asset_index element_type label page caption_source suppress_in_index duplicate_of duplicate_reason region_rescue_reason visual_group_id parent_visual_label parent_visual_type confidence bbox section caption_preview caption 1 figure Fig. 1 2 direct_caption_ref False 0.82 [86.93, 490.31, 426.74, 233.04] Recycling strategies for spent LIBs Fig. 1 | A comparison of spent LIB recycling technologies at different stages of development. Metallurgical recycling processes typically downcycle materials, underscoring the need for next-generation recycling technolo… Fig. 1 | A comparison of spent LIB recycling technologies at different stages of development. Metallurgical recycling processes typically downcycle materials, underscoring the need for next-generation recycling technologies that preserve and even upcycle material value. 2 figure Fig. 2 7 sequence_or_inferred_caption False 0.82 [38.75, 108.87, 522.84, 251.83] Protocol Fig. 2 | The overall experimental design of this protocol. The main experimental process includes the following: (1) disassembling spent LIBs to collect and pre-treat the spent cathode materials; (2) calculating the req… Fig. 2 | The overall experimental design of this protocol. The main experimental process includes the following: (1) disassembling spent LIBs to collect and pre-treat the spent cathode materials; (2) calculating the required additives on the basis of failure analysis results and the target product composition; and (3) selecting an appropriate method for direct recycling or upcycling. 3 figure Fig. 3 27 sequence_or_inferred_caption False 0.82 [36.88, 251.39, 522.84, 447.3] Failure analysis of spent cathode materials Fig. 3 | Failure analysis of spent cathode materials. a , b , Digital photos of the S-LMO pouch cell ( a ) and electrodes ( b ). c , An SEM image of the cross section of S-LMO electrode (scale bar, 2 μm). d , A digital … Fig. 3 | Failure analysis of spent cathode materials. a , b , Digital photos of the S-LMO pouch cell ( a ) and electrodes ( b ). c , An SEM image of the cross section of S-LMO electrode (scale bar, 2 μm). d , A digital photo of the S-LMO powder. e , SEM images of typical failure characteristics of the cathode material (from left Spent 2 Ah pouch cell LMO cathode disassembled from spent pouch cell Spent LMO cathode powder Residual binder and impurities Broken particles Intragranular cracks to right: scale bars, 2 μm, 300 nm, 1 μm and 500 nm, respectively). f , Rietveld refinement of XRD pattern of S-LMO. g , A comparison of Li content in S-LMO and C-LMO analyzed via ICP-OES. h , Mn 2 p XPS spectra collected from the spent Gr anode electrode. i , HRTEM analysis of S-LMO (scale bar, 5 nm). 4 figure Fig. 4 28 sequence_or_inferred_caption False 0.82 [37.25, 109.69, 521.69, 301.09] Protocol Fig. 4 | Structural characterization of regenerated LiMn 2O4 cathode materials. a , b , Rietveld refinement of XRD patterns of R-LMO-SS ( a ) and R-LMOJH ( b ) (insets, SEM images of R-LMO-SS ( a ) and R-LMO-JH ( b ); s… Fig. 4 | Structural characterization of regenerated LiMn 2O4 cathode materials. a , b , Rietveld refinement of XRD patterns of R-LMO-SS ( a ) and R-LMOJH ( b ) (insets, SEM images of R-LMO-SS ( a ) and R-LMO-JH ( b ); scale bars, 100 nm ( a ) and 200 nm ( b )). c , EPR spectrums of R-LMO-SS and R-LMO-JH. d , e , HRTEM analysis of R-LMO-SS ( d ) and R-LMO-JH ( e ) (scale bars ( d , e ), 5 nm). 5 figure Fig. 5 29 direct_caption_ref False 0.82 [38.15, 110.61, 363.67, 269.56] Protocol Fig. 5 | Electrochemical performance of regenerated LiMn 2O4 cathode materials. a , Galvanostatic charge/discharge curves of S-LMO, R-LMO-SS and R-LMO-JH in the voltage range of 3.0-4.5 V at 0.1 C. b , Cycling performan… Fig. 5 | Electrochemical performance of regenerated LiMn 2O4 cathode materials. a , Galvanostatic charge/discharge curves of S-LMO, R-LMO-SS and R-LMO-JH in the voltage range of 3.0-4.5 V at 0.1 C. b , Cycling performance of S-LMO, R-LMO-SS and R-LMO-JH at 1 C. c , Rate performance of S-LMO, R-LMO-SS and R-LMO-JH at various current densities. 6 figure Fig. 6 30 sequence_or_inferred_caption False 0.82 [37.3, 109.45, 522.29, 294.73] Protocol Fig. 6 | Structural characterization of upcycled high-voltage cathode material LiNi 0.5 Mn1.5 O4. a , XRD patterns of upcycled precursors and products (powder diffraction file (PDF); insets show digital photos of the co… Fig. 6 | Structural characterization of upcycled high-voltage cathode material LiNi 0.5 Mn1.5 O4. a , XRD patterns of upcycled precursors and products (powder diffraction file (PDF); insets show digital photos of the corresponding powders). b , Rietveld refinement of XRD pattern of U-LNMO. c , EPR spectrums of U-LNMO and C-LNMO. d , SEM image and EDS mapping of U-LNMO (scale bar, 500 nm). e , EDS line scan of the internal section of U-LNMO. f , HRTEM analysis of U-LNMO (scale bar, 5 nm). 7 figure Fig. 7 31 direct_caption_ref False 0.82 [38.04, 111.03, 363.14, 263.74] Protocol Fig. 7 | Electrochemical performance of upcycled high-voltage cathode material LiNi 0.5 Mn1.5 O4. a , Galvanostatic charge/discharge curve of U-LNMO in the voltage range of 3.5-4.9 V at 0.1 C (The inset is the correspon… Fig. 7 | Electrochemical performance of upcycled high-voltage cathode material LiNi 0.5 Mn1.5 O4. a , Galvanostatic charge/discharge curve of U-LNMO in the voltage range of 3.5-4.9 V at 0.1 C (The inset is the corresponding d Q /d V curve). b , Cycling performance of U-LNMO and C-LNMO at 1 C. c , The rate performance of U-LNMO and C-LNMO at various current densities. 8 figure Fig. 8 32 sequence_or_inferred_caption False 0.82 [38.26, 109.52, 521.83, 295.74] Protocol Fig. 8 | Structural characterization of upcycled Li-rich Mn-based cathode material Li 1.2 Ni0.2 Mn0.6O2. a , XRD patterns of upcycled precursors and products (the insets show digital photos of the corresponding powders.… Fig. 8 | Structural characterization of upcycled Li-rich Mn-based cathode material Li 1.2 Ni0.2 Mn0.6O2. a , XRD patterns of upcycled precursors and products (the insets show digital photos of the corresponding powders.) b , Rietveld refinement of XRD pattern of U-LRMNMO. c , EPR spectrums of U-LRM and C-LRM. d , SEM image and EDS mapping of U-LRM (scale bar, 500 nm). e , EDS line scan of the internal section of U-LRM. f , HRTEM analysis of U-LRM (scale bar, 5 nm). 9 figure Fig. 9 33 direct_caption_ref False 0.82 [37.67, 110.21, 365.32, 269.83] Protocol Fig. 9 | Electrochemical performance of upcycled Li-rich Mn-based cathode material Li 1.2 Ni0.2Mn0.6O2. a , Galvanostatic charge-discharge curve of U-LRM in the voltage range of 2.0-4.8 V at 0.1 C (the inset is the corr… Fig. 9 | Electrochemical performance of upcycled Li-rich Mn-based cathode material Li 1.2 Ni0.2Mn0.6O2. a , Galvanostatic charge-discharge curve of U-LRM in the voltage range of 2.0-4.8 V at 0.1 C (the inset is the corresponding d Q /d V curve). b , Cycling performance of U-LRM and C-LRM at 1 C. c , Rate performance of U-LRM and C-LRM at various current densities. 10 table Table 1 3 nearby_text_caption False 0.82 [38.87, 139.09, 347.22, 60.53] Table 1 | Comparison of key parameters of spent LIB recycling technologies at different stages of development Table 1 | Comparison of key parameters of spent LIB recycling technologies at different stages of development Table 1 | Comparison of key parameters of spent LIB recycling technologies at different stages of development 11 table Table 2 4 direct_caption_ref False 0.82 [38.75, 129.7, 377.11, 85.24] Protocol Table 2 | Comparison of key parameters of five direct regeneration methods Table 2 | Comparison of key parameters of five direct regeneration methods 12 table Table 3 17 nearby_text_caption False 0.82 [38.9, 138.84, 357.34, 81.5] Table 3 | The proportion of primary materials used in various direct regeneration and upcycling processes Table 3 | The proportion of primary materials used in various direct regeneration and upcycling processes Table 3 | The proportion of primary materials used in various direct regeneration and upcycling processes 13 table Table 4 25 nearby_text_caption False 0.82 [39.06, 138.99, 306.19, 51.54] Table 4 | Basic parameter settings for electrochemical testing of different materials in this protocol Table 4 | Basic parameter settings for electrochemical testing of different materials in this protocol Table 4 | Basic parameter settings for electrochemical testing of different materials in this protocol 14 table Table 5 25 nearby_text_caption False 0.82 [38.78, 569.04, 522.87, 174.5] Table 5 | Troubleshooting Table 5 | Troubleshooting Table 5 | Troubleshooting 15 table Docling Table 15 26 missing_caption False 0.55 [38.41, 128.68, 523.65, 463.52] Table 5 (continued) | Troubleshooting 16 table Docling Table 16 35 missing_caption False 0.55 [38.93, 107.4, 523.12, 94.31] Protocol 17 table Docling Table 17 36 missing_caption False 0.55 [28.95, 531.12, 530.63, 89.47] Software and code