Electrochemical Lithium Recycling with Electricity Generation

Academic Background

With the global transition to a low-carbon society, the demand for lithium-ion batteries (LIBs) as an important energy storage technology is rapidly increasing. However, the limited availability of lithium resources and the disposal of spent batteries have become pressing issues. Traditional lithium recycling methods, such as pyrometallurgy, hydrometallurgy, and direct regeneration, while effective, are associated with high energy consumption, high chemical reagent usage, and environmental pollution. Therefore, developing an efficient, environmentally friendly, and economically viable lithium recycling technology has become a key focus of current research.

A research team from the University of Science and Technology of China (USTC) has proposed a novel electrochemical method that simultaneously recycles lithium from spent lithium-ion batteries and captures nitrogen dioxide (NO₂) from waste gas, while generating electricity and high-purity lithium nitrate (LiNO₃). This method not only addresses the challenge of lithium resource recycling but also provides a new solution for waste gas treatment.

Source of the Paper

This paper was authored by a research team from the Department of Applied Chemistry at USTC, with key contributors including Weiping Wang, Zaichun Liu, Zhengxin Zhu, and others. The paper was published in March 2025 in the journal Nature Sustainability, titled “Electrochemical lithium recycling from spent batteries with electricity generation.”

Research Process

1. Research Design and Experimental Methods

The research team designed an integrated system that combines lithium recycling with NO₂ capture. The system involves the following key steps:

• Preparation of Lithium Recycling Electrode: Spent lithium iron phosphate (LiFePO₄, LFP) electrodes were used as the lithium source, and carbon cloth served as the NO₂ reduction electrode.
• Electrochemical Reactions: In the electrochemical cell, the LFP electrode releases lithium ions (Li⁺) through delithiation, while NO₂ is reduced to nitrite (NO₂⁻) on the carbon cloth electrode.
• Product Formation: Li⁺ combines with NO₂⁻ to form lithium nitrite (LiNO₂), which is subsequently oxidized in air to high-purity LiNO₃.
• Electricity Generation: The system generates electricity throughout the process, achieving energy self-sufficiency.

2. Experimental Validation

The research team conducted a series of experiments to validate the feasibility and efficiency of the method:

• Energy Output Test: At a current density of 0.1 mA/cm², the system stably output 0.4 V of electricity, with a lithium recovery efficiency of 96.23%.
• Product Analysis: The formation of LiNO₃ was confirmed through X-ray diffraction (XRD) and scanning electron microscopy (SEM), while the presence of NO₂⁻ was verified using ultraviolet-visible spectroscopy (UV-Vis).
• System Stability Test: After eight consecutive uses, the lithium recovery efficiency remained around 97%, indicating high system stability.

3. Techno-Economic Analysis

The research team compared the energy consumption, carbon emissions, and economic benefits of this method with traditional lithium recycling methods. The results showed that this method significantly outperformed traditional methods in terms of energy consumption and carbon emissions, with a net profit of $2.41 per kilogram of LFP processed.

Key Results

• High Lithium Recovery Efficiency: At a current density of 0.1 mA/cm², the lithium recovery efficiency reached 96.23%, far exceeding that of traditional methods.
• High-Purity Products: The generated LiNO₃ had a purity of over 99%, making it directly usable in lithium-ion battery manufacturing.
• Energy Self-Sufficiency: The system generated electricity while recycling lithium, achieving energy recycling.
• Environmental Friendliness: The method does not require large amounts of chemical reagents and produces no harmful waste, significantly reducing environmental pollution.

Conclusions and Significance

This study proposes a novel electrochemical lithium recycling method that not only addresses the disposal of spent lithium-ion batteries but also provides a new solution for waste gas treatment. The method is efficient, environmentally friendly, and economically viable, offering new insights into the sustainable utilization of lithium resources and the development of a circular economy.

Research Highlights

• Innovation: The first integration of lithium recycling with NO₂ capture, achieving energy self-sufficiency.
• Efficiency: Lithium recovery efficiency of up to 97%, with high product purity.
• Environmental Benefits: No need for large amounts of chemical reagents and no generation of harmful waste.
• Economic Viability: A net profit of $2.41 per kilogram of LFP processed, demonstrating significant economic benefits.

Additional Valuable Information

The research team also explored the feasibility of this method in practical applications, including operational stability under different NO₂ concentrations, compatibility with other gases (such as CO₂ and SO₂), and the design of a continuous recycling system. These studies provide important references for further optimization of the method.

Through this research, the team from USTC has provided innovative solutions for the sustainable utilization of lithium resources and waste gas treatment, offering significant scientific and application value.