Chapter 15: Emerging Applications of Green Supercapacitors: A Critical Review

Increasing energy demands and the substantial dependence on carbon-based fuels have motivated researchers to consider alternative and sustainable energy resources. The availability of renewable energy sources is not restricted, but there are certain limitations, such as efficiency, intermittency, and initial cost. These restrictions have motivated researchers to develop efficient and ecofriendly energy storage methods that can render the energy economy more robust. In the current scenario, highly effective energy storage devices like supercapacitors are needed. Utilizing electrode materials synthesized by green approaches is crucial to address the prevailing challenges. Many industries require green supercapacitors. The industrial segments are energy, electronics, aerospace, packaging, environmental protection, and biomedicine. Researchers have become interested in supercapacitors because they can be utilized in “situations where batteries are being overused” and also in situations wherein high-power density (>500 W kg⁻¹) is required. Supercapacitors are a more energy-efficient option, although they have cost and performance drawbacks. Electrode materials selection that takes into account both electrical performances on the one hand and ‘sustainability performance’ on the other hand becomes important. This review will focus on greenness in terms of the green supercapacitor context. The development of the understanding and knowledge base required to bring about this greenness adoption in emerging applications is described in detail.