Diluents Effect on Inhibiting Dissolution of Organic Electrode for Highly Reversible Li-Ion Batteries

HW Lee and Y Kim and JE Kim and JY Kim and JY Jang and J Choi and WJ Kwak, ADVANCED ENERGY MATERIALS (2023).

DOI: 10.1002/aenm.202303033

The potential of organic electrodes in lithium-ion batteries (LIBs) is highlighted by their cost-effectiveness and natural abundance. However, the dissolution of the active material in the electrolyte is a major obstacle to their use in LIBs. Although high-concentration electrolytes (HCEs) have been proposed to address this issue, they face challenges such as high viscosity, poor wettability, and suboptimal ion conductivity. Hence, this study introduces diluted electrolytes as non- solvating electrolytes to offset the physical limitations of HCEs and suppress the dissolution of organic electrodes. When a diluted electrolyte is used, perylene-3,4,9,10-tetracarboxylic dianhydride (PTCDA)-a notable organic electrode material-demonstrates superior capacity retention and rate performance, achieving 91% of capacity retained at 1000 mA g-1 over 1000 cycles. Through electrochemical and spectroscopic measurements and molecular dynamics simulations, the diluted electrolyte successfully inhibits and demonstrates the dissolution of the active material, preventing capacity loss and the detrimental shuttle effect. This study presents a promising strategy for achieving highly reversible organic electrode-based LIBs through the development of nonsolvating electrolytes. The dissolution of the organic electrode is detrimental to long-term cyclability. Localized high- concentration electrolyte (LHCE) is introduced as a promising approach to suppress the dissolution. Diluent in LHCE modulates the interface of PTCDA via the physical and chemical properties that diluent has contributing to the suppressed dissolution. As a consequence, the organic electrode with LHCE exhibited superior cycling performance.image

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