US-12626926-B2 - Electrode with flame retardant additives and method and systems for preparation and use

Abstract

Methods and systems are provided for an electrode active material for lithium ion batteries. In one example, the electrode active material may include a lithium mixed metal oxide core and flame-retardant dusting particles partially retained within a surface of the core. In some examples, the dusting particles may have an average size of less than 20 μm. In some examples, the amount of dusting particles by weight may be greater than 0.1% of the core particles and less than 50% of the core particles. In another example, methods are provided for manufacturing the electrode active material for use in a lithium ion battery, where lithium metal composite core particles may be mixed with the flame-retardant dusting particles in a dry process.

Inventors

• Lixin Wang
• Weidong Zhou
• Yao Chen
• Chloe Harrison
• Fu Zhou
• Kitae Kim
• Jun Wang
• Derek C. Johnson

Assignees

• A123 SYSTEMS LLC

Dates

Publication Date

20260512

Application Date

20191011

Claims (18)

1. 1 . An electrode active material for a lithium ion battery, the electrode active material comprising: a lithiated compound core formed of primary particles packed to form secondary particles, wherein the lithiated compound core includes voids within a surface of the lithiated compound core between primary particles increasing a surface area of the lithiated compound core particle; and flame-retardant dusting particles partially retained within the voids within the surface of the lithiated compound core, wherein the flame-retardant dusting particles have an average size of less than 20 μm, wherein an amount of the flame-retardant dusting particles by weight is greater than 0.1% of the electrode active material and less than 50% of the electrode active material, and wherein a coverage of the flame-retardant dusting particles on the lithiated compound core is greater than 50% of an increased surface area of the lithiated compound core and less than 90% of the increased surface area of the lithiated compound core.
2. 2 . The electrode active material of claim 1 , wherein the lithiated compound core is a lithium intercalation compound, a lithium metal oxide, a lithium metal phosphate, or a combination thereof.
3. 3 . The electrode active material of claim 1 , wherein the lithiated compound core is one of NMC, NCA, NCMA, and LFP.
4. 4 . The electrode active material of claim 1 , wherein the flame-retardant dusting particles are composed of one or more of zinc borate, magnesium hydroxide, magnesium oxide, magnesium carbonate, magnesium hydrogen carbonate, aluminum hydroxide, aluminum oxide, aluminum hydroxide oxide, antimony oxide, ammonium sulfate, ammonium carbonate, urea, and polyacrylonitrile.
5. 5 . The electrode active material of claim 4 , wherein the flame-retardant dusting particles are composed of aluminum hydroxide.
6. 6 . The electrode active material of claim 1 , wherein the electrode active material is included in a cathode.
7. 7 . The electrode active material of claim 1 , wherein the electrode active material is included in an anode.
8. 8 . The electrode active material of claim 1 , wherein a height of the flame-retardant dusting particles from the surface of the lithiated compound core varies along the surface of the lithiated compound core.
9. 9 . A method for manufacturing an electrode active material, the method comprising: preparing each of a core powder comprised of one or more electrochemically active materials and a dusting powder comprised of one or more flame-retardant materials, wherein the core power includes primary particles packed to form secondary particles, and wherein the core powder is in the form of particles having an average size of 0.1 to 20 μm; and mixing the core powder with greater than 0.1% by weight of the dusting powder and less than 50% by weight of the dusting powder, such that the dusting powder is partially retained within a void between the primary particles of the core powder, and wherein a coverage of the dusting powder on the core powder is greater than 50% of a surface area of the core powder and less than 90% of the surface area of the core powder.
10. 10 . The method of claim 9 , wherein the core powder is one or more of LiMeO 2 and LiMePO 4 , where Me is one or more elements selected from Ni, Mn, Co, Al, Mg, Y, Nd, B, Ca, V, Fe, Ga, Nb, Cr, Mo, W, Tc, Ru, Rh, Ir, Pd, Cu, Ge, Si, In, Ag, Cd, and Zn.
11. 11 . The method of claim 9 , wherein the core powder is NMC, NCA, NCMA, or LFP.
12. 12 . The method of claim 9 , wherein the one or more flame-retardant materials include one or more of zinc borate, magnesium hydroxide, magnesium oxide, magnesium carbonate, magnesium hydrogen carbonate, aluminum hydroxide, aluminum oxide, aluminum hydroxide oxide, antimony oxide, ammonium sulfate, ammonium carbonate, urea, and polyacrylonitrile.
13. 13 . The method of claim 9 , wherein the mixing is a dry mixing.
14. 14 . The method of claim 9 , wherein the mixing is a wet mixing.
15. 15 . A lithium ion battery, comprising: a positive electrode comprising: a dusted lithium active material, wherein the dusted lithium active material includes a lithium active core formed of primary particles packed to form secondary particles with dusting particles partially covering a surface of the lithium active core and extending partially into voids between primary particles of the lithium active core, the dusting particles having an average size of less than 5 μm, wherein the lithium active core is in the form of particles having an average size of at least 10 μm and at most 20 μm, and wherein a coverage of the dusting particles on the lithium active core is greater than 50% of a surface area of the lithiated compound core and less than 90% of the surface area of the lithiated compound core; a negative electrode comprising at least lithium metal; and an electrolyte.
16. 16 . The lithium ion battery of claim 15 , wherein the dusting particles are composed of one or more of zinc borate, magnesium hydroxide, magnesium oxide, magnesium carbonate, magnesium hydrogen carbonate, aluminum hydroxide, aluminum oxide, aluminum hydroxide oxide, antimony oxide, ammonium sulfate, ammonium carbonate, urea, and polyacrylonitrile.
17. 17 . The lithium ion battery of claim 15 , wherein the dusting particles are greater than 0.1 wt % of the dusted lithium active material and less than 5 wt % of the dusted lithium active material.
18. 18 . The lithium ion battery of claim 15 , wherein the lithium active core is NMC, NCA, NCMA, or LFP.

Description

CROSS REFERENCE TO RELATED APPLICATIONS The present application is a U.S. National Phase of International Application No. PCT/US2019/055997, entitled “ELECTRODE WITH FLAME RETARDANT ADDITIVES AND METHOD AND SYSTEMS FOR PREPARATION AND USE,” filed on Oct. 11, 2019. International Application No. PCT/US2019/055997 claims priority to U.S. Provisional Application No. 62/749,042, entitled “ELECTRODE WITH FLAME RETARDANT ADDITIVES AND METHOD AND SYSTEMS FOR PREPARATION AND USE,” and filed on Oct. 22, 2018. The entire contents of each of the above-identified applications are hereby incorporated by reference for all purposes. FIELD The present description relates generally to an electrode material and methods for preparation and use in lithium ion batteries. BACKGROUND AND SUMMARY Lithium (Li) ion batteries are and have been widely used in a number of different applications, including, but not limited to, consumer electronics, uninterruptible power supplies, transportation, and stationary applications. To meet the increasing demand for energy storage, particularly for use in electric vehicles, attention has shifted towards more energy-dense lithium mixed metal oxide layered structured materials which have high energy density, large voltage windows, and good cycle life compared to other material counterparts. For example, high-nickel positive electrode active materials, such as lithium nickel manganese cobalt oxide (LiNixMnyCo1-x-yO2 or NMC) and lithium nickel cobalt aluminum oxide (LiNixCoyAl1-x-yO2 or NCA), have been used to produce high energy Li ion batteries. These layered LiMO2 compounds offer a higher capacity of up to approximately 200 mAh/g at potentials greater than 3.0 V vs. Li/Li+ compared to other materials. It is desired to continue to increase the energy density of Li ion batteries to meet the demands required by current applications and markets, such as the electric vehicle market. By increasing nickel content or charge voltage of NMC or NCA materials, an improved energy density can be obtained. However, increasing density comes with drawbacks which must be addressed. For example, both high nickel content and overcharge conditions used to achieve high capacity can cause structural thermal instability issues that can lead to thermal runaway or explosion. In this regard, an increased nickel amount results in a larger percentage of surface nickel that is exposed to the electrolyte. Electrolyte molecules are oxidized by Ni3+ or Ni4+ in delithiated cathodes, causing unwanted cathode and electrolyte degradation. During overcharge or overheating abuse conditions, lithium metal oxide layered materials lose O2 and transform into a spinel and rock salt phase. Both the side reactions between cathode and electrolyte and the phase transfer reactions are exothermic and result in the battery temperature rising. The released heat promotes more side reactions to occur between cathode and electrolyte, as well as more phase transfer reactions. When the accumulated heat raises the cell temperature to the electrolyte flash point, the flammable electrolyte initially reacts with O2 via the phase transfer reaction, and then with O2 in air when the cell package is broken by volume expanding during the heat propagation. Fire and explosion are the worst-case scenarios for the thermal runaway. Attempts have been made to prevent the heat propagation reactions and improve battery safety. Surface coatings have been considered but suffer lower ionic/electronic conductivity, leading to lowered rate capability of the coated cathode materials, or the coating materials may be incompatible with the active material, such as NMC or NCA, due to their low working voltages causing degradation to the host materials. In some examples, a structural mismatch may exist between a coating and the substrate material, leading to undesired stacking, which may block the diffusion path for Li ions. In one approach as disclosed in U.S. Patent Application Publication No. 2017/0040600, a flame retardant metal hydroxide is disposed in a hollow part of secondary particles and between primary particles. The material is made through a process whereby NMC is mixed with metal salts. The metal salts are reduced to metal hydroxide by moisture and then the excess moisture is removed. However, since the metal hydroxide is crystalized inside the hollow portion of the cathode particles, the size of the metal hydroxide is not able to be controlled during the drying process resulting in substantial variation which may adversely affect performance. Further, the anions of the metal hydroxide source are left within the material in the process. These extra anions interfere with the electrochemical reaction between cathode and electrolyte, or even dissolve into electrolyte solvent and migrate to the anode side resulting in increased risk of unwanted side reactions. Similarly, an approach shown in U.S. Pat. No. 7,666,551 provides a continuous coating layer which blocks the Li-