From theoretical energy density calculation to real energy density performance: lithium loss and capacity degradation
For lithium-ion batteries, the positive and negative electrodes have high specific capacity and high potential difference. At the same time, sufficient active lithium needs to “shuttle” between the positive and negative electrodes as carriers to reflect high energy density and cycle life. The active lithium introduced by the electrode will not play an active role because of the formation of solid electrolyte membrane (SEI) on the surface of the negative electrode.
Pre lithium, clear-cut route selection
Pre lithium refers to the introduction of substances with high lithium content into the battery material system (mainly on the positive / negative side) and the effective release of lithium ions and electrons, so as to make up for the loss of active lithium and improve the actual energy density and cycle life of the battery. Different pre lithium technologies have obvious “long board” and “short board”. Where safety and process compatibility are more emphasized and the demand for lithium supplement capacity is not high, lithium supplement with positive electrode is usually more appropriate. When large capacity lithium supplement is required, lithium supplement of negative electrode is usually more appropriate.
Pre lithium patent layout: mainly in China, involving all links of lithium supplement
There are more than 1000 patents in effective, substantive examination and public status. They are searched in Chinese and English keywords, and the main number of applications is in China. The main applicants are battery enterprises. In addition, many scientific research institutes and some material enterprises also have layout.
Relatively speaking, the cathode lithium replenishing agents and application methods based on various lithium rich metal salts (and various modification and optimization methods) have a high maturity; Lithium metal based negative electrode lithium replenishing agent competes with lithium metal / neutral lithium compound and silicon oxide high temperature reaction for negative electrode side lithium replenishment. We expect that the pre lithium technology will be able to enhance the competitiveness of batteries with high energy density / long life demand.
Estimation of lithium supplement scale: market space or 10 billion yuan level in 2025
Pre lithium technology is attractive to power lithium batteries with high energy density (especially characterized by high nickel ternary cathode silicon carbon cathode) and energy storage lithium batteries with high cycle life (characterized by lithium iron phosphate cathode). We estimate that by 2025, the power battery equipped with high nickel ternary silicon carbon negative electrode will have about 100000 tons of silicon carbon negative electrode. Assuming that this part of negative electrode materials need to be doped with pre lithium silicon based materials by 10%, the corresponding demand for pre lithium silicon based materials is about 10000 tons, and the market space may be in the level of billions of yuan; Lithium iron phosphate energy storage battery corresponds to about Shanghai Pudong Development Bank Co.Ltd(600000) tons of lithium iron phosphate cathode. Assuming that this part of cathode materials need to be doped with positive composite lithium oxide lithium supplement agent by 5%, the corresponding demand for lithium supplement agent is about 30000 tons, and the market space may reach the level of 10 billion yuan Shenzhen Dynanonic Co.Ltd(300769) , Yanyi new materials and other enterprises took the lead in the large-scale development of lithium supplement.
Investment evaluation and suggestions
Investors are advised to pay attention to the listed companies that have laid out the pre lithium technology patents and carried out the production layout of pre lithium materials; Focus on listed companies of lithium resources; In view of the strong correlation between silicon-based anode and pre lithium technology, it is also recommended to pay attention to listed companies with silicon-based anode business.
Risk analysis
The progress of pre lithium technology is less than expected; The cost competitiveness of lithium supplement agent and lithium supplement process is less than expected, and the comprehensive optimization degree of battery performance is less than expected.
