Toward 6G Zero-Energy Internet of Things: Standards, Trends, and Recent Results

6G presents new opportunities to enrich the cellular ecosystem by introducing battery-less Zero-energy Internet of things (ZE-IoT) devices, thus unleashing an era of massive, sustainable, and smart connectivity. This explains the increased interest in ZE-IoT in academia and industry. The road to a 6G future empowered by ZE-IoT entails cohesive efforts in the realm of standardization, academic research, and industrial trials, which are synergistic with the anticipated market demands and the dominant technology direction. In this article, we provide a holistic view of a 6G ZE-IoT future, informed by the ongoing standardization activities in the 3rd generation partnership project (3GPP) for ZE-IoT, the role of the emerging technology trends, such as digital twins and artificial intelligence, and the technical challenges in integrating ZE-IoT into the cellular ecosystem. Finally, we present recent research results to address some of the discussed challenges.