Requirement of autonomous energy storage systems has been increasing in today's world. Off-grid energy storage systems are the forthcoming potential devices due to their noteworthy advances of negligible unwanted energy losses, off-grid operation, light-weight, small in-size, and so forth. Electrochemical capacitors known as supercapacitors (SCs) show unique energy storage performance in terms of high power density, rapid charge/discharge characteristic and long cycling life, thereby they have been finding a special research attention in the scientific community. This article highlights recent developments of off-grid SCs – which are classified into mechanically rechargeable SCs, optically rechargeable SCs and thermally rechargeable SCs. The details working mechanisms along with their performances of these systems were discussed. In addition, this article covers recently developed some of the advanced integrated off-grid systems including integrated SCs with solar cells and nanogenerators, for simultaneous harvesting optical and mechanical energies for charge storage. Finally, the research outlooks and possible research pathways of these off-grid systems are addressed that requires for continuous powering the modern autonomous electronic systems.

在当今世界，对自动储能系统的需求一直在增长。离网储能系统是即将到来的潜在设备，因为它们在可忽略的无用能量损失，离网运行，重量轻，尺寸小等方面的显着进步。被称为超级电容器（SC）的电化学电容器在高功率密度，快速充电/放电特性和长循环寿命方面表现出独特的储能性能，因此在科学界引起了特别的研究关注。本文重点介绍离网SC的最新发展-分为机械可充电SC，光学可充电SC和热可充电SC。讨论了这些系统的详细工作机制及其性能。此外，本文介绍了最近开发的一些先进的集成离网系统，包括带有太阳能电池和纳米发电机的集成SC，用于同时收集光能和机械能以存储电荷。最后，解决了这些离网系统的研究前景和可能的研究途径，这需要为现代自主电子系统持续供电。