithium-ion batteries are closely related to the performance of the electrolyte material. Solid electrolytes can be divided into polymer electrolytes (usually composed of PEO, LiTFSI, etc.) and inorganic electrolytes (such as oxides and sulfides). All-solid-state battery technology is considered to be the key to the next development. As the technology continues to mature, all problems will be solved.

2. Ternary material high energy density battery
With the development of high-energy-density lithium-ion battery technology, ternary cathode materials have attracted widespread attention. Ternary cathode materials are widely used in the field of energy storage due to their high specific capacity, good cycle stability and low cost. The energy density of the ternary cathode material can be effectively increased by increasing the voltage of the battery and the content of nickel element in the material.
Theoretically, ternary materials have natural advantages in high voltage: the standard value of ternary cathode materials is 4.35 V. At this value, ternary materials can also maintain good cycle stability. When the charging voltage increases to 4.5 V, the capacity of the (333, 442) symmetrical material can reach 190, and the cycle performance is also good, while the cycle performance of (532) is slightly worse; when the voltage reaches 4.6 V, the ternary material has Cycle performance begins to degrade and swelling becomes more severe. At present, the practical application of ternary high-voltage cathode materials is limited by the high-voltage electrolyte.
By increasing the Ni content to increase the energy density of the ternary system, high Ni ternary systems are currently commonly used, that is, high Ni ternary systems with Ni mole fraction >0.6. This system has the advantages of high specific capacity and low cost, but has storage problems. Lithium has problems such as weak capability and poor thermal stability. Therefore, modifying it is an effective way to improve its performance. Micro-nano size and morphology are important factors that determine the performance of high-Ni ternary cathodes. Existing research mainly obtains spherical particles of small size and high specific surface area through uniform dispersion on the electrode surface.