Compositions for electrochemical energy storage

Abstract

Disclosed are methods, materials, compositions, formulations, products, and systems that pertain to energy storage devices such as Li-ion electrochemical cells and batteries. In some disclosed materials, the material has a crystal structure with one or more tetrahedral sites and a redox-inactive cation is located at each tetrahedral site. The disclosed embodiments, among other features and benefits, can be implemented to provide high-performance energy storage devices.

Description

PCT Application Attorney Docket No.: 009062.8567. WO00COMPOSITIONS FOR ELECTROCHEMICAL ENERGY STORAGE CROSS-REFERENCE TO RELATED APPLICATION

[0001] This patent document claims priority to and benefits of U. S. Provisional Application 63 / 729,905, entitled “COMPOSITIONS FOR ELECTROCHEMICAL ENERGY STORAGE,” and filed on December 9, 2024. The entire content of the above noted patent application is incorporated by reference as part of the disclosure of this patent document.TECHNICAL FIELD

[0002] This patent document is generally related to electrochemical energy storage.BACKGROUND

[0003] Lithium-ion batteries are widely used as power sources for numerous applications, ranging from portable consumer electronics to electric vehicles, due to their high energy density and long cycle life. A typical lithium-ion battery includes a positive electrode (cathode), a negative electrode (anode), an electrolyte, and a separator. The current standard anode material in commercial lithium-ion batteries is graphite. However, graphite has several challenges that can lead to a reduction in capacity and overall battery performance. Alternative materials are therefore highly desirable.SUMMARY

[0004] Disclosed herein are methods, materials, compositions, formulations, products, and systems that pertain to energy storage devices such as Li-ion electrochemical cells and batteries.

[0005] In one aspect, an active electrode material of a battery device is disclosed. The active electrode material, comprising: a metal oxide comprising niobium (Nb); and a plurality of redoxinactive cations comprising phosphorus (P), wherein: the metal oxide has a crystal structure comprising one or more tetrahedral sites, some or all of the one or more tetrahedral sites are occupied by a respective redox-inactive cation, and the active electrode material has a niobium-to-phosphorus element ratio (Nb: P) greater than 9:1.

[0006] In another aspect, an energy storage device is disclosed. The energy storage device, comprising: an anode; a cathode; and an electrolyte coupling the cathode to the anode, wherein the anode comprises an active electrode material as disclosed in the present patent document.1009062.8567. WO00\l 84663322.1PCT Application Attorney Docket No.: 009062.8567. WO00

[0007] In yet another aspect, a method of producing an active electrode material for an energy storage device is disclosed. The method, comprising: providing a niobium-based oxide having a crystal structure comprising one or more tetrahedral sites, wherein the crystal structure includes a reducible cation at each of the one or more tetrahedral sites; and replacing the reducible cation, at some or all of the one or more tetrahedral sites, with an irreducible cation comprising phosphorus, wherein the replacing of the reducible cation modifies one or more parameters of the energy storage device, wherein the one or more parameters relate to a charge storage capacity of the energy storage device.

[0008] These, and other, features and aspects are further disclosed in the present document.BRIEF DESCRIPTION OF THE DRAWINGS

[0009] FIG. 1 shows a plot of example performance data obtained in a characterization of a battery comprising a PNb11WO33material based on the disclosed technology

[0010] FIG. 2 shows example results obtained from a 2C cycling test of the PNb11WO33battery of FIG. 1.

[0011] FIG. 3 shows example results obtained from a rate test of the PNb11WO33battery of FIG. 1.

[0012] FIG. 4 shows a plot of example performance data obtained in a characterization of a battery comprising a PNb13W3O44material based on the disclosed technology.

[0013] FIG. 5 shows example results obtained from a 10C cycling test of the PNb13W3O44battery of FIG. 4.

[0014] FIG. 6 shows example results obtained from a 2C cycling test of the PNb13W3O44battery of FIG. 4.

[0015] FIG. 7 shows example results obtained from a C / 3 cycling test of the PNb13W3O44battery of FIG. 4.

[0016] FIG. 8 shows example results obtained from a rate test of the PNb13W3O44battery of FIG. 4.

[0017] FIG. 9 shows a plot of potential versus capacity data obtained for an example Nb14W3O44material based on the disclosed technology.2009062.8567. WO00\l 84663322.1PCT Application Attorney Docket No.: 009062.8567. WO00

[0018] FIG. 10 shows a plot of potential versus capacity data obtained for an example PNb13W3O44material based on the disclosed technology.

[0019] FIG. 11 shows a plot of potential versus capacity data obtained for an example PNb11WO33material based on the disclosed technology.

[0020] FIGS. 12 -27 show example data obtained from a rate test of some materials based on the disclosed technology.

[0021] FIGS. 28-33 shows example data obtained from a cycle test of some materials based on the disclosed technology.

[0022] FIG. 34 shows a31P NMR spectrum of a disclosed PNbi 1WO33 material referenced to 85% H3PO4(aq.).

[0023] FIG. 35 shows a31P NMR spectrum of a disclosed PNb13W3O44material referenced to 85% H3PO4(aq.).

[0024] FIG. 36 shows example XRD data (Cu Ka radiation) of some disclosed materials.

[0025] FIG. 37 shows example XRD data of the disclosed material PNb11WO33(top spectrum in FIG. 37) and Nb12WO33(middle spectrum in FIG. 37).

[0026] FIG. 38 shows example XRD data of the disclosed materials PNb13W3O44(top spectrum in FIG. 38) and Nb14W3O44(middle spectrum in FIG. 38).

[0027] FIG. 39 shows example XRD data of the disclosed materials PNb15W5O55(top spectrum in FIG. 39) and Nb16W5O55(middle spectrum in FIG. 39).

[0028] FIG. 40 shows example XRD data of the disclosed materials PNb17W8O69(top spectrum in FIG. 40) and Nb18W8O69(middle spectrum in FIG. 40).

[0029] FIG. 41 shows example31P NMR data of the disclosed material PNb11WO33.

[0030] FIG. 42 shows example31P NMR data of the disclosed material PNb13W3O44.

[0031] FIGS. 43-47 show example crystal structures of some materials based on the disclosed technology

[0032] FIG. 48 shows a flow chart of an example method based on the disclosed technology.3009062.8567. WO00\l 84663322.1PCT Application Attorney Docket No.: 009062.8567. WO00DETAILED DESCRIPTION

[0033] The present patent document relates to electrochemical energy storage devices, including high-performance batteries such as Li-ion batteries, and their material compositions. Some example embodiments include a Li-ion battery having an anode material that is stabilized to prevent unwanted side reactions during repeated charging and discharging of the battery. In some example embodiments, the crystal structure of the battery material is stabilized with an irreducible cation (e.g., phosphorus) on a specific position (e.g., tetrahedral position) of the crystal structure such that ion migration does not occur, thereby making the atomic structure more stable and more reversible. Various material compositions are disclosed including PNb27O70, PNb11WO33, PNb13W3O44, PNb15W5O55, PNb17W8O69, PTiNb23O62, and many substitutional variations thereof.

[0034] Some advantages of the disclosed technology include Li-ion battery anode compositions which can endow the battery with the ability to charge extremely rapidly (e.g., on the order of 5 minutes), have high charge storage capacity, be more durable for long cycle lives, and provide inherent safety. Additionally, some disclosed battery anode compositions include a stabilizing metal that is both lighter in weight and less expensive than the metals that would conventionally be located on a specific position of the crystal structure. Thus, material compositions based on the disclosed technology can be implemented to achieve batteries with higher energy density and lower cost in comparison to existing technologies. Furthermore, the disclosed embodiments can be implemented to eliminate first-cycle irreversible processes commonly observed in battery technologies.

[0035] The anode is the rate-limiting component of a lithium-ion battery. The standard commercial anode material is graphite, which cannot be operated at high power or under fast charging conditions because it cannot incorporate lithium ions rapidly enough and, as a result, can form metallic lithium deposits on its surface that propagate across the cell and cause a short circuit and lead to a battery fire. In related ways, graphite can delaminate or its delicate surface layer called the surface-interphase layer (SEI) can degrade when operated at elevated current density or temperature. It is also not stable over many thousands of cycles which is desired for certain longlife applications. Additionally, niobium-based anodes for lithium-ion batteries have been proposed. However, most of these materials contain reducible metals on a certain site (the tetrahedral site) that are reduced on the first time lithium is inserted into the material, which causes that metal to migrate to a new site in an irreversible manner. That irreversibility manifests as lost4009062.8567. WO00\l 84663322.1PCT Application Attorney Docket No.: 009062.8567. WO00capacity and, more importantly, trapping of lithium ions from the cathode, which in turn means excessive cathode must be added to this family of batteries, which lowers the energy density and comes at considerable expense. Some example embodiments, among other features and benefits, can be implemented in various applications to address the aforementioned limitations in existing technologies.

[0036] In an example embodiment, an anode material that can be implemented in a lithium-ion battery is disclosed. The crystal structure of the material is stabilized to prevent unwanted side reactions during repeated charge and discharge of the battery. In some implementations, the material is stabilized by stabilizing the crystal structure with an irreducible cation (e.g., phosphorus) on a specific position (e.g., tetrahedral position) of the crystal structure. The material can be implemented, for example, to achieve long-life, high-power and fast-charging batteries, and in lithium-ion batteries where safety is a critical metric.

[0037] Some disclosed embodiments relate to techniques to modify a material composition of an electrochemical energy storage device such as a high-performance battery are disclosed.

[0038] In some existing battery technologies, the first-cycle irreversibility causes capacity loss and, more importantly, trapping of lithium ions from the cathode, which in turns means excessive cathode must be added to this family of batteries, which lowers the energy density and comes at considerable expense. The irreversibility stems from the presence of a reducible metal cation on the tetrahedral position in the atomic structure of many niobium-based battery anode materials. The metal can vary between different compounds such as Nb2O5, Nb12WO33, Nb14W3O44, Nb16W5O55, Nb18W8O69, TiNb24O62and many variations of these materials.

[0039] In recognition of the foregoing challenges, some disclosed embodiments can be implemented to eliminate the process behind first-cycle irreversibility in high-performance battery material compositions.

[0040] In an example embodiment, modifying the material composition of an electrochemical energy storage device (e.g., a battery) comprises replacing a reducible cation in the atomic structure of the material composition with an irreducible cation. In some implementations, the irreducible cation is phosphorus, which strongly prefers a tetrahedral position in the atomic structure of a battery material composition.

[0041] Various examples of material compositions for electrochemical energy storage devices5009062.8567. WO00\l 84663322.1PCT Application Attorney Docket No.: 009062.8567. WO00are disclosed. Some example material compositions based on the disclosed technology include: PNb27O70, PNb11WO33, PNb13W3O44, PNb15W5O55, PNb17W8O69, PTiNb23O62, and many substitutional variations thereof. X-ray diffraction patterns and NMR spectra of some disclosed material compositions have been demonstrated to change in systematic ways.

[0042] Some example material compositions have a niobium-to-phosphorus (Nb: P) element ratio >9:1 or mass ratio >27.

[0043] Some example material compositions have a higher niobium (Nb) content than PNb9O25.

[0044] Some example material compositions do not crystallize in a PNbpOz crystal structure.

[0045] Some example material compositions include: PNb27O70, PNb11WO33, PNb13W3O44, PNb15W5O55, PNb17W8O69, PTiNb23O62, PNb21O54, PNb24O62, PNb46O116, and elemental substitutions thereof such as isovalent (same charge) or aliovalent (different charge) substitution for any of the metals.

[0046] Some example material compositions include carbon coating and such materials can be used as negative electrodes in batteries with various positive electrodes e.g.. including lithium with nickel and / or manganese and / or cobalt such as NMC Li(Ni,Mn,Co)O2, NCA Li(Ni,Mn,Co,Al)O2, LNO LiNiO2, LCO LiCoO2, LNMO Li(Ni,Mn)2O4, LMO LiMn2O4, LFP LiFePO4, a disordered rocksalt material (DRX), LMR Li2MnO3-Li(Ni,Mn,Co)O2.

[0047] Some disclosed materials have phosphorus on all of the tetrahedral sites. Some disclosed materials have phosphorus on all of the tetrahedral sites and only the tetrahedral sites. Such features can allow some disclosed materials to provide better energy storage performance in comparison to existing materials.

[0048] Some disclosed materials are derived from structures that have tetrahedra, and those structures (e.g., Nb28O70(i.e., H-Nb2O5), Nb12WO33, Nb14W3O44, Nb16W5O55, Nb18W8O69, TiNb24O62, Nb22O54, Nb25O62, Nb47O116) have reducible cations inside the tetrahedra. In some applications, when those reducible cations get reduced, e.g., during operation (lithiation) of a battery electrode, they are unstable and they change positions, inducing an irreversibility, low first-cycle efficiency, lower reversible capacity, irreversible lithium consumption, increased anode voltage on subsequent lithiation cycles leading to lower full cell voltage when used as an anode in a full cell battery, and poor cycling stability. Some disclosed embodiments address the foregoing challenges by replacing reducible cations inside tetrahedra of a structure with irreducible cations.6009062.8567. WO00\l 84663322.1PCT Application Attorney Docket No.: 009062.8567. WO00

[0049] Tn an example embodiment, a material composition is derived by arranging irreducible phosphorus cations onto reducible cation sites inside tetrahedra of structures such as, e.g., Nb28O70(i.e., H-Nb2O5), Nb12WO33, Nb14W3O44, Nb16W5O55, Nb18W8O69, TiNb24O62, Nb22O54, Nb25O62, Nb47O116. By causing irreducible phosphorus to be located onto those sites in accordance with disclosed techniques, reduction of the tetrahedral sites cannot occur during usual battery operation, and the material can provide higher first cycle coulombic efficiency, less irreversible lithium consumption, higher capacity, stable voltage, and a more stable cycle life. This can be demonstrated in measured voltage profiles and differential voltage profiles of the material. In an example demonstration, such profiles showed a significant difference between the first and second cycles (irreversibility) when phosphorus is not present, which disappears when phosphorus is present.

[0050] In some embodiments, an irreducible phosphorus cation is located on a portion of a tetrahedral site (e.g., >90% on the tetrahedral site, 80% on the tetrahedral site, etc.).

[0051] Some disclosed materials can be synthesized in accordance with the following example techniques.

[0052] In one example technique, the materials could be produced from distinct niobium and phosphorus precursors, preferably niobium oxide Nb20., Nb2O5with Dso particle size <10 pm, more preferably ≤ 5 μm or 0.25–5 μm; hydrous Nb2O5·H2O where = 0–10, ammonium niobium oxalate NH4NbO(C2O4)2(H2O)2·H2O where = 0–10, ammonium phosphate monobasic i.e. ammonium dihydrogen phosphate, i.e., ADP, NH4H2PO4; ammonium phosphate dibasic i.e. diammonium phosphate, i.e., DAP, (NH4)2HPO4; ammonium phosphate tribasic i.e. ammonium phosphate, (NH4)3PO4.

[0053] In another example technique, the materials could be produced with a mixed niobiumphosphorus precursor such as niobium phosphate NbOPO4or niobium phosphate hydrate NbOPO4-«H2O where n = 0-10 that is reacted with another phosphorus source such as ammonium phosphate monobasic i.e. ammonium dihydrogen phosphate, i.e.. ADP, NH4H2PO4; ammonium phosphate dibasic i.e. diammonium phosphate, i.e., DAP, (NH4)2HPO4; or ammonium phosphate tribasic i.e. ammonium phosphate, (NH4)3PO4. In some embodiments, the reaction takes place in one or more heating steps with the maximum temperature reaching a temperature in the range 800-1500 °C.

[0054] In some embodiments, the reaction takes place in one or more heating steps with the7009062.8567. WO00\l 84663322.1PCT Application Attorney Docket No.: 009062.8567. WO00maximum temperature reaching a temperature in the range 800-1500 °C.

[0055] Example P-Nb-W-O Phase Battery Performance Data

[0056] FIGS. 1-33 show examples of electrochemical battery cycling data, at various rates and voltage ranges, of some disclosed embodiments.

[0057] FIG. 1 shows a plot of example performance data obtained in a characterization of a battery comprising a PNb11WO33material based on the disclosed technology. Specifically, FIG. 1 shows cell voltage (Ecell / V) plotted against capacity for three formation cycles. The following parameters were used in the characterization: 50 um Cu current collector, 80:10:10 ratio of electrode active material to conductive carbon to polymer binder, electrode mass loading of ~1.5 mg / cm2, three cycles at C / 20 rate, consistent charge capacity of - 177 mAh / g across all three cycles.

[0058] FIG. 2 shows example results obtained from a 2C cycling test of the PNb11WO33battery of FIG. 1. Specifically, FIG. 2 shows a plot of charge (Q) versus cycle number for various cycles, with the various cycles indicated in FIG. 2 using cross or dot markers. In FIG. 2, cross markers correspond to a standard protocol with C / 20 check up cycles after C / 20 formation cycles; dot markers correspond to a modified high-rate protocol with C / 3 check up cycles and no formation cycles. The following results are demonstrated from FIG. 2: 13.7% charge capacity fade for modified protocol after 80 cycles compared to 20.9% that of standard protocol. Based on the trend in FIG. 2, the difference in capacity fading rate is increasing.

[0059] FIG. 3 shows example results obtained from a rate test of the PNb11WO33battery of FIG. 1 after formation cycles. The following parameters were used in the rate test: 3 cycles each for C / 10, C / 5, and C / 2 rate; 10 cycles each for 1C, 2C, 5C. 10C, and 20C rate.

[0060] FIG. 4 shows a plot of example performance data obtained in a characterization of a battery comprising a PNb13W3O44material based on the disclosed technology. Specifically, FIG.1 shows cell voltage per volume (Ecell / V) plotted against capacity for three formation cycles. The following parameters were used in the characterization: 10 um Cu current collector, 80: 10: 10 ratio of electrode active material to conductive carbon to polymer binder, electrode mass loading of -2.5 mg / cm2, three cycles at C / 20 rate, consistent charge capacity of -168 mAh / g across all three cycles.

[0061] FIG. 5 shows example results obtained from a 10C cycling test of the PNb13W3O44battery of FIG. 4. Specifically, FIG. 5 shows a plot of charge (Q) versus cycle number for various8009062.8567. WO00\l 84663322.1PCT Application Attorney Docket No.: 009062.8567. WO00cycles, with the various cycles indicated in FIG. 5 using cross or dot markers. Tn FIG. 5, cross markers correspond to a standard protocol with C / 20 check up cycles after C / 20 formation cycles; dot markers correspond to a modified high-rate protocol with C / 3 check up cycles and no formation cycles. The following results are demonstrated from FIG. 5: 14.5% charge capacity fade for modified protocol after 140 cycles. In the example IOC cycling test, all cell build was kept the same with electrodes from same batch of slurry.

[0062] FIG. 6 shows example results obtained from a 2C cycling test of the PNb13W3O44battery of FIG. 4. Specifically, FIG. 6 shows a plot of charge (Q) versus cycle number for various cycles, with the various cycles indicated in FIG. 6 using cross or dot markers. In FIG. 6, cross markers correspond to a standard protocol with C / 20 check up cycles after C / 20 formation cycles; dot markers correspond to a modified high-rate protocol with C / 3 check up cycles and no formation cycles. The following results are demonstrated from FIG. 5: 2.2% charge capacity fade for modified protocol after 80 cycles compared to 2.4% that of standard protocol. Based on the trend in FIG. 6, the difference in capacity fading rate is increasing.

[0063] FIG. 7 shows example results obtained from a C / 3 cycling test of the PNbi3W3O44battery of FIG. 4. Specifically, FIG. 7 shows a plot of charge (Q) versus cycle number for various cycles, with the various cycles indicated in FIG. 7 using cross (charge) or dot (discharge) markers. In the example of FIG. 7, a standard C / 3 cycle test was performed after formation cycles with check up cycles at C / 20 rate.

[0064] FIG. 8 shows example results obtained from a rate test of the PNb13W3O44battery of FIG. 4 after formation cycles. The following parameters were used in the rate test: 3 cycles each for C / 10, C / 5, and C / 2 rate; 10 cycles each for 1C, 2C, 5C. 10C. and 20C rate.

[0065] FIG. 9 shows a plot of potential versus capacity data obtained for an example Nbi4W3O44material based on the disclosed technology. Specifically, FIG. 9 shows the reversible electrochemical lithium insertion profile of the first two lithium insertion and extraction cycles of Nb14W3O44at C / 20 current density (C-rate) corresponding to 1 Li per transition metal discharge in 20 hours. FIG. 9 shows large differences between the first two cycles. In FIG. 9, 1stcycle (a) and 2ndcycle (a) show the material cycled from 2.5 to 1.2 V; 1stcycle (b) and 2ndcycle (b) show the material cycled from 2.5 to 1.0 V.

[0066] FIG. 10 shows a plot of potential versus capacity data obtained for an example9009062.8567. WO00\l 84663322.1PCT Application Attorney Docket No.: 009062.8567. WO00PNb13W3O44material based on the disclosed technology. Specifically, FIG. 10 shows the reversible electrochemical lithium insertion profile of the first three lithium insertion and extraction cycles of PNb13W3O44at C / 20 C-rate corresponding to 1 Li per transition metal discharge in 20 hours. FIG. 10 shows negligible differences between the first three cycles.

[0067] FIG. 11 shows a plot of potential versus capacity data obtained for an example PNb11WO33material based on the disclosed technology. Specifically, FIG. 11 shows the reversible electrochemical lithium insertion profile of the first three lithium insertion and extraction cycles of PNb11WO33at C / 20 C-rate corresponding to 1 Li per transition metal discharge in 20 hours. FIG. 11 shows negligible differences between the first three cycles.

[0068] FIG. 12 shows example data obtained from a rate test of some disclosed materials. Specifically, FIG. 12 shows electrochemical capacity of Nb12WO33(square markers) and PNb11WO33(circle markers) with phosphorus on the tetrahedral positions at different C-rates corresponding to 1 Li per transition metal discharge in 2 hours (C / 2) to 3 mins (20 C). In the rate test, electrodes were cycled under the same conditions from 2.7 to 1.2 V at constant current vs. Li metal counter electrodes. The following parameters were used in the test: no formation cycles; 80:15:05 ratio of electrode active material to conductive carbon to polymer binder.

[0069] FIG. 13 shows example data obtained from a rate test of some disclosed materials. Specifically, FIG. 13 shows electrochemical capacity of Nb12WO33(square markers) and PNb11WO33(circle markers) with phosphorus on the tetrahedral positions at different C-rates corresponding to 1 Li per transition metal discharge in 2 hours (C / 2) to 3 mins (20 C). In the rate test, electrodes were cycled under the same conditions from 2.7 to 1.0 V at constant current vs. Li metal counter electrodes. The following parameters were used in the test: no formation cycles; 80:15:05 ratio of electrode active material to conductive carbon to polymer binder.

[0070] FIG. 14 shows example data obtained from a rate test of some disclosed materials. Specifically, FIG. 14 shows electrochemical capacity of Nb12WO33(square markers) and PNb11WO33(circle markers) with phosphorus on the tetrahedral positions at different C-rates corresponding to 1 Li per transition metal discharge in 2 hours (C / 2) to 3 mins (20 C). In the rate test, electrodes were cycled under the same conditions from 2.7 to 1.2 V at constant current discharge and constant current constant voltage charge vs. Li metal counter electrodes. The following parameters were used in the test: no formation cycles; 80:15:05 ratio of electrode active10009062.8567. WO00\l 84663322.1PCT Application Attorney Docket No.: 009062.8567. WO00material to conductive carbon to polymer binder.

[0071] FIG. 15 shows example data obtained from a rate test of some disclosed materials. Specifically, FIG. 15 shows electrochemical capacity of Nb12WO33(square markers) and PNb11WO33(circle markers) with phosphorus on the tetrahedral positions at different C-rates corresponding to 1 Li per transition metal discharge in 2 hours (C / 2) to 3 mins (20 C). In the rate test, electrodes were cycled under the same conditions from 2.7 to 1.0 V at constant current discharge and constant current constant voltage charge vs. Li metal counter electrodes. The following parameters were used in the test: no formation cycles; 80:15:05 ratio of electrode active material to conductive carbon to polymer binder.

[0072] FIG. 16 shows example data obtained from a rate test of some disclosed materials. Specifically, FIG. 16 shows electrochemical capacity of Nb14W3O44(square markers) and PNb13W3O44(circle markers) with phosphorus on the tetrahedral positions at different C-rates corresponding to 1 Li per transition metal discharge in 2 hours (C / 2) to 3 mins (20 C). In the rate test, electrodes were cycled under the same conditions from 2.7 to 1.2 V at constant current vs. Li metal counter electrodes. The following parameters were used in the test: no formation cycles; 80:15:05 ratio of electrode active material to conductive carbon to polymer binder.

[0073] FIG. 17 shows example data obtained from a rate test of some disclosed materials. Specifically, FIG. 17 shows electrochemical capacity of Nb14W3O44(square markers) and PNb13W3O44(circle markers) with phosphorus on the tetrahedral positions at different C-rates corresponding to 1 Li per transition metal discharge in 2 hours (C / 2) to 3 mins (20 C). In the rate test, electrodes were cycled under the same conditions from 2.7 to 1.0 V at constant current vs. Li metal counter electrodes. The following parameters were used in the test: no formation cycles; 80:15:05 ratio of electrode active material to conductive carbon to polymer binder.

[0074] FIG. 18 shows example data obtained from a rate test of some disclosed materials. Specifically, FIG. 18 shows electrochemical capacity of Nb14W3O44(square markers) and PNb13W3O44(circle markers) with phosphorus on the tetrahedral positions at different C-rates corresponding to 1 Li per transition metal discharge in 2 hours (C / 2) to 3 mins (20 C). In the rate test, electrodes were cycled under the same conditions from 2.7 to 1.2 V at constant current discharge and constant current constant voltage charge vs. Li metal counter electrodes. The following parameters were used in the test: no formation cycles; 80:15:05 ratio of electrode active11009062.8567. WO00\l 84663322.1PCT Application Attorney Docket No.: 009062.8567. WO00material to conductive carbon to polymer binder.

[0075] FIG. 19 shows example data obtained from a rate test of some disclosed materials. Specifically, FIG. 19 shows electrochemical capacity of Nb14W3O44(square markers) and PNb13W3O44(circle markers) with phosphorus on the tetrahedral positions at different C-rates corresponding to 1 Li per transition metal discharge in 2 hours (C / 2) to 3 mins (20 C). In the rate test, electrodes were cycled under the same conditions from 2.7 to 1.0 V at constant current discharge and constant current constant voltage charge vs. Li metal counter electrodes. The following parameters were used in the test: no formation cycles; 80:15:05 ratio of electrode active material to conductive carbon to polymer binder.

[0076] FIG. 20 shows example data obtained from a rate test of some disclosed materials. Specifically, FIG. 20 shows electrochemical capacity of Nb12WO33(square markers) and PNb11WO33(circle markers) with phosphorus on the tetrahedral positions at different C-rates corresponding to 1 Li per transition metal discharge in 20 hours (C / 20) to 3 mins (20 C). In the rate test, electrodes were cycled under the same conditions from 2.7 to 1.2 V at constant current vs. Li metal counter electrodes. The following parameters were used in the test: C / 20 formation cycles included; 80:10:10 ratio of electrode active material to conductive carbon to polymer binder.

[0077] FIG. 21 shows example data obtained from a rate test of some disclosed materials. Specifically, FIG. 21 shows electrochemical capacity of Nb12WO33(square markers) and PNb11WO33(circle markers) with phosphorus on the tetrahedral positions at different C-rates corresponding to 1 Li per transition metal discharge in 20 hours (C / 20) to 3 mins (20 C). In the rate test, electrodes were cycled under the same conditions from 2.7 to 1.0 V at constant current vs. Li metal counter electrodes. The following parameters were used in the test: C / 20 formation cycles included; 80:10:10 ratio of electrode active material to conductive carbon to polymer binder.

[0078] FIG. 22 shows example data obtained from a rate test of some disclosed materials. Specifically, FIG. 22 shows electrochemical capacity of Nb14W3O44(square markers) and PNb13W3O44(circle markers) with phosphorus on the tetrahedral positions at different C-rates corresponding to 1 Li per transition metal discharge in 20 hours (C / 20) to 3 mins (20 C). In the rate test, electrodes were cycled under the same conditions from 2.7 to 1.2 V at constant current12009062.8567. WO00\l 84663322.1PCT Application Attorney Docket No.: 009062.8567. WO00vs. Li metal counter electrodes. The following parameters were used in the test: C / 20 formation cycles included; 80:10:10 ratio of electrode active material to conductive carbon to polymer binder.

[0079] FIG. 23 shows example data obtained from a rate test of some disclosed materials. Specifically, FIG. 23 shows electrochemical capacity of Nb14W3O44(square markers) and PNb13W3O44(circle markers) with phosphorus on the tetrahedral positions at different C-rates corresponding to 1 Li per transition metal discharge in 20 hours (C / 20) to 3 mins (20 C). In the rate test, electrodes were cycled under the same conditions from 2.7 to 1.0 V at constant current vs. Li metal counter electrodes. The following parameters were used in the test: C / 20 formation cycles included; 80:10:10 ratio of electrode active material to conductive carbon to polymer binder.

[0080] FIG. 24 shows example data obtained from a rate test of some disclosed materials. Specifically, FIG. 24 shows electrochemical capacity of Nb12WO33(square markers) and PNb11WO333 (circle markers) with phosphorus on the tetrahedral positions at different C-rates corresponding to 1 Li per transition metal discharge in 20 hours (C / 20) to 3 mins (20 C). In the rate test, electrodes were cycled under the same conditions from 3.0 to 1.2 V at constant current vs. Li metal counter electrodes. The following parameters were used in the test: C / 20 formation cycles included; 80:10:10 ratio of electrode active material to conductive carbon to polymer binder.

[0081] FIG. 25 shows example data obtained from a rate test of some disclosed materials. Specifically, FIG. 25 shows electrochemical capacity of Nb12WO33(square markers) and PNb11WO33(circle markers) with phosphorus on the tetrahedral positions at different C-rates corresponding to 1 Li per transition metal discharge in 20 hours (C / 20) to 3 mins (20 C). In the rate test, electrodes were cycled under the same conditions from 2.7 to 1.0 V at constant current vs. Li metal counter electrodes. The following parameters were used in the test: C / 20 formation cycles included; 80:10:10 ratio of electrode active material to conductive carbon to polymer binder.

[0082] FIG. 26 shows example data obtained from a rate test of some disclosed materials. Specifically, FIG. 26 shows electrochemical capacity of Nb14W3O44(square markers) and PNb13W3O44(circle markers) with phosphorus on the tetrahedral positions at different C-rates13009062.8567. WO00\l 84663322.1PCT Application Attorney Docket No.: 009062.8567. WO00corresponding to 1 Li per transition metal discharge in 20 hours (C / 20) to 3 mins (20 C). In the rate test, electrodes were cycled under the same conditions from 3.0 to 1.0 V at constant current discharge and constant current constant voltage charge vs. Li metal counter electrodes. The following parameters were used in the test: C / 20 formation cycles included; 80:10:10 ratio of electrode active material to conductive carbon to polymer binder.

[0083] FIG. 27 shows example data obtained from a rate test of some disclosed materials. Specifically, FIG. 27 shows electrochemical capacity of Nb14W3O44(dark circles) and PNb13W3O44(light circles) with phosphorus on the tetrahedral positions at different C-rates corresponding to 1 Li per transition metal discharge in 10 hours (C / 20) to 3 mins (20 C).. In the rate test, electrodes were cycled under the same conditions from 2.7 to 1.0 V at constant current discharge and constant current constant voltage charge vs. Li metal counter electrodes. The following parameters were used in the test: C / 20 formation cycles done; 80: 10: 10 ratio of electrode active material to conductive carbon to polymer binder.

[0084] FIG. 28 shows example data obtained from a cycle test of some disclosed materials. Specifically, FIG. 28 shows electrochemical capacity of Nb12WO33and PNb12WO33with phosphorus on the tetrahedral positions at a C-rates corresponding to 1 Li per transition metal discharge in 6 mins (10 C). In the cycle test, electrodes were cycled under the same conditions from 3.0 to 1.0 V at constant current vs. Li metal counter electrodes. The following parameters were used in the test: 10C, no formation cycles, no check-up cycles; 80:10:10 ratio of electrode active material to conductive carbon to polymer binder.

[0085] FIG. 29 shows example data obtained from a cycle test of some disclosed materials. Specifically, FIG. 29 shows electrochemical capacity of Nb14W3O44and PNb13W3O33with phosphorus on the tetrahedral positions at a C-rates corresponding to 1 Li per transition metal discharge in 6 mins (10 C). In the cycle test, electrodes were cycled under the same conditions from 3.0 to 1.0 V at constant current vs. Li metal counter electrodes. The following parameters were used in the test: 10C, no formation cycles, no check-up cycles; 80:10:10 ratio of electrode active material to conductive carbon to polymer binder.

[0086] FIG. 30 shows example data obtained from a cycle test of some disclosed materials. Specifically, FIG. 30 shows electrochemical capacity of Nb12WO33and PNb11WO33with phosphorus on the tetrahedral positions at a C-rates corresponding to 1 Li per transition metal14009062.8567. WO00\l 84663322.1PCT Application Attorney Docket No.: 009062.8567. WO00discharge in 6 mins (10 C) with every 10th cycle being at C / 3. In the cycle test, electrodes were cycled under the same conditions from 3.0 to 1.0 V at constant current discharge and constant current constant voltage charge vs. Li metal counter electrodes. The following parameters were used in the test: 10C, no formation cycles, C / 3 check-up cycles; 80:10:10 ratio of electrode active material to conductive carbon to polymer binder.

[0087] FIG. 31 shows example data obtained from a cycle test of some disclosed materials. Specifically, FIG. 31 shows electrochemical capacity of Nb14W3O44(black) and PNb13W3O44(red) with phosphorus on the tetrahedral positions at a C-rates (current densities) corresponding to 1 Li per transition metal discharge in 6 mins (10 C) with every 10th cycle being at C / 3. In the cycle test, electrodes were cycled under the same conditions from 3.0 to 1.0 V at constant current discharge and constant current constant voltage charge vs. Li metal counter electrodes. The following parameters were used in the test: 10C, no formation cycles, C / 3 check-up cycles; 80:10:10 ratio of electrode active material to conductive carbon to polymer binder.

[0088] FIG. 32 shows example data obtained from a cycle test of some disclosed materials. Specifically, FIG. 32 shows electrochemical capacity of Nb14W3O44(black) and PNb13W3O44(red) with phosphorus on the tetrahedral positions at a C-rates (current densities) corresponding to 1 Li per transition metal discharge in 6 mins (10 C) with every 10th cycle being at C / 3. In the cycle test, electrodes were cycled under the same conditions from 2.7 to 1.2 V at constant current discharge and constant current constant voltage charge vs. Li metal counter electrodes. The following parameters were used in the test: 10C, no formation cycles, C / 3 check-up cycles; 80:10:10 ratio of electrode active material to conductive carbon to polymer binder.

[0089] FIG. 33 shows example data obtained from a cycle test of some disclosed materials. Specifically, FIG. 33 shows electrochemical capacity of Nb14W3O44Tu (black) and PNb13W3O44(red) with phosphorus on the tetrahedral positions at a C-rates (current densities) corresponding to 1 Li per transition metal discharge in 6 mins (10 C) with every 10th cycle being at C / 3. In the cycle test, electrodes were cycled under the same conditions from 2.7 to 1.0 V at constant current discharge and constant current constant voltage charge vs. Li metal counter electrodes. The following parameters were used in the test: 10C, no formation cycles, C / 3 check-up cycles; 80:10:10 ratio of electrode active material to conductive carbon to polymer binder.

[0090] Example P-tetrahedra Nuclear Magnetic Resonance (NMR) and X-ray15009062.8567. WO00\l 84663322.1PCT Application Attorney Docket No.: 009062.8567. WO00Diffraction (XRD) Data of Some Disclosed Materials

[0091] The structure of materials disclosed in the present patent document can be characterized by various techniques. For example,31P NMR is one way to detect tetrahedral phosphorus. As will be explained in further detail to follow, in some example characterizations of disclosed materials, NMR is complemented by XRD to demonstrate the overall structure of the material. In some characterizations, certain XRD peaks are extremely sensitive to the phosphorus content of the material, particularly those at small diffraction angles, i.e., at small 26 angles, i.e. at large d-spacings. In some cases, there is a small shift in peak positions (to higher angles) and lattice parameters (to smaller values) when phosphorus is incorporated. In some cases, such behavior is because phosphorus is smaller than niobium.

[0092] FIG. 34 shows a31P NMR spectrum of a disclosed PNb11WO33material referenced to 85% H3PO4(aq.). The spectrum was measured at 10 kHz magic-angle spinning (MAS) rate and 9.4 T magnetic field on powder in a 5-mm-diameter rotor. 109 scans were recorded with a recycle delay of 2000 seconds.

[0093] FIG. 35 shows a31P NMR spectrum of a disclosed PNb13W3O44material referenced to 85% HsPO4(aq.). The spectrum was measured at 10 kHz magic-angle spinning (MAS) rate and 9.4 T magnetic field on powder in a 5-mm-diameter rotor. 24 scans were recorded with a recycle delay of 2000 seconds.

[0094] FIG. 36 shows example XRD data (Cu Ka radiation) of some disclosed materials. Specifically, FIG. 36 shows XRD patterns of niobium and mixed-metal niobium containing oxides, based on the disclosed technology, without phosphorus (solid line) and with phosphorus (dotted line) on the tetrahedral sites. FIG. 36 shows example XRD patterns (a)-(j) for the following disclosed materials: (a) Nb280?o, i.e., H-Nb2O5, (b) PNb27O70, (c) Nb12WO33. (d) PNb11WO33, (e) Nb16W5O55, (f) PNb15W5O55, (g) Nb14W3O44, (h) PNb13W3O44, (i) TiNb24O62, (j) PTiNb23O62.

[0095] FIG. 37 shows example XRD data of the disclosed materials PNb11WO333 (top spectrum in FIG. 37) and Nb12WO33(middle spectrum in FIG. 37). FIG. 37 also shows a model spectrum of Nb12WO33(bottom spectrum in FIG. 37).

[0096] FIG. 38 shows example XRD data of the disclosed materials PNb13W3O44(top spectrum in FIG. 38) and Nb14W3O44(middle spectrum in FIG. 38). FIG. 46 also shows a model spectrum of Nb14W3O44(bottom spectrum in FIG. 38).16009062.8567. WO00\l 84663322.1PCT Application Attorney Docket No.: 009062.8567. WO00

[0097] FIG. 39 shows example XRD data of the disclosed materials PNb15W5O55(top spectrum in FIG. 39) and Nb16W5O55(middle spectrum in FIG. 39). FIG. 39 also shows a model spectrum of Nb16W5O55(bottom spectrum in FIG. 39).

[0098] FIG. 40 shows example XRD data of the disclosed materials PNb17W8O69(top spectrum in FIG. 40) and Nb18W8O69(middle spectrum in FIG. 40). FIG. 40 also shows a model spectrum of Nb18W8O69(bottom spectrum in FIG. 48).

[0099] FIG. 41 shows example31P NMR data of the disclosed material PNb11WO333. FIG. 41 shows incorporation of phosphorus into the niobium-based complex oxide.

[0100] FIG. 42 shows example31P NMR data of the disclosed material PNb13W3O44. FIG. 42 shows incorporation of phosphorus into the niobium-based complex oxide.

[0101] Example Crystal Structure of Some Disclosed Materials

[0102] FIGS. 43-47 show example crystal structures of some materials based on the disclosed technology. In FIGS. 43-47, circles represent tetrahedral columns or sites on which one or more redox-inactive cations may be located in accordance with some disclosed embodiments. More specifically, in some disclosed embodiments, material compositions that have reducible (redoxactive) cations are replaced with irreducible (redox-inactive) cations. In some implementations, the redox inactive cation is phosphorus. In some implementations, the reducible (redox- active) cations are located on tetrahedral columns or sites. Some disclosed embodiments are agnostic to the polyhedra in a crystal structure that connect to form blocks, separated by tetrahedra or tetrahedral columns. Some disclosed embodiments are agnostic to the size or ordering of the blocks.

[0103] FIG. 43 shows an example 1-4 body-centered tetragonal crystal structure of 7Nb2O5-3WC>3 according to an embodiment of the disclosed technology.

[0104] FIG. 44 shows an example P2-m crystal structure of Nb2O5-H according to an embodiment of the disclosed technology.

[0105] FIG. 45 shows an example C2 crystal structure of 6Nb2O5-WO3according to an embodiment of the disclosed technology.

[0106] FIG. 46 shows an example C2 crystal structure of 8Nb205-5WC>3 according to an embodiment of the disclosed technology.17009062.8567. WO00\l 84663322.1PCT Application Attorney Docket No.: 009062.8567. WO00

[0107] FIG. 47 shows an example C2 crystal structure of TiNb24O62according to an embodiment of the disclosed technology.

[0108] FIG. 48 shows a flow chart of an example method 400 of producing an active electrode material for an energy storage device. At step 410, the method 400 comprises providing a niobium-based oxide having a crystal structure comprising one or more tetrahedral sites. In some implementations, the crystal structure includes a reducible cation at each of the one or more tetrahedral sites. At step 420, the method 400 comprises replacing the reducible cation, at each of the one or more sites, with an irreducible cation comprising phosphorus. In some implementations, the replacing of the reducible cation modifies one or more parameters of the energy storage device. In some implementations, the one or more parameters relate to a charge storage capacity of the energy storage device.

[0109] Embodiments of the disclosed technology support inter alia the following examples.

[0110] Example 1. An active electrode material of a battery device, comprising: a metal oxide comprising niobium (Nb); and a plurality of redox-inactive cations comprising phosphorus (P), wherein: the metal oxide has a crystal structure comprising one or more tetrahedral sites, some or all of the one or more tetrahedral sites are occupied by a respective redox-inactive cation, and the active electrode material has a niobium-to-phosphorus element ratio (Nb: P) greater than 9:1.

[0111] Example 2. The active electrode material of example 1, wherein the crystal structure is a Wadsley — Roth crystal structure.

[0112] Example 3. The active electrode material of example 1, wherein the metal oxide comprises an additional metallic element.

[0113] Example 4. The active electrode material of example 3. wherein the additional metallic element is Ti or W.

[0114] Example 5. The active electrode material of example 1, wherein the active electrode material has a chemical formula PNb27O70. PNbnWC>33, PNb13W3O44. PNb15W5O55, PNb17W8O69, PTiNb23O62, PNb21O54, PNb24O62, or PNb46O116.

[0115] Example 6. The active electrode material of example 5, wherein a metallic element in any one of PNb27O70, PNb11WO333, PNb13W3O44, PNb15W5O55, PNb17W8O69e, PTiNb23O62, PNb21O54, PNb24C>62, or PNb46O116is substituted with an element having a same charge as the metallic element.18009062.8567. WO00\l 84663322.1PCT Application Attorney Docket No.: 009062.8567. WO00

[0116] Example 7. The active electrode material of example 5, wherein a metallic element in any one of PNb27O70, PNbiiWC>33, PNb13W3O44, PNb15W5O55, PNb17W8O69i, PTiNb23O62, PNb21O54, PNb24O62, or PNb46O116is substituted with an element having a charge that is different from that of the metallic element.

[0117] Example 8. The active electrode material of any one of examples 1-7, wherein the active electrode material is coated with carbon.

[0118] Example 9. The active electrode material of any one of examples 1-8, wherein the active electrode material comprises one or more dopants.

[0119] Example 10. The active electrode material of any one of examples 1-9, wherein the active electrode material is produced from at least two precursor materials, wherein the at least two precursor materials include a first precursor material comprising Nb and a second precursor material comprising P.

[0120] Example 11. The active electrode material of example 10, wherein the first precursor material is niobium oxide (Nb2O5), hydrous Nb2O5·nH2O where n = 0-10, ammonium niobium oxalate NH4NbO(C2O4)2(H2O)2·nH2O where n = 0-10, or ammonium phosphate monobasic.

[0121] Example 12. The active electrode material of example 11, wherein the first precursor material is niobium oxide with a D50 particle size <10 pm.

[0122] Example 13. The active electrode material of example 11, wherein the first precursor material is niobium oxide with a D50 particle size < 5 pm or between 0.25 and 5 pm.

[0123] Example 14. The active electrode material of any one of examples 1-9, wherein the active electrode material is produced from a reaction of a first precursor material with a material comprising phosphorus, wherein the reaction occurs at a temperature between 800-1500 degrees Celsius.

[0124] Example 15. The active electrode material of example 14, wherein the first precursor material is a mixed niobium-phosphorus precursor selected from NbOPO4or niobium phosphate hydrate NbOPO4·nH2O where n = 0-10.

[0125] Example 16. An energy storage device, comprising: an anode; a cathode; and an electrolyte coupling the cathode to the anode, wherein the anode comprises an active electrode material as recited in any one of examples 1-15.

[0126] Example 17. The energy storage device of example 16, wherein the cathode comprises Li and at least one of Ni, Mn, Co, Al, Fe, P or a combination thereof.19009062.8567. WO00\l 84663322.1PCT Application Attorney Docket No.: 009062.8567. WO00

[0127] Example 18. The energy storage device of example 16, wherein the cathode comprises Li and a disordered rocksalt material (DRX).

[0128] Example 19. The energy storage device of any one of examples 16-18, wherein the plurality of redox-inactive cations are irreducible during an operation of the energy storage device.

[0129] Example 20. The energy storage device of any one of examples 16-18, wherein the energy storage device is a Li-ion battery.

[0130] Example 21. A method of producing an active electrode material for an energy storage device, comprising: providing a niobium-based oxide having a crystal structure comprising one or more tetrahedral sites, wherein the crystal structure includes a reducible cation at each of the one or more tetrahedral sites; and replacing the reducible cation, at some or all of the one or more tetrahedral sites, with an irreducible cation comprising phosphorus, wherein the replacing of the reducible cation modifies one or more parameters of the energy storage device, wherein the one or more parameters relate to a charge storage capacity of the energy storage device.

[0131] Example 22. The method of example 21, wherein the niobium-based oxide has a chemical formula Nb2O5, Nb12WO33, Nb14W3O44, Nb16W5O55, Nb18W8O69, TiNb24O62.

[0132] Example 23. A method of modifying a material composition, comprising: adding an irreducible cation to a crystal structure of the material composition, wherein the irreducible cation is added to the crystal structure at a predetermined position on the crystal structure, wherein the adding of the irreducible cation modifies one or more parameters of the crystal structure.

[0133] Example 24. The method of example 23, wherein the irreducible cation is phosphorus and the predetermined positioned is a tetrahedral position on the crystal structure.

[0134] Example 25. The method of example 23, wherein the irreducible cation replaces a reducible cation included in the material composition before the modifying.

[0135] Example 26. The method of example 23, wherein the material composition after the modifying is implemented in an energy storage device.

[0136] Example 27. The method of example 26, wherein the adding of the irreducible cation increases charge storage capacity of the energy storage device.

[0137] Example 28. The method of example 26, wherein the energy storage device comprises an anode, wherein the anode comprises the material composition after the modifying.

[0138] Example 29. The method of example 27, wherein the energy storage device is a lithium-ion battery.20009062.8567. WO00\l 84663322.1PCT Application Attorney Docket No.: 009062.8567. WO00

[0139] Example 30. The method of example 23, wherein the one or more parameters include one or more of stability or reversibility.

[0140] Example 31. The method of example 23. wherein the material composition after the modifying comprises PNbivCho, PNb12WO33, PNb13W3O44k, PNb15W5O55, PNb17W8O69, PTiNbz^Oca.

[0141] Example 32. The method of any previous examples earned out using a device comprising a processor and a memory comprising processor executable code that upon execution by the processor causes the operations to be performed.

[0142] Implementations of the subject matter and the functional operations described in this patent document can be implemented in various systems, digital electronic circuitry, or in computer software, firmware, or hardware, including the structures disclosed in this specification and their structural equivalents, or in combinations of one or more of them. Implementations of the subject matter described in this specification can be implemented as one or more computer program products, i.e., one or more modules of computer program instructions encoded on a tangible and non-transitory computer readable medium for execution by, or to control the operation of, data processing apparatus. The computer readable medium can be a machine-readable storage device, a machine-readable storage substrate, a memory device, a composition of matter effecting a machine -readable propagated signal, or a combination of one or more of them. The term “data processing unit” or “data processing apparatus” encompasses all apparatus, devices, and machines for processing data, including by way of example a programmable processor, a computer, or multiple processors or computers. The apparatus can include, in addition to hardware, code that creates an execution environment for the computer program in question, e.g., code that constitutes processor firmware, a protocol stack, a database management system, an operating system, or a combination of one or more of them.

[0143] A computer program (also known as a program, software, software application, script, or code) can be written in any form of programming language, including compiled or interpreted languages, and it can be deployed in any form, including as a stand-alone program or as a module, component, subroutine, or other unit suitable for use in a computing environment. A computer program does not necessarily correspond to a file in a file system. A program can be stored in a portion of a file that holds other programs or data (e.g., one or more scripts stored in a markup language document), in a single file dedicated to the program in question, or in multiple21009062.8567. WO00\l 84663322.1PCT Application Attorney Docket No.: 009062.8567. WO00coordinated files (e.g., files that store one or more modules, sub programs, or portions of code). A computer program can be deployed to be executed on one computer or on multiple computers that are located at one site or distributed across multiple sites and interconnected by a communication network.

[0144] The processes and logic flows described in this specification can be performed by one or more programmable processors executing one or more computer programs to perform functions by operating on input data and generating output. The processes and logic flows can also be performed by, and apparatus can also be implemented as, special purpose logic circuitry, e.g., an FPGA (field programmable gate array) or an ASIC (application specific integrated circuit).

[0145] Processors suitable for the execution of a computer program include, by way of example, both general and special purpose microprocessors, and any one or more processors of any kind of digital computer. Generally, a processor will receive instructions and data from a read only memory or a random access memory or both. The essential elements of a computer are a processor for performing instructions and one or more memory devices for storing instructions and data. Generally, a computer will also include, or be operatively coupled to receive data from or transfer data to, or both, one or more mass storage devices for storing data, e.g., magnetic, magneto optical disks, or optical disks. However, a computer need not have such devices. Computer readable media suitable for storing computer program instructions and data include all forms of nonvolatile memory, media and memory devices, including by way of example semiconductor memory devices, e.g., EPROM, EEPROM, and flash memory devices. The processor and the memory can be supplemented by, or incorporated in, special purpose logic circuitry.

[0146] While this patent document contains many specifics, these should not be construed as limitations on the scope of any invention or of what may be claimed, but rather as descriptions of features that may be specific to particular embodiments of particular inventions. Certain features that are described in this patent document in the context of separate embodiments can also be implemented in combination in a single embodiment. Conversely, various features that are described in the context of a single embodiment can also be implemented in multiple embodiments separately or in any suitable subcombination. Moreover, although features may be described above as acting in certain combinations and even initially claimed as such, one or more features from a claimed combination can in some cases be excised from the combination, and the claimed combination may be directed to a subcombination or variation of a subcombination.22009062.8567. WO00\l 84663322.1PCT Application Attorney Docket No.: 009062.8567. WO00

[0147] Similarly, while operations are depicted in the drawings in a particular order, this should not be understood as requiring that such operations be performed in the particular order shown or in sequential order, or that all illustrated operations be performed, to achieve desirable results. Moreover, the separation of various system components in the embodiments described in this patent document should not be understood as requiring such separation in all embodiments.

[0148] Section headings are used in the present document only for ease of understanding and do not limit scope of the embodiments to the section in which they are described.

[0149] Only a few implementations and examples are described and other implementations, enhancements and variations can be made based on what is described and illustrated in this patent document.23009062.8567. WO00\l 84663322.1

Claims

PCT Application Attorney Docket No.: 009062.8567. WO00CLAIMSWhat is claimed is:

1. An active electrode material of a battery device, comprising:a metal oxide comprising niobium (Nb); anda plurality of redox-inactive cations comprising phosphorus (P), wherein:the metal oxide has a crystal structure comprising one or more tetrahedral sites, some or all of the one or more tetrahedral sites are occupied by a respective redox-inactive cation, andthe active electrode material has a niobium-to-phosphorus element ratio (Nb: P) greater than 9:1.

2. The active electrode material of claim 1, wherein the crystal structure is a Wadsley-Roth crystal structure.

3. The active electrode material of claim 1, wherein the metal oxide comprises an additional metallic element.

4. The active electrode material of claim 3, wherein the additional metallic element is Ti or W.

5. The active electrode material of claim 1, wherein the active electrode material has a chemical formula PNbivOvo, PNbnWC>33, PNbisWsCM, PNbisWsCLs, PNb17W8O69, PTiNb23C>62, PNb2iOs4, PNb24C>62, or PNb46O116.

6. The active electrode material of claim 5, wherein a metallic element in any one of PNb27O70, PNb11WO333, PNbi3W3C>44, PNb15W5O55, PNb17W8O69e, PTiNb23O62, PNb2iOs4, PNb24C>62, or PNb460iieis substituted with an element having a same charge as the metallic element.

7. The active electrode material of claim 5, wherein a metallic element in any one of PNb2?07o, PNb11WO33, PNb13W3O44, PNb15W5O55, PNb17W8O69s, PTiNb23O62, PNb2iOs4, PNb24O62, or PNb460ii6 is substituted with an element having a charge that is different from that of the metallic element.24009062.8567. WO00\l 84663322.1PCT Application Attorney Docket No.: 009062.8567. WO008. The active electrode material of any one of claims 1-7, wherein the active electrode material is coated with carbon.

9. The active electrode material of any one of claims 1-8, wherein the active electrode material comprises one or more dopants.

10. The active electrode material of any one of claims 1-9, wherein the active electrode material is produced from at least two precursor materials, wherein the at least two precursor materials include a first precursor material comprising Nb and a second precursor material comprising P.

11. The active electrode material of claim 10, wherein the first precursor material is niobium oxide (Nb2O5), hydrous Nb2C>5-«H2O where n = 0-10, ammonium niobium oxalate NH4NbO(C2O4)2(H2O)2·nH2O where n = 0-10, or ammonium phosphate monobasic.

12. The active electrode material of claim 11, wherein the first precursor material is niobium oxide with a D50 particle size <10 pm.

13. The active electrode material of claim 11, wherein the first precursor material is niobium oxide with a D50 particle size < 5 pm or between 0.25 and 5 pm.

14. The active electrode material of any one of claims 1-9, wherein the active electrode material is produced from a reaction of a first precursor material with a material comprising phosphorus, wherein the reaction occurs at a temperature between 800-1500 degrees Celsius.

15. The active electrode material of claim 14, wherein the first precursor material is a mixed niobium-phosphorus precursor selected from NbOPCU or niobium phosphate hydrate NbOPO4·nH2O where n = 0–10.

16. An energy storage device, comprising:an anode;a cathode; andan electrolyte coupling the cathode to the anode, wherein the anode comprises an active electrode material as recited in any one of claims 1-15.25009062.8567. WO00\l 84663322.1PCT Application Attorney Docket No.: 009062.8567. WO0017. The energy storage device of claim 16, wherein the cathode comprises Li and at least one of Ni, Mn, Co, Al, Fe, P or a combination thereof.

18. The energy storage device of claim 16, wherein the cathode comprises Li and a disordered rocksalt material (DRX).

19. The energy storage device of any one of claims 16-18, wherein the plurality of redox-inactive cations are irreducible during an operation of the energy storage device.

20. The energy storage device of any one of claims 16-18, wherein the energy storage device is a Li-ion battery.

21. A method of producing an active electrode material for an energy storage device, comprising:providing a niobium-based oxide having a crystal structure comprising one or more tetrahedral sites, wherein the crystal structure includes a reducible cation at each of the one or more tetrahedral sites; andreplacing the reducible cation, at some or all of the one or more tetrahedral sites, with an irreducible cation comprising phosphorus,wherein the replacing of the reducible cation modifies one or more parameters of the energy storage device,wherein the one or more parameters relate to a charge storage capacity of the energy storage device.

22. The method of claim 21, wherein the niobium-based oxide has a chemical formula Nb2O.s, Nb12WO33, Nbi4W3O44, Nb16W5O55, Nb18W8O69, TiNb24C>62.26009062.8567. WO00\l 84663322.1

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