Kinetic regulation of blended electrolytes enables long‐term state retention in organic artificial synapses

Artificial synapses based on organic electrochemical transistors (OECTs) are promising candidates for neuromorphic computing, yet their performance is critically limited by non‐volatile state retention. Although polyelectrolytes offer a new approach, existing options fail due to extremely low ion migration rates. This limitation arises largely from the intrinsic kinetics of ion transport within the electrolyte. Here, a kinetic regulation strategy is demonstrated using a blended electrolyte composed of a poly(ionic liquid) (PIL) and an ionic liquid (IL). The high glass transition temperature ( T g ) of the PIL restricts segmental motion, creating a rigid matrix that effectively immobilizes the counter‐ions (cations). This kinetic trapping effect significantly suppresses their spontaneous diffusion into the semiconductor channel during the relaxation phase, thereby preventing the neutralization of TFSI − dopants and preserving the induced polarons for superior non‐volatile retention. Meanwhile, the small‐molecule IL acts as a plasticizer to ensure sufficient ion mobility for gate voltage response. Consequently, the optimized device (40 wt.% PIL) achieves superior performance, exhibiting a synaptic state retention of 31.71% after 30 s, a nearly fivefold enhancement over the pure ionic liquid control. This kinetic control also significantly reduces the nonlinearity ( NL ) value for long‐term potentiation by 49.3%. In artificial neural network simulations, the device achieves a high recognition accuracy of 90.1%. This work demonstrates that kinetic regulation is a robust strategy to optimize state retention while maintaining sufficient response characteristics.