These permanently ionic, viologen-based polymers of intrinsic microporosity (PIMs) serve as as a standalone supercapacitor electrode material with energy-storing applications. There is a growing demand for electrically powered automobiles, consumer electronics, medical devices and other high-power density applications. However, the ability to meet these needs is challenging due to the limitations of current nonporous viologen energy storage materials. Current ionic high-capacity energy storage relies on electrochemical capacitive energy storage, operating by accumulating ions at an electrically active interface under an applied bias. A first-class material design is significant for super-capacitive purposes, especially for short-term energy storage. At the device level, the porous polymers function as standalone supercapacitor electrode materials. The microporous material is also useful for battery applications, with the current global market valued at US $7.0 billion and projected to grow to US $17.2 billion1. As car manufacturers increasingly shift toward electric vehicles, the demand for supercapacitors in regenerative braking systems is rising dramatically.
Researchers at the University of Florida have designed microporous polymers with super-capacitive properties, transforming energy storage at the material level. This innovation in synthesis and at the device-level design helps reduce manufacturing costs while preserving the large-scale fabrication advantages. These polymers can be used in numerous applications and offer competitive advantages over non-porous viologen polymers.
Viologen-based polymers of intrinsic microporosity enable supercapacitive energy storage for applications like battery storage, regenerative braking, burst-mode power, and airplane takeoff thrust
Organic energy storage materials are highly attractive for high-power density applications, owing to their synthetic tunability, compatibility with biological environments and are derived from widely available precursors. However, traditional organic supercapacitors often fall short in terms of cycling stability, power density, and manufacturability, all crucial in deployment. Researchers at the University of Florida have developed viologen-based polymers with intrinsic microporosity, designed for high-efficiency energy storage applications.
Viologen-based polymers contain permanent voids that contribute to their porous design. Spirobisindane diamine (SBIDA) serves as the contorted unit of the polymer, responsible for creating energy-storing pores. Imperfect stacking of the polymer chains leads to the formation of pores in between The synthetic protocol begins with SBIDA synthesis, after which the resulting diamine is reduced. The products include a mixture of two regioisomers, which do not require purification. A final reaction with additional reagents results in a high yield of over 80%. Carbon dioxide isotherms confirm microporosity of the polymers due to the low pressure observed during CO2 uptake. Additionally, high capacities are retained after 10,000 charge-discharge cycles. These polymers are significant for superapacitive purposes, particularly for short-term energy storage.