Vehicle battery

Abstract

A battery cell for an electric vehicle, a battery module, a battery pack, a vehicle, battery cells, and a method of providing a battery cell are disclosed. The battery cell for the electric vehicle comprises 10-40 wt% lithium titanium oxide; 0.1-30 wt% graphite; and 0.1-25 wt% graphene.

Description

[0001] Vehicle Battery

[0002] FIELD OF THE INVENTION

[0003] This invention relates to the field of battery cells for vehicles. In particular, this invention relates to battery compositions, shapes of battery cells for vehicles, and battery modules and battery packs for vehicles. Some examples of the invention may also relate to battery cells for other purposes.

[0004] BACKGROUND TO THE INVENTION

[0005] There is a desire to move away from the use of combustion engines in vehicles and to move towards electric vehicles powered by modules of battery cells. Generally vehicle batteries are lithium-ion batteries.

[0006] In recent years there has, however, been reports of fires in electric vehicles. These may be caused by damage to one of the cells in the battery pack of the electric vehicle. Lithium-ion batteries may also present a fire risk if they are over-charged, short-circuited or are exposed to water.

[0007] A further disadvantage of lithium-ion batteries is the time taken to charge them. While fast electric vehicle chargers are available, and numbers of these fast chargers are on the rise, the time taken to charge an electric vehicle battery remains significantly longer than the time it takes to refuel a traditional petrol or diesel vehicle.

[0008] It is an aim of the present invention to overcome a disadvantage of current electric vehicle battery technology, whether referred to herein or otherwise.

[0009] SUMMARY OF THE INVENTION

[0010] A first aspect of the invention provides a battery cell for an electric vehicle comprising:

[0011] 10-40 wt% lithium titanium oxide;0.1-30 wt% graphite; and

[0012] 0.1-25 wt% graphene.

[0013] The battery cell may comprise 5-25 wt% graphene.

[0014] The battery cell may comprise 5-12 wt% graphene.

[0015] The 0.1-25 wt% graphene may instead be 5-25 wt% graphene.

[0016] The battery cell may comprise 0.2-25 wt% graphene, or 0.3-25 wt% graphene, or 0.4-25 wt% graphene, or 0.5-25 wt% graphene, or 0.6-25 wt% graphene, or 0.7-25 wt% graphene, or 0.8-25 wt% graphene, or 0.9-25 wt% graphene, or 1-25 wt% graphene, or 2-25 wt% graphene, or 3-25 wt% graphene, or 4-25 wt% graphene, 5-25 wt% graphene, or 6-25 wt% graphene, or 7-25 wt% graphene, or 8-25 wt% graphene, or 9-25 wt% graphene, or 10-25 wt% graphene, or 15-25 wt% graphene, or 20-25 wt% graphene.

[0017] The battery cell may comprise 0.1-20 wt% graphene, or 0.1-15 wt% graphene, or 0.1-10 wt% graphene, or 0.1-5 wt% graphene, or 0.1-1 wt% graphene. The battery cell may comprise 1-5 wt% graphene, or 1-10 wt graphene, or 1-20 wt% graphene, or 1-25 wt% graphene. The battery cell may comprise 5-10 wt% graphene, or 5-15 wt% graphene, or 5-20 wt% graphene.

[0018] The battery cell may comprise 0.2-30 wt% graphite, or 0.3-30 wt% graphite, or 0.4-30 wt% graphite, or 0.5-30 wt% graphite, or 0.6-30 wt% graphite, or 0.7-30 wt% graphite, or 0.8-30 wt% graphite, or 0.9-30 wt% graphite, or 1-30 wt% graphite, or 2-30 wt% graphite, or 3-30 wt% graphite, or 4-30 wt% graphite, 5-30 wt% graphite, or 6-30 wt% graphite, or 7-30 wt% graphite, or 8-30 wt% graphite, or 9-30 wt% graphite, or 10-30 wt% graphite, or 15-30 wt% graphite, or 20-30 wt% graphite, or 25-30 wt% graphite.

[0019] The battery cell may comprise 0.1-25 wt% graphite, 0.1-20 wt% graphite, or 0.1-15 wt% graphite, or 0.1-10 wt% graphite, or 0.1-5 wt% graphite, or 0.1-1 wt% graphite.The battery cell may comprise 1-5 wt% graphite, or 1-10 wt graphite, or 1-20 wt% graphite, or 1-25 wt% graphite, or 1-30 wt% graphite. The battery cell may comprise 5-10 wt% graphite, or 5-15 wt% graphite, or 5-20 wt% graphite, or 5-30 wt% graphite.

[0020] The battery cell may comprise 0.1 and 10 wt% graphite. The battery cell may comprise or 0.2-10 wt% graphite, or 0.3-10 wt% graphite, or 0.4-10 wt% graphite, or 0.5-10 wt% graphite, or 0.6-10 wt% graphite, or 0.7-10 wt% graphite, or 0.8-10 wt% graphite, or 0.9-10 wt% graphite, or 1-10 wt% graphite, or 2-10 wt% graphite, or 3-10 wt% graphite, or 4-10 wt% graphite, 5-10 wt% graphite, or 6-10 wt% graphite, or 7-10 wt% graphite, or 8-10 wt% graphite, or 9-10 wt% graphite.

[0021] The battery cell may comprise 15-40 wt% lithium titanium oxide, or 20-40 wt% lithium titanium oxide, or 25-40 wt% lithium titanium oxide, or 30-40 wt% lithium titanium oxide, or 35-40 wt% lithium titanium oxide.

[0022] The battery cell may comprise 10-35 wt% lithium titanium oxide, or 10-30 wt% lithium titanium oxide, or 10-25 wt% lithium titanium oxide, or 10-20 wt% lithium titanium oxide, or 10-15 wt% lithium titanium oxide.

[0023] The battery cell may comprise 15-30 wt% lithium titanium oxide.

[0024] The graphite may in the form of activated graphite. The graphene may be in the form of propylene graphene.

[0025] In some embodiments the battery cell comprises:

[0026] 15-30 wt% lithium titanium oxide;

[0027] 0.1-20 wt% activated graphite; and

[0028] 0.1-20 wt% propylene graphene.

[0029] The battery cell may comprise 10-20 wt% activated graphite. The battery cell may comprise 0.1-10 wt% activated graphite.The battery cell may comprise 1-20 wt% propylene graphene. The battery cell may comprise 10-20 wt% propylene graphene.

[0030] In other embodiments the battery cell comprises:

[0031] 15-30 wt% lithium titanium oxide;

[0032] 0.1-15 wt% activated graphite;

[0033] 0.1-20 wt% propylene graphene; and

[0034] 0.1-15 wt% biochar.

[0035] The battery cell may comprise 0.1-10 wt% activated graphite.

[0036] The battery cell may comprise 1-20 wt% propylene graphene. The battery cell may comprise 10-20 wt% propylene graphene.

[0037] The battery cell may further comprises Phosphate(l-), Hexafluoro-, Lithium; aluminium; cobalt; manganese; chromium; acetonitrile and tetraethylammonium tetrafluoroborate.

[0038] In some preferred embodiments the battery cell comprises:

[0039] 15-30 wt% lithium titanium oxide;

[0040] 0.1-20 wt% activated graphite;

[0041] 0.1-20 wt% propylene graphene;

[0042] 1-3 wt% Phosphate(l-), Hexafluoro-, Lithium

[0043] 3-7 wt% aluminium;

[0044] 7-13 wt% cobalt;

[0045] 5-10 wt% manganese;

[0046] 5-15 wt% acetonitrile; and

[0047] 1-5 wt% tetraethylammonium tetrafluoroborate.

[0048] The battery cell may comprise 10-20 wt% activated graphite. The battery cell may comprise 1-20 wt% activated graphite. The battery cell may comprise 0.1-10 wt% activated graphite.The battery cell may comprise 1-20 wt% propylene graphene. The battery cell may comprise 10-20 wt% propylene graphene. The battery cell may comprise 0.1-10 wt% propylene graphene.

[0049] The battery cell may comprise <0.01 wt% chromium. The battery cell may comprise 0-5 wt% chromium. The battery cell may comprise 0.01-5 wt% chromium, for example 0.1-5 wt% chromium.

[0050] In other preferred embodiments the battery cell comprises:

[0051] 15-30 wt% lithium titanium oxide;

[0052] 0.1-15 wt% activated graphite;

[0053] 0.1-20 wt% propylene graphene;

[0054] 0.1-15 wt% biochar;

[0055] 1-3 wt% Phosphate(l-), Hexafluoro-, Lithium

[0056] 3-7 wt% aluminium;

[0057] 7-13 wt% cobalt;

[0058] 5-10 wt% manganese;

[0059] 5-15 wt% acetonitrile; and

[0060] 1-5 wt% tetraethylammonium tetrafluoroborate.

[0061] The battery cell may comprise 10-20 wt% activated graphite. The battery cell may comprise 0.1-10 wt% activated graphite.

[0062] The battery cell may comprise 1-20 wt% propylene graphene. The battery cell may comprise 10-20 wt% propylene graphene.

[0063] The battery cell may comprise <0.01 wt% chromium. The battery call may comprise 0-5 wt% chromium. The battery cell may comprise 0.01-5 wt% chromium, for example 0.1-5 wt% chromium.

[0064] In preferred embodiment a physical external shape of the battery cell allows for close packing of the cells in a battery module or battery pack. The physical external shape of the battery cell may be in the form of a hexagonal prism.A second aspect of the invention provides a battery module comprising a plurality of battery cells, each battery cell being according to the first aspect of the invention. In preferred embodiments each battery cell in the battery module is in contact with all neighbouring battery cells. In embodiments in which the physical external shape of the battery cell is in the form of a hexagonal prism, the battery cells are preferably arranged in a hexagonal or honeycomb array.

[0065] A third aspect of the invention provides a battery pack comprising two or more battery modules, each battery module being according to the second aspect of the invention.

[0066] A fourth aspect of the invention provides a vehicle including a battery pack according to the third aspect of the invention.

[0067] A fifth aspect of the invention provides a battery cell, comprising:

[0068] 10-40 wt% lithium titanium oxide;

[0069] 1-5 wt% phosphate (1-), hexafluoro-, lithium;

[0070] 1-30 wt% activated carbon;

[0071] 1-10 wt% aluminium;

[0072] 1 -20 wt% cobalt;

[0073] 1-20 wt% manganese;

[0074] 1 -30 wt% propylene carbonate;

[0075] 1-20 wt% acetonitrile; and

[0076] 1-10 wt% tetraethylammonium tetrafluoroborate.

[0077] The battery cell may comprise 15-30 wt% lithium titanium oxide. The battery cell may comprise 1-3 wt% phosphate (1-), hexafluoro-, lithium. The battery cell may comprise 10-20 wt% activated carbon. The battery cell may comprise 3-7 wt% aluminium. The battery cell may comprise 7-13 wt% cobalt. The battery cell may comprise 5-10 wt% manganese. The battery cell may comprise 1-20 wt% propylene carbonate. The battery cell may comprise 10-20 wt% propylene carbonate. The battery cell may comprise 1-5 wt% acetonitrile. The battery cell may comprise 1-5wt% tetraethylammonium tetrafluoroborate.

[0078] The battery cell may comprise 0.1-20 wt% activated graphite. The battery cell may comprise 0.1-10 wt% activated graphite.

[0079] The battery cell may comprise 0.1-10 wt% chromium. The battery cell may comprise 0.1-5 wt% chromium. The battery cell may comprise <0.01 wt% chromium.

[0080] The battery cell may comprise 0.1 -30 wt% propylene graphene. The battery cell may comprise 0.1-20 wt% propylene graphene.

[0081] The battery cell may comprise 0.1-20 wt% biochar. The battery cell may comprise 0.1-10 wt% biochar.

[0082] A positive electrode of the battery cell may comprise one or more of:

[0083] lithium titanium oxide;

[0084] phosphate (1-), hexafluoro- lithium;

[0085] activated graphite;

[0086] activated carbon;

[0087] aluminium;

[0088] cobalt;

[0089] manganese;

[0090] chromium;

[0091] propylene carbonate;

[0092] propylene graphene;

[0093] acetonitrile;

[0094] tetraethylammonium tetrafluoroborate; and / or

[0095] biochar.

[0096] A negative electrode of the battery cell may comprise one or more of:

[0097] lithium titanium oxide;

[0098] phosphate (1-), hexafluoro- lithium;

[0099] activated graphite;activated carbon;

[0100] aluminium;

[0101] cobalt;

[0102] manganese;

[0103] chromium;

[0104] propylene carbonate;

[0105] propylene graphene;

[0106] acetonitrile;

[0107] tetraethylammonium tetrafluoroborate; and / or

[0108] biochar.

[0109] An electrolyte of the battery cell may comprise one or more of:

[0110] lithium titanium oxide;

[0111] phosphate (1-), hexafluoro- lithium;

[0112] activated graphite;

[0113] activated carbon;

[0114] aluminium;

[0115] cobalt;

[0116] manganese;

[0117] chromium;

[0118] propylene carbonate;

[0119] propylene graphene;

[0120] acetonitrile;

[0121] tetraethylammonium tetrafluoroborate; and / or

[0122] biochar.

[0123] An inner surface portion of a container of the battery cell in contact with an electrolyte may comprise a graphite coating, the graphite coating optionally comprising activated graphite.

[0124] The battery cell may comprise lithium titanate. The lithium titanate may be disposed in the negative electrode. The battery cell may comprise lithium cobalt oxide and / or lithium manganese oxide. The lithium cobalt oxide and / or lithium manganese oxidemay be disposed in the negative electrode.

[0125] The battery cell may comprise at least one layer of positive electrode and at least one layer of negative electrode spaced apart by a separator. The separator may comprise a porous and / or ion permeable material. A further separator may be disposed on a respective remaining surface of the positive electrode and / or the negative electrode.

[0126] The positive electrode, the separator and the negative electrode are disposed in a layered manner in the battery cell, The positive electrode, the separator and the negative electrode may be disposed in a chamber of the battery cell. The electrolyte may be disposed in the chamber. The chamber may include a graphite coating on at least a portion of an internal surface of the chamber.

[0127] The positive electrode, negative electrode and separator may be spirally wound. The positive electrode, negative electrode and separator may be in the form of spirally wound sheets. The electrodes and separator (s) are disposed in a jelly roll or Swiss roll type structure.

[0128] The positive electrode, negative electrode and separator may be disposed as sheets arranged in a layered manner. The battery cell may be a pouch type battery cell.

[0129] A sixth aspect of the invention provides a battery cell, comprising:

[0130] at least one positive electrode portion comprising activated carbon; at least one negative electrode portion comprising lithium titanate and / or lithium titanium oxide; and

[0131] electrolyte comprising lithium hexafluorophosphate.

[0132] The at least one positive electrode portion may comprise lithium cobalt oxide and / or lithium manganese oxide.

[0133] The battery cell may further comprise one or more of:

[0134] 10-40 wt% lithium titanium oxide;1-5 wt% phosphate (1-), hexafluoro-, lithium;

[0135] 1-30 wt% activated carbon;

[0136] 1-10 wt% aluminium;

[0137] 1 -20 wt% cobalt;

[0138] 1-20 wt% manganese;

[0139] 1 -30 wt% propylene carbonate;

[0140] 1-20 wt% acetonitrile; and

[0141] 1-10 wt% tetraethylammonium tetrafluoroborate.

[0142] The battery cell may comprise 15-30 wt% lithium titanium oxide. The battery cell may comprise 1-3 wt% phosphate (1-), hexafluoro-, lithium. The battery cell may comprise 10-20 wt% activated carbon. The battery cell may comprise 3-7 wt% aluminium. The battery cell may comprise 7-13 wt% cobalt. The battery cell may comprise 5-10 wt% manganese. The battery cell may comprise 1-20 wt% propylene carbonate. The battery cell may comprise 10-20 wt% propylene carbonate. The battery cell may comprise 1-5 wt% acetonitrile. The battery cell may comprise 1-5 wt% tetraethylammonium tetrafluoroborate.

[0143] The battery cell may further comprise one or more of:

[0144] 0.1-20 wt% activated graphite;

[0145] 0.1-10 wt% chromium;

[0146] 0.1-30 wt% propylene graphene; and / or

[0147] 0.1-20 wt% biochar.

[0148] The battery cell may comprise 0.1-20 wt% activated graphite. The battery cell may comprise 0.1-10 wt% activated graphite. The battery cell may comprise 0.1-10 wt% chromium. The battery cell may comprise 0.1-5 wt% chromium. The battery cell may comprise <0.01 wt% chromium. The battery cell may comprise 0.1-30 wt% propylene graphene. The battery cell may comprise 0.1-20 wt% propylene graphene. The battery cell may comprise 0.1-20 wt% biochar. The battery cell may comprise 0.1-10 wt% biochar.

[0149] A seventh aspect of the invention provides a method of providing a battery cell,comprising the steps of:

[0150] providing a first slurry composition as a coating on at least one surface of a first substrate thereby providing a positive electrode;

[0151] providing a second slurry composition as a coating on at least one surface of a second substrate thereby providing a negative electrode;

[0152] locating a separator between the positive electrode and the negative electrode such that the positive electrode, the separator and the negative electrode are disposed in a layers as a combined electrode arrangement; locating the combined electrode in a chamber of a battery cell casing; and

[0153] providing electrolyte in the chamber; wherein:

[0154] the a positive electrode comprises one or more of:

[0155] lithium titanium oxide;

[0156] phosphate (1-), hexafluoro- lithium;

[0157] activated graphite;

[0158] activated carbon;

[0159] aluminium;

[0160] cobalt;

[0161] manganese;

[0162] chromium;

[0163] propylene carbonate;

[0164] propylene graphene;

[0165] acetonitrile;

[0166] tetraethylammonium tetrafluoroborate; and / or biochar;

[0167] the negative electrode comprises one or more of:

[0168] lithium titanium oxide;

[0169] phosphate (1-), hexafluoro- lithium;

[0170] activated graphite;

[0171] activated carbon;

[0172] aluminium;

[0173] cobalt;

[0174] manganese;chromium;

[0175] propylene carbonate;

[0176] propylene graphene;

[0177] acetonitrile;

[0178] tetraethylammonium tetrafluoroborate;

[0179] biochar;

[0180] lithium titanate

[0181] lithium cobalt oxide; and / or

[0182] lithium manganese; and

[0183] the electrolyte comprises one or more of:

[0184] lithium titanium oxide;

[0185] phosphate (1-), hexafluoro- lithium;

[0186] activated graphite;

[0187] activated carbon;

[0188] aluminium;

[0189] cobalt;

[0190] manganese;

[0191] chromium;

[0192] propylene carbonate;

[0193] propylene graphene;

[0194] acetonitrile;

[0195] tetraethylammonium tetrafluoroborate;

[0196] biochar; and / or

[0197] lithium hexafluorophosphate.

[0198] The method may comprise adding graphite to the electrolyte and / or to the positive electrode and / or to the negative electrode. The method may comprise adding graphite as a coating on an inner wall portion. The inner wall portion may at least partially surround the chamber. The graphite may make up between 0.1 and 20 wt% of the battery cell, for example 0.1 to 10 wt% of the battery cell.

[0199] The first slurry may comprise one or more of:

[0200] lithium titanium oxide;phosphate (1-), hexafluoro- lithium;

[0201] activated graphite;

[0202] activated carbon;

[0203] aluminium;

[0204] cobalt;

[0205] manganese;

[0206] chromium;

[0207] propylene carbonate;

[0208] propylene graphene;

[0209] acetonitrile;

[0210] tetraethylammonium tetrafluoroborate; and / or biochar.

[0211] The second slurry may comprise one or more of:

[0212] lithium titanium oxide;

[0213] phosphate (1-), hexafluoro- lithium;

[0214] activated graphite;

[0215] activated carbon;

[0216] aluminium;

[0217] cobalt;

[0218] manganese;

[0219] chromium;

[0220] propylene carbonate;

[0221] propylene graphene;

[0222] acetonitrile;

[0223] tetraethylammonium tetrafluoroborate;

[0224] biochar;

[0225] lithium titanate

[0226] lithium cobalt oxide; and / or

[0227] lithium manganese.

[0228] An eighth aspect of the invention provides a battery cell for an electric vehicle comprising:10-40 wt% lithium titanium oxide;

[0229] 0.1-30 wt% graphite; and

[0230] 0.1-25 wt% graphene.

[0231] The battery cell may comprise 1-25 wt% graphene. The battery cell may comprise 5-25 wt% graphene.

[0232] The graphite may in the form of activated graphite. The graphene may be in the form of propylene graphene.

[0233] In some embodiments the battery cell comprises:

[0234] 15-30 wt% lithium titanium oxide;

[0235] 10-20 wt% activated graphite; and

[0236] 10-20 wt% propylene graphene.

[0237] In other embodiments the battery cell comprises:

[0238] 15-30 wt% lithium titanium oxide;

[0239] 0.1-15 wt% activated graphite;

[0240] 0.1-20 wt% propylene graphene; and

[0241] 0.1-15 wt% biochar.

[0242] The battery cell may comprise 10-20 wt% propylene graphene

[0243] The battery cell may further comprise Phosphate(l), Hexafluoro- Lithium; aluminium; cobalt; manganese; chromium; acetonitrile and tetraetheylammonium tetrafluoroborate.

[0244] A nineth aspect of the invention provides a battery cell for an electric vehicle comprising:

[0245] 10-40 wt% lithium titanium oxide;

[0246] 0.1-30 wt% graphite; and

[0247] 5-25 wt% graphene.The graphite may in the form of activated graphite. The graphene may be in the form of propylene graphene.

[0248] In some embodiments the battery cell comprises:

[0249] 15-30 wt% lithium titanium oxide;

[0250] 10-20 wt% activated graphite; and

[0251] 10-20 wt% propylene graphene.

[0252] In other embodiments the battery cell comprises:

[0253] 15-30 wt% lithium titanium oxide;

[0254] 0.1-15 wt% activated graphite;

[0255] 10-20 wt% propylene graphene; and

[0256] 0.1-15 wt% biochar.

[0257] The battery cell may further comprises Phosphate(l-), Hexafluoro-, Lithium; aluminium; cobalt; manganese; chromium; acetonitrile and tetraethylammonium tetrafluoroborate.

[0258] In some preferred embodiments the battery cell comprises:

[0259] 15-30 wt% lithium titanium oxide;

[0260] 10-20 wt% activated graphite;

[0261] 10-20 wt% propylene graphene;

[0262] 1-3 wt% Phosphate(l-), Hexafluoro-, Lithium

[0263] 3-7 wt% aluminium;

[0264] 7-13 wt% cobalt;

[0265] 5-10 wt% manganese;

[0266] <0.01 wt% chromium;

[0267] 5-15 wt% acetonitrile; and

[0268] 1-5 wt% tetraethylammonium tetrafluoroborate.

[0269] In other preferred embodiments the battery cell comprises:

[0270] 15-30 wt% lithium titanium oxide;

[0271] 0.1-15 wt% activated graphite;10-20 wt% propylene graphene;

[0272] 0.1-15 wt% biochar;

[0273] 1-3 wt% Phosphate(l-), Hexafluoro-, Lithium

[0274] 3-7 wt% aluminium;

[0275] 7-13 wt% cobalt;

[0276] 5-10 wt% manganese;

[0277] <0.01 wt% chromium;

[0278] 5-15 wt% acetonitrile; and

[0279] 1-5 wt% tetraethylammonium tetrafluoroborate.

[0280] In preferred embodiment a physical external shape of the battery cell allows for close packing of the cells in a battery module or battery pack. The physical external shape of the battery cell may be in the form of a hexagonal prism.

[0281] A tenth aspect of the invention provides a battery module comprising a plurality of battery cells, each battery cell being according to the nineth aspect of the invention. In preferred embodiments each battery cell in the battery module is in contact with all neighbouring battery cells. In embodiments in which the physical external shape of the battery cell is in the form of a hexagonal prism, the battery cells are preferably arranged in a hexagonal or honeycomb array.

[0282] An eleventh aspect of the invention provides a battery pack comprising two or more battery modules, each battery module being according to the tenth aspect of the invention.

[0283] Preferred and / or optional features of each aspect and embodiment described above may also be used, alone or in appropriate combination, in the other aspects and embodiments also.

[0284] BRIEF DESCRIPTION OF THE DRAWINGS

[0285] The invention will now be further described by way of example only and with reference to the accompanying drawings, in which like reference signs are used forlike features, and in which:

[0286] Figure 1 illustrates a battery cell, a battery module and a battery pack;

[0287] Figure 2a illustrates a known battery cell in the form of a prismatic cell;

[0288] Figure 2b illustrates a known battery cell in the form of a pouch cell;

[0289] Figure 2c illustrates a known battery cell in the form of a cylindrical cell;

[0290] Figure 3 illustrates an array of cylindrical battery cells in a battery pack;

[0291] Figure 4 illustrates an array of battery cells in a battery pack according to a preferred embodiment of the present invention, each of the battery cells having a hexagonal cross-sectional shape;

[0292] Figure 5 illustrates a further battery cell that is similar to the cylindrical battery cell of Figure 2c;

[0293] Figure 6 illustrates the battery cell of Figure 5 in cross section;

[0294] Figure 7 illustrates a pouch battery cell; and

[0295] Figure 8 illustrates the battery cell of Figure 7 in cross section.

[0296] DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0297] Currently most electric vehicle batteries are lithium-ion batteries. Each vehicle battery is in the form of a battery pack 14 that comprises a plurality of battery cells 10. The battery cells 10 may be arranged in battery modules 12, and then the battery modules 12 may be combined to form the battery pack 14, as illustrated in Figure 1.

[0298] Known battery cells have different physical shapes and sizes. As illustrated in Figure2, battery cells may be prismatic or cuboidal (Figure 2a), have a pouch-like shape (Figure 2b), or be cylindrical (Figure 2c).

[0299] One of the disadvantages of current electric vehicles is that their range is limited compared to vehicles having a combustion engine. The energy density of an electric vehicle battery is significantly less than that of petrol or diesel. To achieve an equivalent range, the weight of the battery becomes prohibitive. A further disadvantage is the time taken to charge an electric vehicle battery, which may be more than an hour.

[0300] For optimal performance, battery cells should remain within specified temperature range. To achieve this, known battery modules and battery cells include a cooling mechanism. The cooling mechanism typically includes a flow of fluid through the battery module or battery pack, as illustrated by the arrows in Figure 3. The fluid may be air or a liquid coolant.

[0301] Certain embodiments of the present invention provides a battery suitable for use in an electric vehicle that includes both graphite and graphene. Batteries according to the present invention preferably comprise lithium titanium oxide (LTO) in an amount 10%-40% by weight, graphite in an amount 0.1 %-30%, and graphene in an amount 5%-25% by weight. The graphite may be in the form of activated graphite. The graphene may be in the form of propylene graphene. Batteries according to the present invention may also comprise biochar. The biochar may be present in an amount 0.1 %-20% by weight.

[0302] In some examples, the graphite and the graphene are added together to the battery cell. In some examples, the graphite and the graphene are added individually in various proportions.

[0303] In some alternative examples, the battery may not include graphite. In some alternative examples the battery may not include graphene.

[0304] A first preferred composition of a battery according to the invention is shown in Table1.

[0305] Table 1

[0306] <

[0307]

[0308] A second preferred composition of a battery according to the invention is shown in Table 2.

[0309] Table 2

[0310] <

[0311]

[0312] A third preferred composition of a battery according to the invention is shown in Table 3.

[0313] Table 3

[0314]

[0315] A fourth preferred composition of a battery according to the invention is shown in Table 4.

[0316] Table 4

[0317]

[0318] A fifth preferred composition of a battery according to the invention is shown in Table 5.Table 5

[0319]

[0320] A sixth preferred composition of a battery according to the invention is shown in Table 6.

[0321] Table 6

[0322]

[0323] A seventh preferred composition of a battery according to the invention is shown in Table 7.

[0324] Table 7

[0325]

[0326] An eighth preferred composition of a battery according to the invention is shown in Table 8.

[0327] Table 8

[0328]

[0329] A nineth preferred composition of a battery according to the invention is shown in Table 9.

[0330] Table 9

[0331]

[0332] A tenth preferred composition of a battery according to the invention is shown in Table 10.

[0333] Table 4

[0334]

[0335] An eleventh preferred composition of a battery according to the invention is shown in Table 11.

[0336] Table 11

[0337]

[0338]

[0339] A twelfth preferred composition of a battery according to the invention is shown in Table 12.

[0340] Table 12

[0341]

[0342] A thirteenth preferred composition of a battery according to the invention is shown in Table 13.

[0343] Table 13

[0344]

[0345]

[0346] A fourteenth preferred composition of a battery according to the invention is shown in Table 14.

[0347] Table 14

[0348]

[0349] A fifteenth preferred composition of a battery according to the invention is shown in Table 15.

[0350] Table 15

[0351]

[0352]

[0353] A sixteenth preferred composition of a battery according to the invention is shown in Table 16.

[0354] Table 16

[0355] <

[0356]

[0357] A seventeenth preferred composition of a battery according to the invention is shown in Table 17.

[0358] Table 17

[0359] <

[0360]

[0361]

[0362] Lithium titanium oxide may be described as LTO. Lithium titanium oxide may be described as Li4TisOi2.

[0363] Phosphate(l-), Hexafluoro- Lithium may be described as LiPFe. Phosphate(l-), Hexafluoro-, Lithium may be referred to as lithium hexafluorophosphate.

[0364] Activated graphite comprises carbon (having chemical symbol C). Activated carbon comprises carbon (having chemical symbol C). Aluminium may be referred to as Al. Cobalt may be referred to as Co. Manganese may be referred to as Mn. Chromium may be referred to as Cr. Propylene carbonate may be described as C4H6O3. Propylene graphene may be described as CsHeC. Acetonitrile may be described as CH3CN.

[0365] Tetraethylammonium tetrafluoroborate may be described as Et4NBF4.

[0366] Biochar may be described as CeH-ioNO.

[0367] The battery of any of the examples indicated above (for example at Tables 1 to 17) may optionally further comprise any other components described below (for example with respect to Figures 5 and 6). Additionally or alternatively, the components presented above (for example at Tables 1 to 17) may be included in various compounds (such as metals being provided in oxides and the like). The presence of the components indicated above (for example at Tables 1 to 17) may be included in compounds that differ with the charge / discharge state of the battery.

[0368] Optionally, any of the batteries indicated in the examples above (for example at Tables 1 to 17) may include lithium titanate (Li2TiO3). This may be disposed in the negative electrode of the battery. The lithium titanate may optionally comprise all or a portion of the percentage (by weight) of lithium titanium oxide indicated in the battery examples indicated above (for example at Tables 1 to 17). The lithium titanate may replace all or some of the lithium titanium oxide for any of the batteryexamples indicated above (for example at Tables 1 to 17). Optionally, any of the battery examples indicated above (for example at Tables 1 to 17) may comprise conductive carbon additives. The conductive carbon additives may be located in the negative electrode of the battery.

[0369] Optionally, any of the batteries indicated in the above examples (for example at Tables 1 to 17) may comprise lithium cobalt oxide (LiCoO2). Optionally the lithium cobalt oxide may be disposed in the positive electrode. Optionally, all or some of the cobalt in the battery examples indicated above (for example at Tables 1 to 17) may be provided in lithium cobalt oxide. Optionally, the batteries of the above examples (for example at Tables 1 to 17) may comprise lithium manganese oxide (LiMnO2). Optionally the lithium manganese oxide may be disposed in the positive electrode. Optionally some or all of the manganese indicated in the battery examples indicated above (for example at Tables 1 to 17) is provided in lithium manganese oxide. Optionally some or all of the activated carbon in the battery examples indicated above (for example at Tables 1 to 17) may be provided in the positive electrode.

[0370] Optionally some or all of the lithium hexafluorophosphate (phosphate(l-), hexafluoro-, lithium) indicated in the battery examples illustrated above (for example at Tables 1 to 17) may be provided in electrolyte of the battery. Optionally, the battery examples indicated above examples (for example at Tables 1 to 17) may include carbonate solvents (optionally with additives), optionally disposed in the battery electrolyte.

[0371] Any of the batteries indicated in the above examples (for example at Tables 1 to 17) may instead comprise <0.01 wt% chromium. Any of the batteries indicated in the above examples may instead comprise 0.01-5 wt% chromium.

[0372] Batteries according to the present invention have been found to have the following advantages:

[0373] • Naturally inert and safe

[0374] • Able to operate at temperatures from -40 °C to 80 °C

[0375] • Fast charging, in as little as 6 minutes• Increased lifespan of 20,000 cycles (up to 54 years)

[0376] • High efficiency (99.8% round trip efficiency)

[0377] • Durable and resilient

[0378] • Environmental and safety advantages

[0379] The batteries (according to the present invention) may also have the following advantages:

[0380] • Low cost (for example £0.05 / kWh)

[0381] Due to the ability of the batteries to operate at a greater range of temperatures, it has been found that it is not necessary to provide cooling for battery modules or battery packs comprising battery cells 110 according to the present invention. As such it is possible to pack the battery cells 110 more closely without a risk that the battery cells 110 will overheat and pose a fire risk.

[0382] The ability to more closely pack the battery cells 110 within battery modules 112 and battery packs allows, for a given number of battery cells 110, a smaller battery module 112 and a smaller battery pack to be created compared to prior art battery packs and battery modules. In particular, it is possible to form a battery module 112 or a battery pack in which each of the battery cells 110 in the module or pack is in contact with all of its neighbouring battery cells. This is possible as it is not necessary to leave a flow path for cooling fluid between the battery cells.

[0383] The ability to more closely pack the battery cells 110 within a battery module 112 or battery pack provides the opportunity to create battery cells 110 having different shapes that promote close packing. For example, a battery cell 110 may be in the form of a hexagonal prism (having a hexagonal cross-sectional shape perpendicular to an axis of the battery cell 110), as illustrated in Figure 4. Such hexagonal battery cells 110 may be packed in a hexagonal array (honeycomb array) within a battery module 112 or battery pack.

[0384] In other embodiments, each battery cell may have a generally triangular or square cross-sectional shape.Figure 5 illustrates an example of a battery cell 500. The battery cell 500 may, in some examples, be utilised alone (as a singular battery cell), or may be included in a battery module that includes a plurality of battery cells (as illustrated in Figure 3 and Figure 4, for example). While the battery cell 500 of the illustrated example is generally cylindrical in shape, the battery cell 500 may instead be of any other suitable shape. For example, the battery cell 500 may be in the form of a hexagonal prism (having a hexagonal cross section, with similarity to the battery cells 110 of Figure 4), or may be in the form of a triangular prism (having a triangular cross section), or a rectangular prism (having a rectangular or square cross section), or a pentagonal prism (having a pentagonal cross section), or a heptagonal prism (having a heptagonal cross section), or an octagonal prism (having an octagonal cross section), or a nonagonal prism (having a nonagonal cross section), or a decagonal prism (having a decagonal cross section), or the like. It will be appreciated that a battery cell similar to that shown in Figure 5 but having some of the shapes previously discussed may be able to fit together with other similar battery cells in a battery module in a similarly compact manner as illustrated in Figure 4. As discussed above, the battery cells 110, 500 can be arranged so as to be closely grouped together due to the battery cells 110, 500 not requiring cooling (due to the battery cells 110, 500 being operable over a large range of temperatures).

[0385] Battery cells 500 of the form illustrated in Figure 5 (with consideration of the different shapes the battery cells 500 may ultimately have) may be arranged in a similar manner as the battery cells 10, 110 illustrated in Figures 3 or Figure 4 (depending on the shape of the battery cells 500).

[0386] Figure 5 illustrates how the battery cell 500 has a top surface 510. In the illustrated example, the top surface 510 comprises a metal cover 510 that provides a positive terminal 515 of the battery cell 500. Although not shown in Figure 5, the battery cell 500 also includes a similar bottom surface. The bottom surface comprises a further metal cover that provides a negative terminal of the battery cell 500. In other examples, the top surface may provide a negative terminal and the bottom surface may provide a positive terminal, or the respective negative and positive terminalsmay be disposed at any other suitable positions on the battery cell 500. The top and bottom surfaces may be referred to as top and bottom covers respectively.

[0387] The battery cell 500, of the illustrated example, further includes a generally cylindrical side wall 520. As discussed above, in other examples, the battery cell 500 may have a different shape and thus may have a side wall 520 having a different shape in cross section. For example, the side wall 520 may have a substantially triangular or rectangular (for example square) or pentagonal or hexagonal or heptagonal or octagonal or nonagonal or decagonal shape, or the like.

[0388] The sides of the battery cell 500 are covered with wrapping 530. In the illustrated example, the wrapping 530 is heat shrink wrapping, and thus fits closely to the generally cylindrical battery cell 500 structure. The wrapping 530 extends around the side wall 520. In some examples, the wrapping 530 may also extend partially over the top surface 510 and / or the bottom surface. However, it will be appreciated that at least a portion of the positive terminal 515 and negative terminal of the battery cell 500 (that in the illustrated example are disposed at the top cover 510 and bottom cover respectively) is exposed (that is to say not covered by the wrapping 530). The wrapping 530 helps provide protection for the battery cell 500. In some examples, the battery cell 500 does not include wrapping 530.

[0389] Figure 6 illustrates the battery cell of Figure 5 in cross section. Figure 6 helps illustrate some internal components of the battery cell 500. Figure 6 illustrates how wrapping 530 covers the side portions 604 of the battery cell 500. In the illustrated example, the wrapping 530 covers the generally cylindrical side portion 604 of the battery cell 500. Figure 6 illustrates the top cover 510 and the bottom cover 608 of the battery cell 500. In the illustrated example, the top cover provides a positive terminal 515 and the bottom cover provides a negative terminal 612 of the battery cell 500. The top cover 510 may be referred to as a top plate and the bottom cover 608 may be referred to as a bottom plate. Figure 6 illustrates how the wrapping 530 extends partially over the top and bottom covers 510, 608 leaving at least a portion of the top and bottom covers 510, 608 exposed from the wrapping 530. The positive terminal 515 and the negative terminal 612 are thus exposed. This allows for thebattery cell 500 to provide power and to be charged and the like via electrically coupling the battery cell 500 to external apparatus (such as to other components and / or battery cells of a battery module, or the like).

[0390] Figure 6 illustrates how the battery cell 500 comprises a can 616. The can 616 may be referred to as a canister or container or the like. The can 616 of the illustrated example is generally cylindrical, however it will be understood that the can 616 could be any suitable shape. The can 616 includes at least one side wall 620 (that in the illustrated example is a cylindrical side wall 620 extending circumferentially around the can 616). The can 616 further includes an upper plate 624 and a lower plate 628 that each close respective ends of the can 616. The can includes a chamber 636. The chamber is surrounded by the at least one side wall 620, and extends between the upper and lower plates 624, 628. The chamber 636 is thus enclosed by the at least one side wall 620 and the upper and lower plates 624, 628.

[0391] It will be appreciated that the reference to top and bottom or upper and lower relate to the perspective view illustrated in Figures 5 and 6, and in use the battery cell 500 may be utilised in any desired orientation. Thus, the top cover 510 may instead be referred to as a first cover 510. The bottom cover 608 may instead be referred to as a second cover 608. The upper plate 624 may be referred to as a first plate 624. The lower plate 628 may be referred to as a second plate 628.

[0392] The can 616 extends longitudinally between the upper and lower plates 624, 628. In the illustrated example, the chamber 636 extends longitudinally between the upper and lower plates 624, 628.

[0393] Figure 6 illustrates how the chamber 636 includes a core 640, that may be referred to as a core portion. The core 640 is a generally elongate and extends longitudinally through the chamber 636. The core 640 extends from the upper plate 624 to the lower plate 628. In the illustrated example, the core 640 is generally cylindrical in shape. The core 640 is centrally arranged in the chamber 636. The core 640 is centrally arranged in the can 616.In some examples the core 640 may be made from an electrically conducting or conductive material. In some examples the core 640 may comprise carbon. In some examples the core 640 may comprise graphite. In some examples the core 640 may be hollow, for example having a wall surrounding a central chamber or the like. Such a core 640 may be generally tubular. In some examples the core 640 may be generally solid.

[0394] As shown in Figure 6, a plurality of layers of material are wrapped around the core 640 in the chamber 636. In particular, layers of material providing a positive electrode 644, material providing a negative electrode 648, and material providing a separator 652 are wound around the core 640.

[0395] The positive electrode 644 may be referred to as a cathode. This is because in use (where the battery cell 500 supplies power to external devices) the material providing the positive electrode 644 gains electrons and / or positively charged ions (such as cations). Thus, under such operation, the positive electrode 644 undergoes reduction. However, it will be appreciated that when the battery cell 500 is charged, for example via being connected to a power source, (which is another example of use), the material providing the positive electrode 644 functions as an anode and loses electrons and / or positively charged ions (such as cations). Thus, under such operation, the positive electrode 644 undergoes oxidation.

[0396] The negative electrode 648 may be referred to as an anode. This is because in use (where the battery cell 500 supplies power to external devices) the material providing the negative electrode 648 loses electrons and / or positively charged ions (such as cations). Thus, under such operation, the negative electrode 648 undergoes oxidation. However, it will be appreciated that when the battery cell 500 is charged, for example via being connected to a power source, (which is another example of use), the material providing the negative electrode 644 functions as a cathode and gains electrons and / or positively charged ions (such as cations). Thus, under such operation, the positive electrode 644 undergoes reduction.

[0397] The positive electrode 644, the negative electrode 648 and the separator 652 layersare provided as respective sheets wrapped around the core 640. In some examples, a single positive electrode 644 sheet and a single negative electrode 648 sheet are utilised. In such an example, at least two separator 652 sheets are utilised. Therefore, at least one positive electrode sheet, at least one negative electrode sheet and at least two separator 652 sheets are utilised. In such an example, the sheets are disposed in a stacked manner, with a separator 652 sheet being disposed between the positive electrode 644 sheet and the negative electrode 648 sheet, and a further separator 652 sheet being disposed over the remaining side of either of the electrode 644, 648 sheets. The sheets are then wound around the core 640 a plurality of the times to provide a repeating layer structure around the core 640 defined by the arrangement of the separator 652 and electrode 644, 648 sheets. In such an example, it will be appreciated that the separators 652 and electrodes 644, 648 are each spirally wound. Such a structure is often referred to as a “jelly roll” or “Swiss roll” structure.

[0398] In other examples, a plurality of positive electrode 644 sheets, a plurality of negative electrode 648 sheets and a plurality of separator 652 sheets may be utilised. Such sheets may be spirally wound in a similar manner as described in the paragraph immediately above, or may have other desired arrangements in the battery cell 500, For example, some battery cell arrangements may utilise a separate sheet for each individual layer (wrapped around the core 640 in the chamber 636).

[0399] Figure 6 illustrates the layered or wound electrode structure of the battery cell 500 in more detail. Figure 6 helps illustrate how the positive electrode 644 and the negative electrode 648 are sequentially arranged radially in the chamber 636. The sequential arrangement of the positive electrode 644 and the negative electrode 648 extends radially outwardly from the core 340. That is to say that the positive electrode 644 and the negative electrode 648 are arranged in an alternating manner, and in layers. Put another way, the positive electrode 644 and the negative electrode 648 alternate radially.

[0400] Figure 6 further illustrates how the separator 652 is disposed between each alternating positive electrode 644 and negative electrode 648 layer. Therefore, eachpositive electrode 644 layer and negative electrode 648 layer are separated by the separator 652. Depending on how the sheets that form the layered electrode structure of the battery cell are arranged, it will be appreciated that, optionally, a radially innermost layer (adjacent the core 340) or radially outermost layer (adjacent the can 616) may comprise the separator 652. Alternatively, these layers may comprise the positive or negative electrode 644, 648 as appropriate (for example, depending on the arrangement of the sheets that provide the layered electrode structure).

[0401] The separator 652 acts to separate and isolate the positive electrode 644 and the negative electrode 648. The separator 652 however is made from a permeable (or at least partially permeable) material. The separator 652 may be made from a porous (or at least partially porous) material. The separator 652 may be a microporous material. The separator 652 may be a membrane. The separator may have a thickness of between around 10 and 50 (for example 10 and 30) micrometres. The separator 652 may be made from polymeric material. The separator 652 may comprise polyolefins, or the like. In some examples, the separator 652 may comprise polyethylene (PE) or polypropylene (PP). The separator 652 is configured to permit ion transport through the separator and between the positive electrode 644 and the negative electrode 648.

[0402] The positive electrode 644 may comprise activated carbon. The positive electrode 644 may comprise lithium cobalt oxide (LiCoCh). The positive electrode 644 may comprise lithium manganese oxide (LiMnC ). The positive electrode 644 may comprise activated carbon and lithium cobalt oxide (LiCoC ) and lithium manganese oxide (LiMnC ). The positive electrode 644 may comprise activated carbon with a mixture of lithium cobalt oxide (LiCoC ) and lithium manganese oxide (LiMnC ).

[0403] The positive electrode 644 may comprise one or more of:

[0404] Lithium titanium oxide;

[0405] Phosphate (1 -), hexafluoro-, lithium;

[0406] Activated graphite;

[0407] Activated carbon;Aluminium;

[0408] Cobalt;

[0409] Manganese;

[0410] Chromium;

[0411] Propylene carbonate;

[0412] Propylene graphene;

[0413] Acetonitrile;

[0414] Tetraethylammonium tetrafluoroborate; and / or

[0415] Biochar.

[0416] In some examples, the positive electrode 644 may comprise:

[0417] Lithium titanium oxide;

[0418] Phosphate (1-), hexafluoro-, lithium;

[0419] Activated graphite;

[0420] Activated carbon;

[0421] Aluminium;

[0422] Cobalt;

[0423] Manganese;

[0424] Chromium;

[0425] Propylene carbonate;

[0426] Propylene graphene;

[0427] Acetonitrile;

[0428] Tetraethylammonium tetrafluoroborate; and

[0429] Biochar.

[0430] Phosphate (1-), hexafluoro-, lithium may be referred to as lithium hexafluorophosphate. Phosphate (1), Hexafluoro-, Lithium may be referred to as LiPF6.

[0431] Tetraetheylammonium tetrafluoroborate may be referred to as Et4NBF4.

[0432] The positive electrode 644 may comprise one or more of:

[0433] LTO (Li4Ti50i2);LiPF6;

[0434] C;

[0435] Al;

[0436] Co;

[0437] Mn;

[0438] Cr;

[0439] C4H6O3;

[0440] CsHeC;

[0441] CH3CN;

[0442] Et4NBF4; and / or

[0443] CeHioNO.

[0444] In some examples, the positive electrode 644 may comprise:

[0445] LTO (Li4Ti50i2);

[0446] LiPFe;

[0447] C;

[0448] Al;

[0449] Co;

[0450] Mn;

[0451] Cr;

[0452] C4H6O3;

[0453] CsHeC;

[0454] CHsCN;

[0455] Et4NBF4; and

[0456] CeHioNO.

[0457] The negative electrode 648 may comprise lithium titanate (Li2TiOs). The negative electrode 648 may comprise carbon. The negative electrode 648 may comprise conductive carbon additives. The negative electrode 648 may comprise lithium titanate (Li2TiOs) and carbon. The negative electrode 648 may comprise lithium titanate (Li2TiOs) and conductive carbon additives.

[0458] The negative electrode 648 may comprise one or more of:Lithium titanium oxide;

[0459] Phosphate (1-), hexafluoro-, lithium;

[0460] Activated graphite;

[0461] Activated carbon;

[0462] Aluminium;

[0463] Cobalt;

[0464] Manganese;

[0465] Chromium;

[0466] Propylene carbonate;

[0467] Propylene graphene;

[0468] Acetonitrile;

[0469] Tetraethylammonium tetrafluoroborate; and / or

[0470] Biochar.

[0471] In some examples, the negative electrode 648 may comprise:

[0472] Lithium titanium oxide;

[0473] Phosphate (1-), hexafluoro-, lithium;

[0474] Activated graphite;

[0475] Activated carbon;

[0476] Aluminium;

[0477] Cobalt;

[0478] Manganese;

[0479] Chromium;

[0480] Propylene carbonate;

[0481] Propylene graphene;

[0482] Acetonitrile; and

[0483] Biochar.

[0484] In addition, the negative electrode 648 may further comprise Tetraethylammonium tetrafluoroborate.

[0485] The negative electrode 648 may comprise one or more of:

[0486] LTO (Li4Ti50i2);

[0487] LiPF6;C;

[0488] Al;

[0489] Co;

[0490] Mn;

[0491] Cr;

[0492] C4H6O3;

[0493] CsHeC;

[0494] CH3CN;

[0495] Et4NBF4; and / or

[0496] CeHioNO.

[0497] In some examples, the negative electrode 648 may comprise:

[0498] LTO (Li4Ti50i2);

[0499] LiPFe;

[0500] C;

[0501] Al;

[0502] Co;

[0503] Mn;

[0504] Cr;

[0505] C4H6O3;

[0506] CsHeC;

[0507] CHsCN; and

[0508] CeHioNO.

[0509] In addition, the negative electrode 648 may comprise Et4NBF4.

[0510] The chamber 636 of the can 616 further comprises electrolyte 656. In the illustrated example, the electrolyte 656 is provided as fluid in the chamber 636. The electrolyte 656 solutions may be referred to as electrolyte solution. The electrolyte 656 provides a medium through which ions can pass. Thus, when the battery cell 500 is being discharged (when under load and / or supplying charge / power to a device) or when the battery cell 500 is being charged, the electrolyte facilitates transfer of ions through the separators 652 and to / from the electrodes 644, 648. In other examples, the electrolyte 616 may be provided as a solid or gel or liquid or other fluid. Theelectrolyte 616 may sometimes be referred to as an electrolite.

[0511] The electrolyte 656 may comprise lithium hexafluorophosphate (LiPFe), also referred to as phosphate (1-), hexafluoro-, lithium. The electrolyte 656 may comprise carbonate solvent (or solvent). The electrolyte 656 may comprise additives. The electrolyte 656 may comprise lithium hexafluorophosphate (LiPFe) in carbonate solvents with additives.

[0512] The electrolyte 656 may comprise one or more of:

[0513] Lithium titanium oxide;

[0514] Phosphate (1-), hexafluoro-, lithium;

[0515] Activated graphite;

[0516] Activated carbon;

[0517] Aluminium;

[0518] Cobalt;

[0519] Manganese;

[0520] Chromium;

[0521] Propylene carbonate;

[0522] Propylene graphene;

[0523] Acetonitrile;

[0524] Tetraethylammonium tetrafluoroborate; and / or

[0525] Biochar.

[0526] In some examples, the electrolyte 656 may comprise:

[0527] Phosphate (1-), hexafluoro-, lithium;

[0528] Activated graphite;

[0529] Activated carbon;

[0530] Chromium;

[0531] Propylene carbonate;

[0532] Propylene graphene;

[0533] Acetonitrile; and

[0534] Biochar.

[0535] In addition, the electrolyte 656 may further comprise lithium titanium oxide, and / oraluminium, and / or cobalt, and / or manganese.

[0536] Phosphate (1-), hexafluoro-, lithium may be referred to as lithium hexafluorophosphate. Phosphate (1-), Hexafluoro-, Lithium may be referred to as LiPFe.

[0537] Tetraethylammonium tetrafluoroborate may be referred to as Et4NBF4.

[0538] The electrolyte 656 may comprise one or more of:

[0539] LTO (Li4Ti50i2);

[0540] LiPFe;

[0541] C;

[0542] Al;

[0543] Co;

[0544] Mn;

[0545] Cr;

[0546] C4H6O3;

[0547] CsHeC;

[0548] CH3CN;

[0549] Et4NBF4; and / or

[0550] CeHioNO.

[0551] In some examples, electrolyte 656 may comprise:

[0552] LiPFe;

[0553] C;

[0554] Al;

[0555] Co;

[0556] Mn;

[0557] Cr;

[0558] C4H6O3;

[0559] CsHeC;

[0560] CHsCN; and

[0561] CeHioNO.In addition, the electrolyte 656 may comprise LTO (Li4TisOi2), and / or Al, and / or Co, and / or Mn.

[0562] The positive electrode 644 is connected to the upper plate 624. This may be via one or more suitable tabs or connectors or the like. Similarly, the negative electrode 648 is connected to the lower plate 628. This is also via one or more suitable tabs or connectors or the like. The upper plate 624 thus provides a positive electrode current collector 660. The lower plate 628 provides a negative electrode current collector 664. The respective current collectors 660, 664 act to collect electrons and distribute electrons between the respective electrode 644, 648 and the overall circuit in which the battery cell 500 is disposed in use. In the illustrated example, the positive electrode current collector 660 is electrically connected to the positive terminal 515 while the negative electrode current collector 664 is connected to the negative terminal 612.

[0563] Figure 6 further illustrates how the battery cell 500 includes an insulator element 668 in the form of an insulator ring. The insulator ring 668 provides electrical and thermal insulation to the battery cell 500, and helps protect against thermal runaway. The insulator ring 668 further helps provide mechanical support and physical shock absorption for the battery cell. The insulator ring 668 may be made from a paper material or a polymeric material or the like. The insulator ring 668 can help prevent short circuiting of the battery cell 500 and can act as a barrier between electrically conducting components of the battery cell 500 and a casing of the battery cell 500.

[0564] The battery cell 500 further includes a valve 672. The valve 672 is a safety feature which allows for release of gas from inside the battery cell 500. The valve 672 allows for pressure equalisation, venting of harmful gasses, provides ingress protection, and helps prevent thermal runaway.

[0565] It will be understood that the battery cell 500 includes a general casing 676 that provides the general shape of the battery cell 500, encases the can 616, and provides the physical structure of the battery cell 500.It will be appreciated that, when the battery is in use, ions are transported from one electrode 644, 648 to another in the chamber 636 (through the electrolyte 656 and the separator 652) and electrons are transported out of the battery call 500, through the circuit that that the battery cell 500 forms a part of, and back into the battery cell 500. For example, when the battery cell 500 is providing power to a device, positive ions are transported from the negative electrode 648 to the positive electrode 644, and electrons are transported from the negative electrode 648 to the positive electrode 644 (and out of the negative terminal 612 and into the positive terminal 515). When the battery cell 500 is charging, positive ions are transported from the positive electrode 644 to the negative electrode 648 (through the electrolyte 656 and the separator 653), and electrons are transported from the positive electrode 644 to the negative electrode 648 (and out of the positive terminal 515 and into the negative terminal 612).

[0566] In some examples, the battery cell 500 may comprise graphite. For example, in some examples, the battery cell 500 may comprise additional graphite to the materials discussed above (with respect to the battery cell 500 of Figures 5 and 6). Alternatively, this graphite proportion may refer to the graphite already discussed with respect to this battery cell 500 (described with respect to Figures 5 and 6), for example the activated graphite content discussed above. The battery cell 500 may include between 0 and 10% by weight graphite. The graphite may be included in the positive electrode 644 and / or in the negative electrode 648 and / or in the electrolyte 656. Additionally or alternatively, the inner surface of the can 616 (or a portion thereof) may be coated with graphite.

[0567] As described above, the battery cell may include between 0 and 10% by weight activated graphite. The activated graphite may be disposed in the positive electrode 644, and / or the negative electrode 648 and / or the electrolyte 656. Additionally or alternatively, the activated graphite may be disposed on an inner surface (or portion thereof) of the can 616, for example as a coating. The graphite coating may be applied to the inner surface of the can 616 as a step during manufacture of the battery cell 500.The battery cell 500 of Figures 5 and 6 may be referred to as a “jelly roll” or “Swiss roll” battery cell 500. That is to say that the battery cell 500 of Figures 5 and 6 may be referred to as a “jelly roll” or “Swiss roll” type battery cell 500.

[0568] A plurality of battery cells 500 may be arranged to form a battery module, and a plurality of battery modules may optionally be arranged to form a battery pack.

[0569] The battery cell may comprise any of the compositions indicated in Table 1 to Table 17.

[0570] The battery cell 500 may comprise any of the compositions of (or discussed with respect to) the first to eleventh aspect of the invention indicated above.

[0571] A battery cell with a chemical composition as described throughout the present specification may be referred to as a hybrid battery-supercapacitor system. A battery cell using a chemical composition as described throughout the present specification functions via utilisation of electrostatic reaction (or reactions). This differs from a traditional lithium-ion battery that functions via utilisation of predominantly chemical reaction (or reactions).

[0572] Figure 7 illustrates an alternative battery cell 700. The battery cell 700 of Figure 7 is a pouch type battery cell. The battery cell 700 includes a positive terminal 704 and a negative terminal 708 in the form of tabs. The terminals 704, 708 protrude out from the battery cell housing 712. The housing 712 in the illustrated example is made from a foil material that may be described as a film. The housing 712 may be flexible. The housing 712 may be flexible. The housing 712 may comprise aluminium, or may be made from any other suitable material. In the illustrated example, the housing is a flexible, three-layer aluminium laminated film. Suitably, the housing is between around 100 and 200 micrometres, for example around 150 micrometres.

[0573] Figure 8 illustrates components and / or layers of the battery cell 700 of Figure 7. The battery cell 700 includes the housing 712 on either side of the battery cell 700 toencase the internal components. The housing 712 seals the internal components in the battery cell 700. Figure 7 illustrates how the pouch is formed as a plurality of layers. These layers include at least one layer of a positive electrode 804 (two illustrated in Figure 8) and at least one layer of a negative electrode 808 (one shown in Figure 8). Any suitable number of positive and negative electrode 804, 808 layers can optionally be utilised. The positive and negative electrodes 804, 808 are arranged in an alternating manner. A separator 812 (or separator layer) is disposed between respective positive electrode 804 layers and negative electrode 808 layers. Electrolyte 816 is also disposed in the housing 712 (and is sealed in the battery cell 700 by the housing 712).

[0574] It will be appreciated that a respective positive terminal 704 is connected to (or forms part of) a respective positive electrode 804, and a respective negative terminal 708 is connected to (or forms part of) a respective negative electrode 808.

[0575] The battery cell 700 operates in much the same manner as described with respect to the battery call 500 of Figures 5 and 6.

[0576] The positive electrode 804 may comprise any of the materials discussed with respect the positive electrode 644 of the battery cell 500 of Figures 5 and 6.

[0577] The negative electrode 808 may comprise any of the materials discussed with respect the negative electrode 648 of the battery cell 500 of Figures 5 and 6.

[0578] The separator 812 may comprise any of the materials discussed with respect the separator 652 the battery cell 500 of Figures 5 and 6.

[0579] The electrolyte 816 may comprise any of the materials discussed with respect the electrolyte of the battery cell 500 of Figures 5 and 6.

[0580] The battery cell 700 may, in some examples, further comprise graphite in a similar manner as discussed with respect to the battery cell of Figures 5 and 6. The battery cell 700 may include between 0 and 10% by weight graphite. The graphite may beincluded in the positive electrode 804 and / or in the negative electrode 808 and / or in the electrolyte 816. Additionally or alternatively, the housing inner surface (or a portion thereof) may be coated with graphite.

[0581] In other examples, the battery cell 700 may include the respective layers (including the positive electrode 804, negative electrode 808, and separator 812) arranged in a wound manner in the pouch, similar to the arrangement described for the battery cell 500 of Figures 5 and 6. The wound layers may however, in some examples, have a different shape (for example being substantially flattened or the like).

[0582] A plurality of battery cells 700 may be arranged to form a battery module, and a plurality of battery modules may optionally be arranged to form a battery pack.

[0583] A method of providing a battery cell is described below. The battery cell may be any of the battery cells 10, 110, 500, 700 described herein.

[0584] A first step of providing a battery cell comprises preparing the layers to form the electrically / chemically active portion of the battery cell (such as the electrodes). This may comprise taking strips or sheets of a substrate and coating the same with material to provide at least one positive electrode, and at least one negative electrode. The respective substrates may comprise metal material. For example, the respective substrates may comprise copper and / or aluminium material. For example, the substrate for each positive electrode may comprise aluminium. For example, the substrate for each negative electrode may comprise copper material. The substrates may be foil. The respective substrates may be coated with any or all of the materials described with respect to Figures 5 and 6 (for the positive electrode and the negative electrode of the battery cell 500 respectively) to thereby provide respective positive and negative electrodes.

[0585] In some examples, the material for each electrode is provided to a respective substrate via slurries. Thus, a slurry is applied to a substrate to provide a positive electrode, and a slurry is provided to a substrate to provide a negative electrode.The respective slurry may be provided to a respective substrate in such a manner so as to form a thin film on the surface of the substrate. This may be achieved via blade coating (for example via use of a doctor blade). Additionally or alternatively, this may be achieved via rolling (using rollers). Additionally or alternatively a die may be utilised to shape the slurry. Any other suitable coating method may alternatively be utilised.

[0586] It will be appreciated the slurry for the positive and / or negative electrode are prepared in advance of coating substrates to provide the suitable electrode (as appropriate). The slurries should be thoroughly mixed to ensure homogeneity. The slurry for the positive electrode may comprise any or all of the materials discussed with respect to the positive electrode 644 of the battery cell 500 of Figures 5 and 6. The slurry for the negative electrode may comprise any or all of the materials discussed with respect to the negative electrode 648 of the battery cell 500 of Figures 5 and 6.

[0587] At a second step of the method, the slurry coating, once applied to a substrate, is dried to form the electrode (either the positive electrode or negative electrode as appropriate, depending on the slurry composition and / or the substrate composition). In some examples, the slurry may be dried using air dryers (such as convective air dryers). The slurry may however be dried in any other suitable manner.

[0588] At a third step of the method, the electrodes are shaped. This can include calendaring (for example rolling the electrodes to provide electrodes of desired thickness) and / or cutting the electrodes to a desired shape and / or length and / or width etc. In this stage, the separator sheet(s) may also be shaped (for example calendared and / or cut).

[0589] At a fourth step of the method, the electrodes (and the separator / separators) are arranged in a desired arrangement / orientation, and are placed in a desired battery cell. Thus, in this step, at least one positive electrode, at least one negative electrode and at least one separator are disposed in layers. The layers are disposed such that a separator layer is disposed between each positive electrode layer and a negativeelectrode layer. The layers are provided in respective sheets. In some examples, the stacked arrangement of electrodes (and the at least one separator), forming sheets or layers, is utilised directly in a battery cell (for example in the battery cell 700 of Figures 7 and 8 that is a pouch type cell). This stacked arrangement may thus be placed in a chamber of the battery housing or container in some examples. In other examples, the stacked arrangement of electrode / separator layers are rolled (optionally around a core) to provide spirally wound layers as described with respect to the battery cell 500 of Figures 5 and 6. In such examples, this spirally wound arrangement (forming a “jelly roll” structure) is placed into a battery housing or container (in a chamber thereof).

[0590] At a fifth step of the method, electrolyte is provided in the battery cell. The electrolyte is provided in the chamber in which the electrodes are disclosed. The electrodes are also connected to suitable current collectors (if appropriate), and the battery is sealed (optionally after providing further components, such as safety components, into the battery cell). Optionally, in this step graphite is provided in (or as part of) the electrolyte. Optionally, prior to this step, graphite is provided as a coating on an internal surface of the battery cell container.

[0591] All battery cells disclosed herein may be for (suitable for) an electric vehicle.

[0592] Other modifications and variations not explicitly disclosed above may also be contemplated without departing from the scope of the invention as defined in the appended claims.

Claims

CLAIMS1. A battery cell for an electric vehicle comprising:10-40 wt% lithium titanium oxide;0.1-30 wt% graphite; and0.1-25 wt% graphene.

2. A battery cell according to Claim 1 in which the graphite is in the form of activated graphite and the graphene is in the form of propylene graphene, and wherein the battery cell comprises:15-30 wt% lithium titanium oxide;10-20 wt% activated graphite; and0.1-20 wt% propylene graphene.

3. A battery cell according to Claim 1 in which the graphite is in the form of activated graphite and the graphene is in the form of propylene graphene, and wherein the battery cell comprises:15-30 wt% lithium titanium oxide;0.1-15 wt% activated graphite;0.1-20 wt% propylene graphene; and0.1-15 wt% biochar.

4. A battery cell according to any one of Claims 1 to 3, further comprising Phosphate(l-), Hexafluoro-, Lithium; aluminium; cobalt; manganese; chromium; Acetonitrile and Tetraethylammonium tetrafluoroborate.

5. A battery cell according to Claim 2 or Claim 3, further comprising:1-3 wt% Phosphate(l-), Hexafluoro-, Lithium3-7 wt% aluminium;7-13 wt% cobalt;5-10 wt% manganese;<0.01 wt% chromium;5-15 wt% acetonitrile; and1-5 wt% tetraethylammonium tetrafluoroborate.

6. A battery cell according to any one of Claims 1 to 5, in which a physical external shape of the battery cell is in the form of a hexagonal prism.

7. A battery module comprising a plurality of battery cells, each battery cell being according to any one of Claims 1 to 6.

8. A battery module according to Claim 7 in which each battery cell is in contact with all neighbouring battery cells.

9. A battery module according to Claim 8, in which each battery cell is according to Claim 6, and wherein the battery cells are arranged in a hexagonal or honeycomb array.

10. A battery pack comprising two or more battery modules, each battery module being according to any one of Claims 6 to 9.

11. A vehicle including a battery pack according to Claim 10.

12. A battery cell, comprising:10-40 wt% lithium titanium oxide;1-5 wt% phosphate (1-), hexafluoro-, lithium;1-30 wt% activated carbon;1-10 wt% aluminium;1 -20 wt% cobalt;1-20 wt% manganese;1 -20 wt% propylene carbonate;1-20 wt% acetonitrile; and1-10 wt% tetraethylammonium tetrafluoroborate.

13. A battery cell according to Claim 12, further comprising:0.1-20 wt% activated graphite.

14. A battery cell according to Claim 12 or Claim 13, further comprising:0.1-10 wt% chromium.

15. A battery cell according to any one of Claims 12 to 14, further comprising:0.1-30 wt% propylene graphene.

16. A battery cell according to any one of Claims 12 to 15, further comprising:0.1-20 wt% biochar.

17. A battery cell according to any one of Claims 12 to 16, wherein:a positive electrode of the battery cell comprises one or more of: lithium titanium oxide;phosphate (1-), hexafluoro-, lithium;activated graphite;activated carbon;aluminium;cobalt;manganese;chromium;propylene carbonate;propylene graphene;acetonitrile;tetraethylammonium tetrafluoroborate; and / orbiochar.

18. A battery cell according to any one of Claims 12 to 17, wherein:a negative electrode of the battery cell comprises one or more of: lithium titanium oxide;phosphate (1-), hexafluoro-lithium;activated graphite;activated carbon;aluminium;cobalt;manganese;chromium;propylene carbonate;propylene graphene;acetonitrile;tetraethylammonium tetrafluoroborate; and / orbiochar.

19. A battery cell according to any one of Claims 12 to 18, wherein:an electrolyte of the battery cell comprises one or more of:lithium titanium oxide;phosphate (1-), hexafluoro- lithium;activated graphite;activated carbon;aluminium;cobalt;manganese;chromium;propylene carbonate;propylene graphene;acetonitrile;tetraethylammonium tetrafluoroborate; and / orbiochar.

20. A battery cell according to any one of Claims 12 to 19, wherein:an inner surface portion of a container of the battery cell in contact with an electrolyte comprises a graphite coating, the graphite coating optionally comprising activated graphite.

21. A battery cell, comprising:at least one positive electrode portion comprising activated carbon; at least one negative electrode portion comprising lithium titanateand / or lithium titanium oxide; andelectrolyte comprising lithium hexafluorophosphate.

22. A battery cell according to Claim 21, wherein, the at least one positive electrode portion comprises lithium cobalt oxide and / or lithium manganese oxide.

23. A battery cell according to Claim 21 or Claim 22, further comprising:10-40 wt% lithium titanium oxide;1-5 wt% phosphate (1-), hexafluoro-, lithium;1-30 wt% activated carbon;1-10 wt% aluminium;1 -20 wt% cobalt;1-20 wt% manganese;1 -20 wt% propylene carbonate;1-20 wt% acetonitrile; and1-10 wt% tetraethylammonium tetrafluoroborate.

24. A battery cell according to any one of Claims 21 to 23, further comprising one or more of:0.1-20 wt% activated graphite;0.1-10 wt% chromium;0.1-30 wt% propylene graphene; and / or0.1-20 wt% biochar.

25. A method of providing a battery cell, comprising the steps of:providing a first slurry composition as a coating on at least one surface of a first substrate thereby providing a positive electrode;providing a second slurry composition as a coating on at least one surface of a second substrate thereby providing a negative electrode;locating a separator between the positive electrode and the negative electrode such that the positive electrode, the separator and the negative electrode are disposed in a layers as a combined electrode arrangement; locating the combined electrode in a chamber of a battery cell casing;andproviding electrolyte in the chamber; wherein:the a positive electrode comprises one or more of:lithium titanium oxide;phosphate (1-), hexafluoro- lithium; activated graphite;activated carbon;aluminium;cobalt;manganese;chromium;propylene carbonate;propylene graphene;acetonitrile;tetraethylammonium tetrafluoroborate; and / or biochar;the negative electrode comprises one or more of: lithium titanium oxide;phosphate (1-), hexafluro- lithium; activated graphite;activated carbon;aluminium;cobalt;manganese;chromium;propylene carbonate;propylene graphene;acetonitrile;tetraethylammonium tetrafluoroborate; biochar;lithium titanatelithium cobalt oxide; and / or lithium manganese; andthe electrolyte comprises one or more of: lithium titanium oxide;phosphate (1-), hexafluoro-lithium; activated graphite;activated carbon;aluminium;cobalt;manganese;chromium;propylene carbonate;propylene graphene;acetonitrile;tetraethylammonium tetrafluoroborate; biochar; and / orlithium hexafluorophosphate.

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