Reviving Lithium Batteries: Fudan University’s Breakthrough with "Lithium Battery Injection" Technology

In a groundbreaking innovation, a team of researchers led by Professor Peng Huisheng and Researcher Gao Yue from the Department of Polymer Science at Fudan University has developed a new technology that aims to "revive" lithium-ion batteries. Dubbed "lithium battery injection," this technique is set to revolutionize the longevity of batteries and significantly address the challenges faced by electric vehicle (EV) battery life.

Background: The Limitations of Lithium-Ion Batteries

Since the commercialization of lithium-ion batteries in 1990, they have been a cornerstone of energy storage in various applications, particularly in consumer electronics and electric vehicles. However, these batteries have been plagued by a fundamental contradiction. The lithium ions stored in the cathode material act as both the energy carrier and the "sand in the hourglass" for the battery’s lifespan.

As batteries undergo repeated charging and discharging cycles, lithium ions are gradually lost due to side reactions, resulting in “lithium depletion” even if the electrode materials remain intact. This degradation process leads to the battery’s failure over time, typically after 6 to 8 years in electric vehicles. This limitation has contributed to a significant amount of e-waste and a short service life for EV batteries, presenting a major challenge to the green energy transition.

The Core Technology and Mechanism: The Lithium "Lifeline"

At the heart of this technology is a compound known as lithium trifluoromethanesulfonate (CF₃SO₂Li), which acts as a "lifeline" for lithium-ion batteries. This compound serves as a rejuvenating agent, capable of "reviving" the battery’s performance. The key properties of this compound include:

• Reversibility: CF₃SO₂Li can be irreversibly oxidized within the 2.8–4.3V charging voltage window, releasing lithium ions. These ions then participate in the charging and discharging cycles of the battery, effectively replenishing the battery's lithium content.

• Zero Residue: The oxidation process releases sulfur dioxide (SO₂), trifluoromethyl (CHF₃), and other gases, which are expelled via the battery's ventilation system, ensuring "zero residue" in the battery.

• Compatibility: This compound is soluble in standard electrolytes, and it is compatible with common materials like graphite, silicon-carbon anodes, and various cathode materials.

• Cost-Effectiveness: The synthesis cost of CF₃SO₂Li is low, making it an affordable addition to lithium-ion batteries. Its cost as an additive is less than 10% of the total battery cost, making it economically feasible for large-scale adoption.

"Injection" Process: Recharging the Battery

The process of "injecting" lithium into the battery involves several steps that ensure the longevity of the battery:

1. Preparation: The CF₃SO₂Li compound is dissolved in the electrolyte to a concentration of up to 12.5%.

2. Injection: The mixed solution is injected into the battery through a reserved conduit, targeting non-activated "dry" cells.

3. Activation: During charging, the lithium salt breaks down at the anode, releasing lithium ions that are then embedded in the battery’s anode material.

4. Purification: The decomposition gases are expelled through a specialized sealing process, ensuring no harmful residues remain, thus allowing the battery to be returned to service.

Technological Benefits: Extended Battery Life and Reduced Environmental Impact

This new technology is set to revolutionize the lifespan and efficiency of lithium-ion batteries:

• Significant Lifespan Increase: The technology has been shown to extend the cycle life of commercial lithium-ion batteries by an impressive factor of 1-2 orders of magnitude. While typical lithium-ion batteries last between 500 and 2000 cycles, this technology can increase their lifespan to over 12,000 to 60,000 cycles, with a capacity retention of 96%.

• Environmental Benefits: For each battery revived using this technology, it is estimated that around 5 kg of heavy metal pollution and 10 kg of carbon emissions can be prevented. This could significantly reduce the need for battery disposal and recycling, thus contributing to a cleaner and more sustainable environment.

Future Prospects: Commercial Potential and Applications

The team is currently working on scaling up the production of the lithium carrier molecule and is collaborating with top international battery manufacturers to bring this technology to market. The process is expected to cost less than 10% of the total battery cost, making it an affordable solution for the electric vehicle industry and energy storage applications.

This breakthrough has the potential to be applied in a variety of areas:

• Lithium Replenishment: The technology can be used to replenish lithium in EV batteries, extending the useful life of existing batteries and making EVs more sustainable.

• Energy Storage: The technology can be applied to grid-scale energy storage systems, improving the efficiency and lifespan of energy storage solutions.

• Solar + Storage Integration: With its long lifecycle and environmental benefits, the technology could be integrated into solar power systems, helping to optimize energy storage in solar installations.

Conclusion

Fudan University’s lithium battery "injection" technology represents a paradigm shift in the way we think about battery longevity and sustainability. By addressing the fundamental issues that lead to battery failure, this innovation holds great promise for the future of electric vehicles, renewable energy, and beyond. With its low cost, environmentally friendly approach, and scalability, this technology could play a key role in reducing electronic waste and contributing to a more sustainable world.