With the rapid expansion of end-use sectors such as portable electronic devices, new energy vehicles, and large-scale energy storage, the demand for lithium batteries with higher energy density, longer cycle life, and enhanced safety performance continues to rise. However, the irreversible loss of active lithium—a core pain point exposed during material iteration and performance upgrades—has constrained the industrialization process of high-specific-energy batteries. Lithium supplementation technology, as a targeted solution, has become a key enabling technology for breaking through performance bottlenecks and adapting to new electrode materials by actively compensating for active lithium loss.

Advantages and Disadvantages of Various Lithium Supplementation Technologies

1. Anode Pre-lithiation Technology: This involves lithiating the anode material before battery assembly by pre-embedding active lithium to compensate for subsequent losses. It is one of the earliest developed lithium supplementation routes, mainly including three sub-methods: lithium powder mixing, lithium foil lamination, and electrochemical pre-lithiation. The advantages include high lithium supplementation efficiency (capable of precisely compensating for 10%-20% of irreversible lithium loss). Among these methods, stabilized lithium metal powder (SLMP) offers controllable lithium supplementation, while electrochemical pre-lithiation provides high precision with no residual metallic lithium risk. The disadvantages are high environmental requirements for pre-lithiation—metallic lithium is highly reactive and requires an inert environment (moisture-proof and oxidation-proof) for operation. Additionally, excessive lithium supplementation can easily lead to lithium dendrite formation. Production requires dedicated pre-lithiation equipment with high investment, low efficiency, and increased industrialization costs.

2. Cathode Lithium Supplementation Technology: This involves adding lithium-rich compounds (lithium supplementation agents) during cathode preparation, which release active lithium during the first charge to compensate for losses. The advantages include extremely strong process compatibility—lithium supplementation agents (such as Li₂NiO₂, Li₂CO₃, LFO, etc.) can be directly added during the cathode slurry mixing stage without significant modification to existing production lines. It offers safe operation and relatively low cost, suitable for large-scale production, and is compatible with various cathode systems including lithium iron phosphate and ternary materials. Adding 3% LNO lithium supplementation agent can increase the energy density of lithium iron phosphate batteries by 4.9% and extend cycle life by more than 30%. The disadvantages include significant gas generation from lithium supplementation agents and longer formation process time, reducing production line output. Furthermore, cathode lithium supplementation efficiency is slightly lower than anode pre-lithiation, with limited compensation capability for high-capacity anodes.

3. Electrolyte Lithium Supplementation Technology: This involves incorporating lithium-containing compounds (such as lithium salts and organic lithium reagents) into the electrolyte to achieve active lithium replenishment through electrolyte transport during battery charge-discharge cycles. It represents an early form of "in-situ lithium supplementation." The advantages include uniform lithium supplementation that can proceed synchronously with the battery formation process, with simple operation. It can continuously replenish lithium losses during cycling to mitigate capacity decay, requires minimal modification to existing production lines, and offers broad compatibility. The disadvantages include limited lithium supplementation capacity, making it difficult to meet the demands of high-loss scenarios such as silicon-based anodes. Lithium-containing additives may affect electrolyte stability and trigger side reactions. Additive concentration control is challenging—excessive levels can lead to increased electrolyte viscosity, affecting ion transport efficiency.

4. In-situ Lithium Supplementation Technology: This breaks the traditional framework of "lithium source co-existing with the cathode" by injecting external lithium carrier molecules to replenish active lithium, enabling non-destructive restoration of batteries in service. It is represented by the lithium carrier molecule technology developed by the Fudan University team. The advantages include high precision in lithium supplementation, enabling targeted replenishment of lost lithium through "injection" methods to achieve non-destructive capacity restoration and significantly extend battery life. The disadvantages are that the technology is still in the early stages of industrialization, and the large-scale preparation process for lithium carrier molecules (such as CF₃SO₂Li) still requires optimization. Molecular reaction kinetics issues need to be resolved to avoid affecting battery formation speed. Minor modifications to battery packaging structure are required, and compatibility with existing older batteries needs further verification.

HSD's Achievements

Highstar actively explores cutting-edge industry technologies and has been involved in both cathode and anode lithium supplementation technologies, specifically:

Cathode Lithium Supplementation: By adding 2% lithium supplementation agent to the cathode and optimizing the formulation, product cycle life has been improved by 30%. Calculated at 70% retention rate, room temperature cycling reaches over 8,000 cycles; high-temperature cycling at 45°C achieves over 3,500 cycles; 28-day charge retention recovery rate is more than 1% higher than conventional batteries, reaching 98%; at 0.5-3C rate performance, it is more than 1% higher than conventional batteries.

Anode Lithium Supplementation: Through anode lithium supplementation, cycle life has improved by 100% compared to conventional batteries. Calculated at 70% retention rate, room temperature cycling reaches over 12,000 cycles; high-temperature cycling at 45°C achieves over 6,000 cycles; 28-day charge retention recovery rate is about 2% higher than conventional batteries, exceeding 99%; at 0.5-3C rate performance, it is more than 1% higher than conventional batteries, with temperature rise reduced by 2-3°C.

Highstar's research on lithium-supplemented batteries has achieved industry-leading cycle life standards. Lithium-supplemented batteries possess longer service life, and their charge storage level ensures tolerance for long-distance, high-temperature transportation. Their excellent rate performance can also meet usage scenarios sensitive to temperature rise.