Recently, Assistant Professor Lei Tian, Professor Caizhen Zhu and Professor Jian Xu’s team from the College of Chemistry and Environmental Engineering at Shenzhen University published the latest research progresses about high-performance solid-state lithium metal batteries on journal《Advanced Functional Materials》.

At present, the use of solid or quasi-solid state batteries instead of liquid batteries is an effective way to solve the safety problems of large new energy devices such as electric vehicles, but there are still many defects, which seriously hinder its further practical applications, such as low mechanical strength, low ionic conductivity, and interface contact problems between electrodes. Cellulose-based solid electrolyte, as a typical representative, has the characteristics of low cost, high strength and sustainability, it contains rich polar groups, such as ether bonds, can conduct lithium ions, and become a potential polymer matrix for composite fast ion conductors (such as LATP), which has great application potential in the field of solid lithium metal batteries. However, due to the interaction of a large number of hydrogen bonds between cellulose molecules, cellulose molecules are tightly arranged, resulting in a decline in the transport capacity of lithium ions, which seriously limits its further development. In view of the above problems, this paper proposes an ion conductive molecule grafting strategy, which further opens the ion transfer channel between cellulose, improves the ion conduction ability of electrolyte and improves the interface performance between electrolyte and positive and negative electrode in lithium battery. CLA-CN-LATP quasi-solid composite electrolyte with high ionic conductivity and excellent room temperature capacity retention was prepared.

The CLA-CN-LATP quasi-solid composite electrolyte (QCE) prepared by the grafting strategy of ionic conducting molecules proposed in this work has excellent ionic conductivity of 1.25×10^-3 S cm^-1 at room temperature. The assembled Li |CLA-CN-LATP|Li symmetric battery is capable of achieving highly stable lithium deposition/stripping for over 1200 hours at 0.1mA cm^-2 current density. In addition, the assembled LFP |CLA-CN-LATP QCE| Li has good cyclic stability at 0.5C and 25℃, and the capacity retention rate is as high as 92.1% after 1500 cycles. This work provides an effective strategy for further opening the ion transport channels between cellulose chains and improving the interface properties between electrolytes and electrodes.

The research article "Ion-Conducting Molecular-grafted Sustainable Cellulose Quasi-Solid Composite Electrolyte for High Stability Solid-state Lithium-Metal Batteries" is published in 《Ion-Conducting Molecular-grafted Sustainable Cellulose Quasi-Solid Composite Electrolyte for High Stability Solid-state Lithium-Metal Batteries》，authored by Master's student Ruixue Wang is the first author of this paper. Associate Professor Lei Tian is the corresponding authors of this paper. The corresponding unit is the School of Chemical and Environmental Engineering, Shenzhen University.

The authors are grateful for the support from the National Natural Science Foundation of China, Shenzhen Science and Technology Major Project and Shenzhen Science and Technology Program, the Program for Guangdong Introducing Innovative and Entrepreneurial Teams, Guangdong Basic and Applied Basic Research Foundation, and sponsored by CNPC Innovation Fund.

Article details:

Ruixue Wang, Weiliang Dong, Zhennuo Song, Jiji Tan, Qiang Liu, Kexin Mu, Weijian Xu, Haiyu Huang, Zhili Zhang, Gang Yin, Caizhen Zhu, Jian Xu, and Lei Tian*, Ion-Conducting Molecular-Grafted Sustainable Cellulose Quasi-Solid Composite Electrolyte for High Stability Solid-State Lithium-Metal Batteries.Adv. Funct. Mater.2024, 2402461.

https://doi.org/10.1002/adfm.202402461