Lithium iron phosphate(LiFePO_(4),LFP)batteries have shown extensive adoption in power applications in recent years for their reliable safety,high theoretical capability and low cost.Nevertheless,the finite lifespan o...Lithium iron phosphate(LiFePO_(4),LFP)batteries have shown extensive adoption in power applications in recent years for their reliable safety,high theoretical capability and low cost.Nevertheless,the finite lifespan of these batteries necessitates the future processing of a significant number of spent LFP batteries,underscoring the urgent need for the development of both efficient and eco-friendly recycling methods.This study combines the advantages of wet leaching and direct regeneration methods,leveraging citric acid's multifaceted role to streamline the combined leaching and hydrothermal processes.Results indicate that citric acid efficiently leaches all elements from spent LFP batteries.Furthermore,through its unique structure,it enhances hydrothermal regeneration by stabilizing metal ions and controlling crystal growth,and also acts as a carbon source for the surface carbon coating of regenerated LFP(RLFP).The R-LFP shows outstanding electrochemical stability,achieving a discharge capacity of 155.1 mAh.g^(-1)at 0.1C,with a capacity retention rate of 93.2%after 300 cycles at 1C.Furthermore,economic and environmental analyses demonstrate this method's superior cost-effectiveness and sustainability.Therefore,the method proposed in this study is efficient,simple and avoids the complex process of element separation,innovatively using a single reagent to achieve closed-loop recycling of LFP batteries,providing a novel and effective solution for the resource sustainability application.展开更多
In this paper,a visible light-responsive Sn^(2+)and N co-doped TiO_(2)photocatalyst was prepared by facile one-pot hydrothermal method.All as-prepared samples were characterized in detail by a series of characterizati...In this paper,a visible light-responsive Sn^(2+)and N co-doped TiO_(2)photocatalyst was prepared by facile one-pot hydrothermal method.All as-prepared samples were characterized in detail by a series of characterization approaches.The results showed that the Sn^(2+)and N elements were co-doped into TiO_(2),while the catalyst still maintains anatase crystal structure and gets irregular little nanocluster in diameter of 9–10 nm with higher specific surface area.The absorption edge of Sn^(2+)and N co-doped TiO_(2)extends to the visible light region.Compared with Sn^(2+)-doped TiO_(2)and N-TiO_(2),the absorption edges have obvious red-shift of about 50 and 70 nm,respectively.The synergistic effect of O 2p-N 2p and O 2p-Sn 5s hybridization to form impurity levels is the main reason for the red-shift.The hydrogen production performance of the Sn^(2+)and N co-doping TiO_(2)(n(N)/n(Ti)=1)catalyst reached the maximum value of 0.37 mmol·h^(-1)·g^(-1)under visible light,which is higher than that of N-doped TiO_(2)and SnTiO_(2)-doped TiO_(2)singly.This result is due to the wider visible light region-responsive ability of Sn^(2+)and N codoped into TiO_(2).Furthermore,mild hydrothermal methods will not make the Sn^(2+)oxidized to Sn^(4+),which make the catalysts still maintain high photocatalytic performance.This work provides a simple and mild method for the preparation of dual-element co-doped TiO_(2)with high crystallinity,excellent performance and broad application prospects.展开更多
基金financially supported by the Natural Science Foundation of China(No.22162007)the Science and Technology Supporting Project of Guizhou Province(Nos.[2021]480 and[2023]379)+1 种基金Wengfu(Group)Co.,Ltd.Technology Development Project(No.WH-220787(YF))the project from Guizhou Institute of Innovation and development of dual-carbon and new energy technologies(No.DCRE-2023-05)。
文摘Lithium iron phosphate(LiFePO_(4),LFP)batteries have shown extensive adoption in power applications in recent years for their reliable safety,high theoretical capability and low cost.Nevertheless,the finite lifespan of these batteries necessitates the future processing of a significant number of spent LFP batteries,underscoring the urgent need for the development of both efficient and eco-friendly recycling methods.This study combines the advantages of wet leaching and direct regeneration methods,leveraging citric acid's multifaceted role to streamline the combined leaching and hydrothermal processes.Results indicate that citric acid efficiently leaches all elements from spent LFP batteries.Furthermore,through its unique structure,it enhances hydrothermal regeneration by stabilizing metal ions and controlling crystal growth,and also acts as a carbon source for the surface carbon coating of regenerated LFP(RLFP).The R-LFP shows outstanding electrochemical stability,achieving a discharge capacity of 155.1 mAh.g^(-1)at 0.1C,with a capacity retention rate of 93.2%after 300 cycles at 1C.Furthermore,economic and environmental analyses demonstrate this method's superior cost-effectiveness and sustainability.Therefore,the method proposed in this study is efficient,simple and avoids the complex process of element separation,innovatively using a single reagent to achieve closed-loop recycling of LFP batteries,providing a novel and effective solution for the resource sustainability application.
基金This study was financially supported by the Natural Science Foundation of China(No.21663009)the National Key R&D Projects of China(No.2018YFC1801706-01)the Science and Technology Supporting Project of Guizhou Province(Nos.[2019]2835 and[2021]480).
文摘In this paper,a visible light-responsive Sn^(2+)and N co-doped TiO_(2)photocatalyst was prepared by facile one-pot hydrothermal method.All as-prepared samples were characterized in detail by a series of characterization approaches.The results showed that the Sn^(2+)and N elements were co-doped into TiO_(2),while the catalyst still maintains anatase crystal structure and gets irregular little nanocluster in diameter of 9–10 nm with higher specific surface area.The absorption edge of Sn^(2+)and N co-doped TiO_(2)extends to the visible light region.Compared with Sn^(2+)-doped TiO_(2)and N-TiO_(2),the absorption edges have obvious red-shift of about 50 and 70 nm,respectively.The synergistic effect of O 2p-N 2p and O 2p-Sn 5s hybridization to form impurity levels is the main reason for the red-shift.The hydrogen production performance of the Sn^(2+)and N co-doping TiO_(2)(n(N)/n(Ti)=1)catalyst reached the maximum value of 0.37 mmol·h^(-1)·g^(-1)under visible light,which is higher than that of N-doped TiO_(2)and SnTiO_(2)-doped TiO_(2)singly.This result is due to the wider visible light region-responsive ability of Sn^(2+)and N codoped into TiO_(2).Furthermore,mild hydrothermal methods will not make the Sn^(2+)oxidized to Sn^(4+),which make the catalysts still maintain high photocatalytic performance.This work provides a simple and mild method for the preparation of dual-element co-doped TiO_(2)with high crystallinity,excellent performance and broad application prospects.
