Researchers at Fraunhofer IKTS and Friedrich-Schiller-University Jena – both part of the Center for Energy and Environmental Chemistry Jena (CEEC) – are developing a sodium-ion battery system based on lignin, a by-product of the wood and pulp industry.
Typically incinerated for energy, lignin is a biopolymer that gives wood its structural integrity.
The ThüNaBsE project (Thuringia Sodium-Ion Battery for Scalable Energy Storage), funded by the Free State of Thuringia and the European Social Fund, is advancing this concept from raw material to a 1-Ah full cell. The initiative aims to reduce reliance on critical raw materials and promote safer, more sustainable battery technologies. An industrial advisory board – featuring Mercer Rosenthal, Glatt Ingenieurtechnik, IBU-tec advanced materials, EAS Batteries and Petrochemical Holding – supports the work.
Lignin is thermally converted into hard carbon under inert conditions. “The structure of this hard carbon is very suitable for the reversible storage of sodium ions. Hard carbon boasts high electrochemical performance, good cycle stability and low acquisition costs, especially if obtained from sustainable raw materials”, explained Cornelius Dirksen.
Prussian Blue analogs will serve as the positive electrode material.
“After 100 charging and discharging cycles, the lab cell shows no significant degradation,” said Lukas Medenbach, research scientist at Fraunhofer IKTS. “The aim is to demonstrate 200 charging and discharging cycles for the 1-Ah full cell by the end of the project.”
Applications could include microcars and warehouse vehicles. The team plans to scale the technology further with a larger consortium.
