# US 12,009,488 B2 · Replenished negative electrodes for secondary batteries > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,009,488 B2 - Document ID: US12009488B2 - Status: Granted - Kind: B2 - Application number: 18/098,285 - Filed: 2023-01-18 - Published: 2023-05-18 - Granted: 2024-06-11 - Earliest claimed: 2015-05-08 - Assignees: Enovix Corporation - Applicants: Enovix Corporation - Inventors: Christopher G. Castledine; David T. Fouchard; Jonathan C. Doan; Christopher J. Spindt; Robert M. Spotnitz; James D. Wilcox; Ashok Lahiri; Murali Ramasubramanian - Web page: https://patentgrep.com/patent/US12009488B2 ## CPC - H01M 10/448: {End of discharge regulating measures} - H01M 4/386: {Silicon or alloys based on silicon} - H01M 10/0525: Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries - H01M 10/446: {Initial charging measures} - H01M 10/48: Accumulators combined with arrangements for measuring, testing or indicating the condition of cells, e.g. the level or density of the electrolyte (constructional details of current conducting connections for detecting conditions inside cells or batteries, e.g. details of voltage sensing terminals, H01M50/569) - Y02E 60/10: Energy storage using batteries - Y02P 70/50: Manufacturing or production processes characterised by the final manufactured product - H01M: PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY - Y02E: REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION - Y02P: CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS ## Abstract A method is provided for activating a secondary battery having a negative electrode, a positive electrode, and a microporous separator between the negative and positive electrodes permeated with carrier-ion containing electrolyte, the negative electrode having anodically active silicon or an alloy thereof. The method includes transferring carrier ions from the positive electrode to the negative electrode to at least partially charge the secondary battery, and transferring carrier ions from an auxiliary electrode to the positive electrode, to provide the secondary battery with a positive electrode end of discharge voltage Vpos,eod and a negative electrode end of discharge so voltage Vneg,eod when the cell is at a predefined Vcell,eod value, the value of Vpos,eod corresponding to a voltage at which the state of charge of the positive electrode is at least 95% of its coulombic capacity and Vneg,eod is at least 0.4 V (vs Li) but less than 0.9 V (vs Li). ## Claims ### Claim 1 A method of cycling a secondary battery between a charged state and a discharged state, the secondary battery comprising a negative electrode, a positive electrode, a microporous separator between the negative and positive electrodes permeated with a carrier ion-containing electrolyte in ionic contact with the negative and positive electrodes, and a controller, wherein the positive electrode comprises a cathodically active material and has a positive electrode coulombic capacity for the carrier ions, the negative electrode comprises anodically active silicon or an alloy thereof and has a negative electrode coulombic capacity for the carrier ions that exceeds the positive electrode coulombic capacity, the controller is programmed with a predefined cell end of charge voltage Vcell,eoc value and a predefined cell end of discharge voltage Vcell,eod value, and the positive electrode has an end of discharge voltage Vpos,eod and the negative electrode has an end of discharge voltage Vneg,eod when the secondary battery is at the predefined Vcell,eod, the value of Vpos,eod corresponds to a voltage at which a state of charge of the positive electrode is at least 95% of its coulombic capacity and Vneg,eod is at least 0.4 V (vs Li) but less than 0.9 V (vs Li), wherein the method comprises cycling the secondary battery by repeatedly charging the secondary battery to the charged state having a cell end of charge voltage that does not exceed the predefined Vcell,eoc value, and discharging the secondary battery to the discharged state having a cell end of discharge voltage that does not exceed the predefined Vcell,eod value. ### Claim 2 (depends on 1) The method of claim 1, wherein the value of Vpos,eod corresponds to a voltage at which the state of charge of the positive electrode is at least 96% of its coulombic capacity and Vneg,eod is at least 0.4 V (vs Li) but less than 0.9 V (vs Li). ### Claim 3 (depends on 1) The method of claim 1, wherein the value of Vpos,eod corresponds to a voltage at which the state of charge of the positive electrode is at least 97% of its coulombic capacity and Vneg,eod is at least 0.4 V (vs Li) but less than 0.9 V (vs Li). ### Claim 4 (depends on 1) The method of claim 1, wherein the value of Vpos,eod corresponds to a voltage at which the state of charge of the positive electrode is at least 98% of its coulombic capacity and Vneg,eod is at least 0.4 V (vs Li) but less than 0.9 V (vs Li). ### Claim 5 (depends on 1) The method of claim 1, wherein the value of Vpos,eod corresponds to a voltage at which the state of charge of the positive electrode is at least 99% of its coulombic capacity and Vneg,eod is at least 0.4 V (vs Li) but less than 0.9 V (vs Li). ### Claim 6 (depends on 1) The method of claim 1, wherein Vneg,eod is at least 0.4 V (vs Li) but less than 0.8 V (vs Li). ### Claim 7 (depends on 1) The method of claim 1, wherein Vneg,eod is at least 0.5 V (vs Li) but less than 0.8 V (vs Li). ### Claim 8 (depends on 1) The method of claim 1, wherein Vneg,eod is at least 0.4 V (vs Li) but less than 0.7 V (vs Li). ### Claim 9 (depends on 1) The method of claim 1, wherein Vneg,eod is at least 0.5 V (vs Li) but less than 0.7 V (vs Li). ### Claim 10 (depends on 1) The method of claim 1, wherein the carrier ions are lithium, sodium, potassium, magnesium or aluminum ions. ### Claim 11 (depends on 1) The method of claim 1, wherein the carrier ions are lithium, magnesium or aluminum ions. ### Claim 12 (depends on 1) The method of claim 1, wherein the carrier ions are lithium ions. ### Claim 13 (depends on 1) The method of claim 1, wherein the carrier ions are magnesium ions. ### Claim 14 (depends on 1) The method of claim 1, wherein the negative electrode comprises a microstructured silicon-containing active material that contains a significant void volume fraction to accommodate volume expansion and contraction as carrier ions are incorporated into or leave the negative electrode during charging and discharging cycles. ### Claim 15 (depends on 14) The method of claim 14, wherein the void volume fraction of the microstructured silicon-containing active material is at least 0.1. ### Claim 16 (depends on 14) The method of claim 14, wherein the void volume fraction of the microstructured silicon-containing active material is not greater than 0.8. ### Claim 17 (depends on 14) The method of claim 14, wherein the void volume fraction of the microstructured silicon-containing active material is about 0.15 to about 0.75. ### Claim 18 (depends on 14) The method of claim 14, wherein the void volume fraction of the microstructured silicon-containing active material is about 0.2 to about 0.7. ### Claim 19 (depends on 14) The method of claim 14, wherein the void volume fraction of the microstructured silicon-containing active material is about 0.25 to about 0.6. ### Claim 20 (depends on 14) The method of claim 14, wherein the microstructured silicon-containing active material comprises macroporous, microporous or mesoporous material layers or a combination thereof.