Portable energy storage is a key component of modern energy storage. Environmental pollution control during its recycling and processing is crucial for promoting a circular economy and green development. From pretreatment to final resource utilization, the entire process requires technological optimization and management innovation to minimize the release of hazardous substances, achieving both environmental benefits and resource efficiency.
Safe collection and sorting are paramount in recycling. Portable energy storage typically contains lithium-ion batteries, electronic components, and plastic casings. If discarded carelessly, the electrolyte, heavy metals (such as cobalt and nickel), and organic solvents in the batteries can leach into soil and water sources, causing long-term pollution. Professional recycling organizations ensure centralized management of used equipment by establishing community collection points and collaborating with retailers on return-to-factory programs. During the sorting process, battery types (such as ternary lithium and lithium iron phosphate) and damage levels must be distinguished to avoid safety risks associated with mixing different chemical systems, laying the foundation for subsequent processing.
The core of the pretreatment stage is to reduce environmental risks during processing. For live batteries, nitrogen-protected crushing technology is used to disassemble the battery casing in a low-oxygen environment to prevent electrolyte volatilization and short-circuit fires. The crushed material is screened to separate non-metallic components, such as the diaphragm and plastic casing. The metal casing then enters the smelting process. Physical isolation and inert gas protection during this stage effectively block the diffusion pathways of heavy metals and organic pollutants, reducing volatile organic compound (VOC) emissions.
The extraction of valuable metals is a key step in resource recycling and a key area of environmental pollution control. Hydrometallurgy uses acid or alkaline leaching to dissolve lithium, cobalt, nickel, and other metals in battery cathode materials into ionic solutions. These solutions are then purified into metal salts through precipitation and extraction. This process requires strict control of acid and alkali dosage and wastewater treatment to prevent leakage of highly corrosive liquids. Pyrometallurgy separates metals from impurities through high-temperature smelting, but requires a flue gas purification system to remove pollutants such as dioxins and particulate matter. The currently mainstream "pyrometallurgical + hydrometallurgical" combined process uses pyrometallurgy for initial metal enrichment followed by hydrometallurgical deep purification. This approach not only improves recovery rates (over 90% for lithium and over 98% for cobalt and nickel) but also reduces the environmental impact of a single process.
The harmless treatment of graphite and electrolyte is an often overlooked step. Pyrolysis technology decomposes organic binders in the electrolyte at temperatures of 550-600°C, converting harmful substances like fluoride into harmless salts. After exhaust gas treatment in a regenerative thermal oven (RTO), the VOC removal rate exceeds 95%. The separated graphite is purified and used for anode material regeneration, reducing reliance on virgin graphite ore. Lithium hexafluorophosphate in the electrolyte is converted to phosphate through a neutralization reaction, mitigating the toxic effects of fluorine on the ecosystem.
Optimization of physical sorting technology further enhances resource utilization and environmental friendliness. A magnetic separator separates ferromagnetic materials, a gravity separator separates copper and aluminum based on density differences, and a screening device classifies black powder (a mixture of lithium, cobalt, and nickel) by particle size. A negative pressure conveying system is used throughout the entire process, transporting materials through closed pipelines to prevent dust leakage. An intelligent control system monitors oxygen concentration, temperature, and particulate matter emissions in real time to ensure that the treatment process meets environmental standards.
During the final disposal phase, recyclables and hazardous waste must be strictly separated. The extracted metal salts are returned to the battery supply chain, and the plastic casings are cleaned and shredded before being used to manufacture low-end plastic products. Unrecyclable electrolyte residues, separators, and other materials are solidified and landfilled to prevent heavy metal leaching. Material flow analysis (MFA) optimizes resource paths throughout the entire process, enabling over 95% of the materials in portable energy storage to be recycled, significantly reducing the pressure on virgin resource extraction.
Both policy and market drivers provide long-term guarantees for environmentally friendly disposal. Through the Extended Producer Responsibility (EPR) system, the government requires manufacturers to participate in the development of a recycling system and provides tax breaks for environmentally friendly disposal companies. Rising consumer awareness is driving more people to choose formal recycling channels, forming a closed cycle of "production-use-recycling-remanufacturing." Against this backdrop, the recycling and disposal of portable energy storage is shifting from "end-of-pipe treatment" to "full lifecycle management," providing a replicable model for the energy storage industry's green transformation.
