With the rapid development of the electric vehicle industry in recent years, the use of lithium batteries is growing rapidly. From 2015 to 2040, the production of lithium-ion batteries for electric vehicles could reach 0.33 to 4 million tons. It is predicted that a total of 21 million end-of-life lithium battery packs will be generated between 2015 and 2040. Spent lithium batteries can cause pollution to the soil and seriously threaten the safety and property of people. They contain valuable metals, such as cobalt and lithium, which are nonrenewable resources, and their recycling and treatment have important economic, strategic, and environmental benefits. Estimations show that the weight of spent electric vehicle lithium-ion batteries will reach 500,000 tons in 2020. Methods for safely and effectively recycling lithium batteries to ensure they provide a boost to economic development have been widely investigated. This paper summarizes the recycling technologies for lithium batteries discussed in recent years, such as pyrometallurgy, acid leaching, solvent extraction, electrochemical methods, chlorination technology, ammoniation technology, and combined recycling, and presents some views on the future research direction of lithium batteries.

Sewage sludge and waste biomass are unavoidable byproducts of municipal and industrial processes. Both materials have significant carbon contents. Activated coke with a developed pore structure can be obtained after its physical activation. In this study, sewage sludge and waste poplar bark were used as precursor materials to prepare activated coke by steam, carbon dioxide gas, and their mixtures. The effects of different concentrations of activation gas on the activated coke product were investigated. Through nitrogen adsorption analysis, it was found that activated coke has a higher specific surface area and better pore structure when activated in gas containing 20% steam. The activated coke prepared by carbon dioxide gas activation has higher microporosity than that prepared by steam activation. Infrared spectrum analysis shows that steam activation is beneficial to the formation of free hydroxyl functional groups. Through scanning electron microscopy analysis, the pores of activated coke prepared by steam activation appeared to extend deeper in the structure of the coke, while the pores of activated coke prepared by carbon dioxide activation appeared to have fine circular structures. The activated coke prepared by the activation of mixed gas appeared to have ablated particles on the surface due to the ablation of the pore structure. In order to prepare activated coke with excellent adsorption performance, the physical and chemical properties of activated coke under different activation conditions were studied in detail.

The effect of heat released during CaO adsorption on sorption-enhanced steam methane reforming for hydrogen production is insufficiently understood. On this basis, Aspen Plus is used to study the effect of steam methane reforming on hydrogen production without/with CaO. At 700 °C and an O₂ inflow of 7 mol/h, the molar flow and molar percentages of H₂ are 20.62 and 67.35%. After adding CaO, at 700 °C with 4.5 mol/h of CaO, the heat release of CaO adsorption is 1.32 MJ/h, and the O₂ inflow reduces to 4.3 mol/h. The molar flow and molar percentage of H₂ are 22.80 mol/h and 85.94%. When 1.2 mol/h CH₄ is combusted for CaCO₃ decomposition in the calciner, regenerated CaO is transferred to the reforming reactor for calcium cycling, which consumes 2.4 mol/h of O₂. For the entire cycle, 6.7 mol/h of O₂.