High-value recycling of photovoltaic waste graphite (WG) is an effective path to achieve "carbon neutrality". However, the current most adopted methods are landfilling, incineration and leaching, which can lead to undesirable environmental contamination and waste of resources. Here, an energy-efficient and high-value flash recycling strategy is developed in which photovoltaic WG is converted to high-capacity and high-rate graphite anode for lithium-ion batteries (LIBs) in milliseconds. Ultra-high temperatures (>
3000 K) were provided by flash joule heat to remove harmful impurities in the PV waste graphite, while improving the graphitization degree of WG and the (002) layer spacing of WG, making the upcycled graphite more suitable for lithium-ion (Li