Solar cells show promise as energy conversion gadgets, but their extended use is limited by intermittent sunlight. Self-powered solar cell integration with an electrical energy storage system could be one solution to this problem. Therefore, we have developed a coin cell supercapacitor (SC) device based on coal-based graphitized carbon materials and integrated with solar cells to assess its efficiency for energy transformation and storage for practical validity. Supercapacitor carbon electrode was developed from a naturally abundant carbon precursor i.e. low-grade coal using molasses as binder, for the fabrication of high-quality SC devices. The fabricated supercapacitor exhibits a notable 127 F g−1 specific capacitance, maintaining 92 % of its initial value for up to 10,000 charge/discharge cycles at 5 A g−1, and a maximum energy density of 70.57 Wh kg−1 and power density of 2000.17 W kg−1. In order to create a self-sustaining power pack, the SCs (4 V) are integrated with a commercial solar cell (6 V, 750 mAh). Importantly, in the presenceof natural sunlight, the solar-powered as-fabricated supercapacitor bankcan significantly power a commercial IoT module (4–6 V, 600 mAh) demonstrating its potential for successful solar-to-electric energy transformation and storage. The findings demonstrate that solar-powered coal-based SC can be explored as an incredibly rapid future-proof energy storage technology that can help reduce energy demand in the foreseeable future.

中文翻译：

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用于太阳能超级电容器物联网应用的煤基石墨化活性炭


太阳能电池作为能量转换装置展现出良好的前景，但其长期使用受到间歇性阳光的限制。自供电太阳能电池与电能存储系统的集成可能是解决这个问题的一种方法。因此，我们开发了一种基于煤基石墨化碳材料并与太阳能电池集成的纽扣电池超级电容器（SC）装置，以评估其能量转换和存储的效率，以实现实际有效性。超级电容器碳电极是由天然丰富的碳前体（即低品位煤）开发而成，使用糖蜜作为粘合剂，用于制造高质量的超电容器。所制造的超级电容器表现出显着的 127 F g−1 比电容，在 5 A g−1 下进行多达 10,000 次充电/放电循环后仍保持其初始值的 92%，最大能量密度为 70.57 Wh kg−1 和功率密度2000.17 W kg−1。为了创建一个自我维持的电源组，SC（4 V）与商用太阳能电池（6 V，750 mAh）集成。重要的是，在自然光存在的情况下，太阳能供电的超级电容器组可以为商业物联网模块（4-6V，600mAh）提供显着的电力，展示其成功将太阳能转换和存储的潜力。研究结果表明，太阳能煤基 SC 可以被探索为一种极其快速、面向未来的储能技术，有助于在可预见的未来减少能源需求。