Bio-Derived Dimethyl Itaconate: A Sustainable, Low-Cost Electrolyte Additive for High-Performance Lithium Batteries

Abstract

The development of sustainable, cost-effective electrolyte additives is critical for advancing lithium-ion battery (LIB) technologies while addressing environmental concerns. Here, we present dimethyl itaconate (DMIC), a fully bio-based and industrially scalable additive derived from Aspergillus terreus-fermented itaconic acid, as a high-performance alternative to conventional vinylene carbonate (VC). The distinctive α,β-unsaturated ester structure of DMIC facilitates dual interfacial stabilization through preferential reduction at the anode (LUMO: -1.72 eV) and oxidation at the cathode (HOMO: -7.76 eV), forming robust solid/cathode electrolyte interphases (SEI/CEI) with gradient organic-inorganic compositions. The results show that, compared to VC-containing and Blank electrolytes, DMIC significantly enhances battery performance by reducing side reactions between solvent molecules and electrodes, improving Li+ transport kinetics at the electrolyte-electrode interface, and lowering internal resistance. This results in superior cycling stability, rate capability, and long-term performance. Specifically, the LiFePO4 (LFP)/Li battery with DMIC achieves a specific capacity of 103.1 mAh g-1 even at high current rates up to 4C. Cycling tests reveal that DMIC-containing electrolytes exhibit markedly improved capacity retention in both LFP/Li and LiNi0.6Co0.2Mn0.2O2 (NCM622)/Li cells. Furthermore, DMIC proves effective in LFP/graphite pouch cells, maintaining a capacity retention rate of 84.8% after 150 cycles at 0.5C. With a significantly lower production cost than VC and a synthesis process free of chlorinated intermediates, DMIC represents a paradigm for green, economically viable electrolyte engineering, aligning with global sustainability objectives for energy storage systems.