The lithium battery-grade water-based lithium-acid cellulose binder project supported by the 2019 project support of the Natural Science Foundation of Chongqing Municipal Science and Technology Commission, the 2019 project support of the Youth Fund of Chongqing Municipal Education Commission and other special fund projects, and successfully carried out the transformation of scientific and technological achievements in 2021, and realized the industrialization development of combining production, education and research, A research article“High Performance Study of Lithium Carboxymethylcellulose as Water-Soluble Binder for Lithium Supplementation in Lithium Batteries“ was published in the cellulose industry SCI journal “Starch – Stärke” in March 2022 by the team of Qiu Lei, the founder of Green Energy Fiber Materials.

In the research, carboxymethyl cellulose lithium (CMC-Li) was synthesized and obtained using cotton and lithium ethoxide as raw materials, and it is used as a water-based binder in the negative electrode of lithium batteries, the relevant electrochemical performance was also tested. Studies shown that CMC-Li has better electrochemical performance as a lithium supplementation binder for lithium batteries, which can reduce the internal resistance of the battery by about 10%, significantly improve the lithium evolution phenomenon, reduce the redox peak by 50% to 0.20V, and significantly improve the impedance, reducing it by more than 50%. Under the same conditions, 2500 cycles is reachable, the life is increased by more than 20% Compared with CMC-Na. The obvious  lithium replenishment effect further verifies the electrochemical performance advantages of the lithium supplement binder.

                                                                                                                                                      Infrared spectroscopic characterization

                                                                                                                                                                                    of cellulose powder and CMC-Li

Study on Internal resistance of lithium batteries using CMC-Na and CMC-Li as bonding materials (left) and comparison of lithium analysis (right)

CV test (left) and cycle life comparison (right) of battery materials using CMC-Na(A/B) and CMC-Li(C/D) as binders

In addition, Qiu Lei et al from Chongqing University of Technology published a paper in April 2023. The team successfully synthesized lithium carboxymethyl cellulose (CMC-Li) by slurry method using cellulose powder and lithium ethanol as raw materials, and compared it with sodium carboxymethyl cellulose (CMC-Na) as the negative electrode binder for lithium ion batteries. It shows excellent suspension and dispersion properties in LFP system.

Moreover, under the same conditions, CMC-Li can improve the compaction density, liquid absorption rate and liquid absorption volume of the electrode, reduce polarization phenomenon, reduce internal resistance by about 10%, reduce physical rebound by about 14.5%, increase the specific capacity of charge and discharge by about 1%, increase the peel strength by about 9.8%, increase the first effect by about 2%, and extend the cycle life by about 12%. The results show that the lithium filling effect is obvious and the binder performance is excellent.

Infrared spectra of cellulose powder, CMC-H, CMC-Li

Comparison of sedimentation and dispersion properties of different cellulose binders (left) and pole strip peel strength (right)

Test curves for imbibition and compaction density (left) and physical rebound (right) of CMC-Na and CMC-Li as binders

Impedance polarization performance test of different

Comparative study on cycle performance of cellulose binder assembled battery

(LFP system) at different temperatures