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 nearby_text_caption False 0.82 [303.89, 48.4, 254.45, 213.72] Redox changes on cycling Fig. 1 | Structural characterization and electrochemical data for Li 1.2 Ni0.13 Co0.13 Mn0.54 O2. a , Li 1.2 Ni0.13 Co0.13 Mn0.54 O2 with a layered R 3m structure, in-plane ordering of Li/Ni and Co/Mn giving rise to the… Fig. 1 | Structural characterization and electrochemical data for Li 1.2 Ni0.13 Co0.13 Mn0.54 O2. a , Li 1.2 Ni0.13 Co0.13 Mn0.54 O2 with a layered R 3m structure, in-plane ordering of Li/Ni and Co/Mn giving rise to the honeycomb superstructure ordering. Li atoms are represented in blue, TM in purple and oxygen in red. b , PXRD data and refinement to the R 3m crystal structure. c , Load curves for Li 1.2 Ni0.13 Co0.13 Mn0.54 O2, cycled between 2.0 V and 4.8 V at 100 mA g -1 for 100 cycles. 2 figure Fig. 2 3 sequence_or_inferred_caption False 0.82 [95.03, 49.21, 410.23, 456.31] Redox changes on cycling Fig. 2 | Evolution in bulk O-redox activity over 2nd and 100th cycles. a , d , Load curves for the 2nd ( a ) and 100th ( d ) cycles for Li 1.2 Mn0.54 Co0.13 Ni0.13 O2, with the states of charge studied. b , e , RIXS spe… Fig. 2 | Evolution in bulk O-redox activity over 2nd and 100th cycles. a , d , Load curves for the 2nd ( a ) and 100th ( d ) cycles for Li 1.2 Mn0.54 Co0.13 Ni0.13 O2, with the states of charge studied. b , e , RIXS spectra at 531.5 eV collected over the 2nd ( b ) and 100th ( e ) cycles. c , f , Variation in intensity of the molecular O 2 signal in the RIXS spectra over the 2nd ( c ) and 100th ( f ) cycles, as determined by principal component analysis (Methods). Data are presented as mean ± standard deviation with a sample size of 15. P, pristine. 3 figure Fig. 3 3 nearby_text_caption False 0.82 [347.62, 572.31, 181.51, 123.37] Redox changes on cycling Fig. 3 | Evolution in amount of trapped O 2 over cycling. Variation in intensity of the molecular O 2 signal from RIXS over cycling in the fully charged (FC) and fully discharged (FD) states. The amount of O 2 formed in… Fig. 3 | Evolution in amount of trapped O 2 over cycling. Variation in intensity of the molecular O 2 signal from RIXS over cycling in the fully charged (FC) and fully discharged (FD) states. The amount of O 2 formed in the charged materials decreases with cycling and there is increasing evidence of O 2 that is not reduced on discharge. Data are presented as mean ± standard deviation with a sample size of 15. 4 figure Fig. 4 4 sequence_or_inferred_caption False 0.82 [84.76, 55.16, 430.21, 324.23] Redox changes on cycling Fig. 4 | Formation of voids and large diamagnetic Li-rich regions over cycling. a -c , ADF-STEM images showing single grains of the pristine ( a ), 2nd discharge ( b ) and 100th discharge ( c ) material showing the form… Fig. 4 | Formation of voids and large diamagnetic Li-rich regions over cycling. a -c , ADF-STEM images showing single grains of the pristine ( a ), 2nd discharge ( b ) and 100th discharge ( c ) material showing the formation of voids about 4-12 nm in diameter over extended cycling. d , 129 Xe NMR experiments. Samples were extracted from cells and infiltrated with Xe gas to probe the open porosity. e , 129 Xe NMR of the pristine, 2nd discharge and 100th discharge materials. The orange region highlighted indicates the presence of open voids of 17 nm diameter and greater after 100 cycles. δ iso , isotropic chemical shift. f , g , 6 Li ( f ) and 17 O ( g ) NMR isolating slow and fast relaxing environments. The sharp peaks at 0 ppm in the 6 Li and slow relaxing 17 O NMR spectra indicate the formation of large diamagnetic Li-rich regions on extended cycling. 5 figure Fig. 5 5 sequence_or_inferred_caption False 0.82 [90.45, 53.92, 422.97, 266.9] The contents of the closed voids Fig. 5 | Partial reduction of O 2 trapped in voids to form Li-coordinated O 2on the 100th discharge. a , b , 17 O NMR spectra isolating fast ( a ) and slow ( b ) relaxing 17 O environments. The sharp peaks in a are assi… Fig. 5 | Partial reduction of O 2 trapped in voids to form Li-coordinated O 2on the 100th discharge. a , b , 17 O NMR spectra isolating fast ( a ) and slow ( b ) relaxing 17 O environments. The sharp peaks in a are assigned to trapped molecular O2, which decrease in intensity on discharge. There is still evidence of some residual molecular O 2 in the discharged sample, δ cg ( 17 O2) = 2,770 ppm. In b the slow relaxation 17 O is dominated by oxide environments coordinated to paramagnetic TM ions (TM-O 2-), δ cg = 2,100-2,300 ppm. After discharge, a new 17 O environment is formed corresponding to oxide surrounded by Li (that is, Li-O 2) created by the reduction of O 2 in the voids and reinsertion of Li + into the voids coordinated by the O 2, centred at δ cg = 0 ppm. D 1 , relaxation delay. c , Large voids accommodating O2 are partially repopulated by Li + on discharge. Most O 2 is reduced to O 2but some residual O 2 remains. 6 figure Fig. 6 6 direct_caption_ref False 0.82 [90.07, 51.04, 426.68, 451.81] O2 loss and residual trapped O 2 explain voltage fade Fig. 6 | Voltage fade mechanism. a , b , Second cycle: reversible O-redox involves the formation of molecular O 2 trapped in small vacancy clusters throughout the particle. O 2 molecules are fully reduced to O 2on disch… Fig. 6 | Voltage fade mechanism. a , b , Second cycle: reversible O-redox involves the formation of molecular O 2 trapped in small vacancy clusters throughout the particle. O 2 molecules are fully reduced to O 2on discharge forming small diamagnetic Li-rich regions. c , d , One-hundreth cycle: further TM migration 7 figure Docling Figure 7 11 missing_caption False 0.55 [74.64, 48.22, 451.05, 171.33] Additional information 8 figure Docling Figure 8 12 missing_caption False 0.55 [40.53, 43.18, 519.06, 414.28] Additional information 9 figure Docling Figure 9 13 missing_caption False 0.55 [121.2, 48.45, 359.5, 242.87] Additional information 10 figure Docling Figure 10 13 missing_caption False 0.55 [162.62, 318.25, 273.43, 326.44] Additional information 11 figure Docling Figure 11 14 missing_caption False 0.55 [39.56, 48.92, 519.99, 168.71] Additional information 12 figure Docling Figure 12 15 missing_caption False 0.55 [109.31, 48.89, 381.27, 379.96] Additional information 13 figure Docling Figure 13 16 missing_caption False 0.55 [39.49, 46.62, 521.69, 254.03] Additional information 14 figure Docling Figure 14 17 missing_caption False 0.55 [39.98, 48.83, 518.9, 166.57] Additional information 15 figure Docling Figure 15 18 missing_caption False 0.55 [38.88, 47.95, 521.05, 251.37] Additional information 16 table Docling Table 16 20 missing_caption False 0.55 [173.78, 72.16, 253.63, 103.49] Extended Data Table 2 | Rietveld Refinement parameters of powder X-ray diffraction data for Li 1.2 Ni0.13 Co0.13Mn0.54O2