# US 12,191,460 B2 · Asymmetric battery pack with varied electrode and current collector properties to achieve C-Rate balancing > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,191,460 B2 - Document ID: US12191460B2 - Status: Granted - Kind: B2 - Application number: 17/744,002 - Filed: 2022-05-13 - Published: 2022-12-15 - Granted: 2025-01-07 - Earliest claimed: 2019-06-20 - Assignees: Apple Inc. - Applicants: Apple Inc. - Inventors: Loren L. Roy; Qingzhi Guo; Premanand Ramadass; Hyungook Yoon; Jinjun Shi - Web page: https://patentgrep.com/patent/US12191460B2 ## CPC - H01M 4/661: {Metal or alloys, e.g. alloy coatings (H01M4/669 take precedence)} - H01M 10/441: {for several batteries or cells simultaneously or sequentially} - H01M 4/13: Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof - H01M 4/70: characterised by shape or form - H01M 10/0431: {Cells with wound or folded electrodes (H01M10/045 takes precedence)} - H01M 10/0525: Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries - H01M 10/0587: of accumulators having only wound construction elements, i.e. wound positive electrodes, wound negative electrodes and wound separators - H01M 10/4207: {for several batteries or cells simultaneously or sequentially} - H01M 50/103: prismatic or rectangular (H01M50/109, H01M50/11 take precedence) - H01M 50/112: Monobloc comprising multiple compartments - H01M 50/538: Connection of several leads or tabs of wound or folded electrode stacks - H01M 50/534: characterised by the material of the leads or tabs - H01M 2010/4292: {Aspects relating to capacity ratio of electrodes/electrolyte or anode/cathode} - H01M 2220/30: Batteries in portable systems, e.g. mobile phone, laptop - 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 Battery packs having jelly roll battery cells of different designs or capacities may have an imbalance in the charging and/or discharging current supplied to and provided by each jelly roll due to differences in capacity specific impedance between the battery cells of the battery pack. A C-rate (i.e., current relative to rated capacity) of a first and second battery cell connected in parallel may be balanced by altering properties of an active layer and/or a thickness of a current collector of the second battery cell to reduce an impedance of the second battery cell. ## Claims ### Claim 1 A method for balancing a C-rate of an asymmetric battery pack, the method comprising: packaging a first jelly roll battery cell and a second jelly roll battery cell into the asymmetric battery pack, first jelly roll battery cell comprising a first battery design and the second jelly roll battery cell comprising a second battery design, wherein the second battery design is different than the first battery design; balancing a C-rate of the second jelly roll battery cell with a C-rate of the first jelly roll battery cell by increasing a thickness of a current collector of a cathode layer of the second jelly roll battery cell to reduce an impedance of the second jelly roll battery cell; and connecting the first jelly roll battery cell and the second jelly roll battery cell in parallel. ### Claim 2 (depends on 1) The method of claim 1, wherein an in-plane impedance of the current collector of the cathode layer of the second jelly roll battery cell is less than an in-plane impedance of a current collector of the first jelly roll battery cell. ### Claim 3 (depends on 1) The method of claim 1, further comprising increasing a thickness of a current collector of an anode layer of the second jelly roll battery cell. ### Claim 4 (depends on 3) The method of claim 3, wherein an in-plane impedance of the current collector of the anode layer of the second jelly roll battery cell is less than an in-plane impedance of a current collector of the first jelly roll battery cell. ### Claim 5 (depends on 1) The method of claim 1, further comprising reducing a thickness of an active layer of the cathode layer of the second jelly roll battery cell. ### Claim 6 (depends on 5) The method of claim 5, wherein a thru-plane impedance of the active layer of the cathode layer of the second jelly roll battery cell is less than a thru-plane impedance of an active layer of the first jelly roll battery cell. ### Claim 7 (depends on 1) The method of claim 1, further comprising reducing a thickness of an active layer of an anode layer of the second jelly roll battery cell. ### Claim 8 (depends on 7) The method of claim 7, wherein a thru-plane impedance of the active layer of the anode layer of the second jelly roll battery cell is less than a thru-plane impedance of an active layer of the first jelly roll battery cell. ### Claim 9 (depends on 1) The method of claim 1, wherein the first battery design of the first jelly roll battery cell further comprises a first capacity and the second battery design of the second jelly roll battery cell further comprises a second capacity that is greater than the first capacity. ### Claim 10 (depends on 1) The method of claim 1, wherein the first battery design of the first jelly roll battery cell further comprises a first capacity; and the second battery design of the second jelly roll battery cell further comprises a second capacity, wherein the second capacity is the same as the first capacity.