Functional Biopolymer Binders for High-Energy-Density and Ultrafast Cycling Lithium-Ion Batteries Operating at Extreme Temperatures (BLISET)
Final Report Abstract
Almost thirty years after their successful market launch, rechargeable Li-ion batteries with high energy density and a long cycling life are experiencing ever-increasing demand. In addition, safety, sustainability, cost efficiency, high current load and operation in a wide temperature range are very important aspects for batteries. Batteries are expected to deliver excellent performance worldwide, regardless of geographical location and associated climate. To achieve such goals, attention is focused not only on optimizing the electrode material, but also on other battery components. One of the key components of batteries is the binder, which is responsible for the homogeneous distribution and cohesion of the particles (electrode material and conductive carbon) that compose the electrodes. The binder also ensures strong and lasting adhesion to the current collector and also contributes to faster diffusion of the lithium ions. The aim of this project was to develop a more environmentally friendly process for producing electrodes with improved mechanical, thermal and conductive properties using the binder to increase battery performance at high current rates and to expand the temperature range for Li-ion battery operation. To achieve these goals, a new type of binder based on the biopolymer chitosan was prepared. In addition to chitosan this new binder also contains an ionic liquid PYR14DCA and a lithium salt LiTFSI. In the project, this polymer gel binder (PGB) was introduced in high-performance Li-batteries on both the cathode and anode side and examined at different current rates and operating temperatures. It was found that the binder in combination with a conventional LiFePO4 cathode at 60 °C greatly reduces Fe-dissolution in the electrolyte and the subsequent Fe-diffusion to the anode, thus enhancing the battery performance significantly in contrast to the conventional LiFePO4/PVDF electrodes with PVDF binder. In combination with a graphite anode, the new PGB binder also showed increased performance compared to the graphite/PVDF anode, reflecting supported high Li+ diffusion and the LiF-enriched interlayer (solid-electrolyte-interface, SEI) between the graphite/PGB electrode, which reduces charge transfer through the SEI. During the course of the project, other biopolymers such as gelatin, pectin and DNA were also investigated as one-component binders, the advantages of which are based on a very simple and environmentally friendly preparation method. They showed promising potential for application in Li-ion batteries for low-temperature operation below 25 °C.
Publications
-
Dissertation zur Erlangung des wissenschaftlichen Grades Doktoringenieur mit dem Titel „Novel Polymer Gel Binder for Li-ion Batteries with Improved Electrochemical Performance“, TU Dresden, Januar 2022.
Ling Ding
-
Superior high-temperature rate performance of LiFePO4 cathode: The stabilizing effect of a multicomponent gel biopolymer binder. Journal of Power Sources, 521, 230955.
Ding, Ling; Leones, Rita; Schmeida, Toni; Nielsch, Kornelius & Mikhailova, Daria
-
Graphite Anode Functionalized with a Gel Biopolymer Binder for Li-Ion Batteries Operating in a Broad Temperature Range. ACS Applied Energy Materials, 6(8), 4404-4412.
Ding, Ling; Bagul, Pratik; Cui, Liyao; Oswald, Steffen; Pohle, Björn; Leones, Rita & Mikhailova, Daria
