New and old hybrid battery module and hierarchical control method and system thereof

Abstract

The invention belongs to the technical field of batteries, discloses a new and old hybrid battery module and a hierarchical control method and system thereof, and aims to solve the problems of high thermal runaway risk of an existing battery module and echelon utilization of retired batteries. The module is formed by alternately arranging brand-new battery arrays and aged battery arrays in space, the charge state of each aged battery is configured to be lower than a preset safety threshold value, the threshold value is a critical value that energy released by thermal runaway of adjacent brand-new batteries is not enough to trigger thermal runaway of the adjacent brand-new batteries, and therefore an active safety barrier is formed on a thermal propagation path. According to the hierarchical control method, new and old batteries are respectively constructed into independent charging and discharging branches, a brand new battery branch is preferentially used during charging and discharging, and the charge state of an aged battery branch is continuously controlled below a safety threshold. According to the system, through cooperation of structural design and control strategies, the thermal safety boundary and operation reliability of the module are remarkably improved, meanwhile, high-value utilization of the retired battery is achieved, and the system has the advantages of being low in cost, good in performance consistency and the like.

Description

Technical Field

[0001] This invention belongs to the field of battery technology, specifically relating to a hybrid battery module and its hierarchical control method and system. Background Technology

[0002] With the rapid development of electric vehicles and energy storage systems, lithium-ion batteries have been widely used due to their high energy density and long cycle life. However, battery safety, especially thermal runaway, remains a key challenge restricting their large-scale application. In battery modules composed of multiple individual cells connected in series or parallel, if a single cell triggers thermal runaway due to internal short circuits, overcharging, or mechanical abuse, it releases a large amount of heat, which can easily ignite or trigger thermal runaway in adjacent cells, leading to a chain reaction of thermal runaway within the module and causing serious fires or explosions. Currently, the industry mainly addresses the issue of heat propagation in battery modules by optimizing thermal management design, adding heat insulation materials, and installing pressure relief valves. However, these methods are often costly, complex, and difficult to fundamentally block the transmission path of high temperatures and flames.

[0003] Meanwhile, as early-used power batteries gradually enter their retirement period, how to achieve their environmentally friendly and economical tiered utilization has become a key issue. Retired batteries typically exhibit aging phenomena such as capacity decay and increased internal resistance. While reassembling them into modules composed entirely of aged batteries can achieve resource reuse, the overall performance, consistency, and safety of such modules are often poor, with a higher risk of thermal runaway, thus limiting their application value.

[0004] Therefore, existing technologies present two prominent problems: first, brand-new high-performance battery modules face severe risks of thermal runaway propagation, making safety design complex and costly; second, the cascade utilization schemes for retired batteries often sacrifice the overall performance and safety of the system, making them difficult to apply in demanding scenarios. Currently, there is a lack of an integrated technology solution that can effectively combine the characteristics of new and old batteries, significantly improve the thermal safety boundary of the module, and achieve high-value utilization of retired batteries. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a hybrid battery module, a hierarchical control method, and a management system. Through the synergistic optimization of structural design and control strategies, it achieves high-efficiency compatibility between new and aged individual battery cells, constructs an active thermal safety barrier, and simultaneously improves the energy utilization efficiency and operational reliability of the module.

[0006] To achieve the above objectives, the present invention provides the following technical solution: A hybrid battery module comprising at least one new battery array consisting of new individual cells and at least one aged battery array consisting of aged individual cells; wherein the state of charge of the aged individual cells is configured to be below a preset threshold, the preset threshold being a critical value that can be triggered by the energy released by an adjacent new individual cell in a state of complete thermal runaway; the new battery array and the aged battery array are arranged alternately in space and electrically connected, such that the new battery array and the aged battery array are spaced apart from each other in the heat propagation path.

[0007] Preferably, the alternating arrangement is a layered alternating arrangement; wherein, the new battery array is composed of several new individual batteries arranged along the width direction of the battery module, forming a new battery layer; the aged battery array is composed of several aged individual batteries arranged along the width direction of the battery module, forming an aged battery layer; the number of individual batteries in the new battery array and the aged battery array is the same; the new battery layer and the aged battery layer are arranged alternately in the width direction of the battery module.

[0008] Preferably, the alternating arrangement is a column-like alternating arrangement; wherein, the new battery array is composed of several new individual cells arranged along the thickness direction of the battery module, forming a new battery layer; the aged battery array is composed of several aged individual cells arranged along the thickness direction of the battery module, forming an aged battery column; the number of individual cells in the new battery array and the aged battery array is equal; the aged battery column to which the new battery column belongs is alternately arranged in the width direction of the battery module to which it belongs.

[0009] Preferably, the alternating arrangement follows this pattern: every P new battery arrays are followed by Q aged battery arrays, where P and Q are integers greater than or equal to 1. By adjusting the values ​​of P and Q, the module can be adapted to different capacity requirements, space constraints, and performance indicators, thereby improving its versatility and adaptability.

[0010] Preferably, the present invention provides a graded control method for a hybrid battery module, applied to the hybrid battery module, the method comprising: connecting the new single cells in series to form a first branch, and connecting the aged single cells in series to form a second branch; performing graded charge-discharge control: during the discharge phase, prioritizing charging the first branch, and initiating discharge of the second branch when the first branch is insufficient; during the charging phase, prioritizing charging the first branch to ensure the energy reserve of the new single cells. Throughout the process, the state of charge of the aged single cells in the second branch needs to be continuously controlled to maintain it within a preset range below the thermal runaway trigger threshold, ensuring the continued effectiveness of the safety barrier.

[0011] Preferably, the present invention also provides a battery management system for a hybrid battery module, applied to the hybrid battery module. The system includes: an anomaly detection module, used to detect abnormal states of the new and aged individual cells, and to collect key parameters such as voltage, temperature, state of charge, and loop current of the new and aged individual cells in real time and accurately, providing data support for the execution of subsequent control strategies; and a hierarchical control module, connected to the anomaly detection module, configured to execute the hierarchical control method, and further configured to: when the anomaly detection module detects an anomaly in the first or second branch, execute an anomaly handling strategy, the strategy including: disconnecting the abnormal branch from the external circuit and controlling the abnormal branch to discharge through the built-in load; selectively controlling another non-abnormal branch to discharge according to the power supply requirements of the external circuit, or controlling the first and second branches to discharge simultaneously. Its core function is to execute the above-mentioned hierarchical charge and discharge control method, that is, to dynamically switch the charge and discharge branches and control the charge and discharge current distribution based on the battery state data fed back by the state monitoring module, so as to improve the safety of the battery module.

[0012] Compared with existing technologies, the advantages of this invention are: superior safety performance, by adjusting the state of charge of aged batteries to be lower than the thermal runaway threshold of new batteries to form an "energy trough" to block heat propagation; the flexible arrangement of "P new, Q old" combined with a graded charging and discharging strategy can effectively alleviate the performance differences between new and old batteries and extend the overall lifespan of the module; more reasonable cost control, by adopting a mode of using new batteries as the main power source and aged batteries as supplementary power sources, fully exploring the remaining value of retired batteries and significantly reducing the module manufacturing cost; and higher operational reliability, with the management system achieving proactive control of the entire module process through real-time monitoring, dynamic adjustment, and flexible anomaly handling. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of a layered structure provided by the present invention, in which a column of aged batteries is arranged along the width direction of the battery module and an aged battery column is set every other column of new batteries.

[0014] Figure 2 This is a schematic diagram of a layered structure provided by the present invention, in which a column of aged batteries is arranged along the width direction of the battery module and an aged battery column is set every two columns of new batteries.

[0015] Figure 3 This is a schematic diagram of a column structure provided by the present invention, in which a column of aged batteries is arranged along the thickness direction of the battery module and an aged battery column is set every other column of new batteries.

[0016] Figure 4This is a schematic diagram of a column structure provided by the present invention, in which batteries are arranged along the thickness direction of the battery module and an aged battery column is set every two columns of new batteries.

[0017] In all the above diagrams: 1. Brand new single cell, 2. Aged single cell, 3. Aged battery array, 4. Brand new battery array. Detailed Implementation

[0018] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention and are only used to explain the present invention, not to limit the scope of the present invention.

[0019] Combination Figures 1-2 This embodiment discloses a hybrid battery module comprising at least one new battery array (4) composed of new single cells (1) and at least one aged battery array (3) composed of aged single cells (2). The array design confines the performance differences between the new and aged batteries within their respective regions, avoiding mutual interference. The state of charge of the aged single cells is configured to be below a preset threshold, which is a critical value that can be triggered by the energy released by adjacent new single cells in a state of complete thermal runaway. The new battery array and the aged battery array are spatially alternately arranged and electrically connected, such that the new battery array and the aged battery array are spaced apart in the heat propagation path.

[0020] The core safety design of this embodiment lies in the state of charge (SOC) management of the aged battery array: before and during the use of aged batteries, the battery management system continuously controls and maintains their SOC at a low level, which is strictly below a preset safety threshold. The safety threshold is defined by experiments or simulations as "the critical SOC value at which the total heat transferred to adjacent aged cells when a brand-new single cell completely thermally runs away is just insufficient to trigger the latter's thermal runaway."

[0021] The alternating arrangement is a layered alternating arrangement; the new battery array is composed of several new individual batteries arranged along the width direction of the battery module, forming a new battery layer; the aged battery array is composed of several aged individual batteries arranged along the width direction of the battery module, forming an aged battery layer; the number of individual batteries in the new battery array and the aged battery array is equal; the new battery layer and the aged battery layer are arranged alternately in the thickness direction of the battery module.

[0022] In terms of spatial arrangement, new battery layers and aged battery layers are stacked alternately along the thickness direction of the module, forming a "high-energy-low-energy" spacing structure. This structure naturally blocks the vertical heat propagation path: when a single cell in a new battery layer experiences thermal runaway, the upward or downward thermal shock must pass through the adjacent aged battery layer. Due to the low state of charge, fewer internal active materials, and weak reaction driving force of the aged battery array, it can effectively absorb and block heat, preventing thermal runaway from penetrating the entire module, achieving dual thermal protection of "physical separation + chemical stability". The core is to construct a thermal safety barrier through arrayed spacing in the thickness direction, balancing structural compactness and safety.

[0023] Combination Figures 3-4 Another hybrid battery module in this embodiment includes at least one new battery array (4) composed of at least one new single cell (1), and at least one aged battery array (3) composed of at least one aged single cell (2). The array design limits the performance differences between the new and old batteries to their respective regions, avoiding mutual interference. The state of charge of the aged single cell is configured to be below a preset threshold, which is a critical value that can be triggered by the energy released by the adjacent new single cell in a state of complete thermal runaway. The new battery array and the aged battery array are arranged alternately in space and electrically connected, so that the new battery array and the aged battery array are spaced apart from each other in the heat propagation path.

[0024] The core difference from Embodiment 1 lies in the alternating arrangement dimension, achieving lateral thermal runaway prevention through arrayed intervals in the width direction. Specifically, the alternating arrangement is a column-like alternating arrangement; the new battery array consists of several new individual cells arranged along the thickness direction of the battery module, forming a new battery column; the aged battery array consists of several aged individual cells arranged along the thickness direction of the battery module, forming an aged battery column; the number of individual cells in the new battery array and the aged battery array is equal; the new battery column and the aged battery column are arranged alternately in the width direction of the battery module.

[0025] This embodiment adopts the core safety mechanism of Embodiment 1: the state of charge of the aged battery array is strictly controlled by the battery management system to be below the aforementioned safety threshold, forming a "vertical fireproof barrier" composed of low-energy aged batteries along the horizontal heat propagation path. When a single cell in a brand-new battery array experiences thermal runaway, the flames, high-temperature gases, and particles spreading to the left or right will first impact adjacent aged battery arrays. Due to the high thermal stability and resistance to ignition of the aged battery array, the thermal runaway event can be confined to a local area, effectively preventing its large-scale lateral spread and ensuring the overall safety of the battery module.

[0026] The battery management systems of the modules in the two embodiments described above implement a unified hierarchical control strategy, achieving a balance between performance and safety through "independent branch management + priority scheduling." This strategy specifically includes three parts: branch construction, hierarchical charging and discharging, and anomaly handling. In the branch construction stage, the battery management system connects all the individual cells of the new battery array in series to form the first branch through an internal switch matrix or pre-connected physical connections, while simultaneously connecting all the individual cells of the aged battery array in series to form the second branch. The two branches are electrically connected in parallel to the module's total output terminal, thereby achieving independent power supply and precise control of new and old batteries. The graded charge and discharge management revolves around the principle of "new as primary and old as secondary". During discharge, when the load requests discharge, the battery management system prioritizes the first branch (new battery) to ensure the stability and efficiency of the output. At the same time, it monitors the voltage, current and state of charge of the first branch in real time. Only when the state of charge of the first branch drops to a low level or the output power cannot meet the load demand will the corresponding switch be closed to start the second branch (aged battery) to participate in the discharge, ensuring the continuity of power supply. During charging, when an external charger is connected, the battery management system prioritizes charging the first branch. In principle, the second branch will not be charged before its state of charge reaches the set value to maintain the low state of charge of the aged battery. Only when the first branch is fully charged or when it is required according to the balancing strategy will the second branch be given a small amount of supplementary charging, and its state of charge will be strictly controlled below the safety threshold to ensure the continuous effectiveness of the thermal barrier function.

[0027] Anomaly handling strategies are a crucial component of tiered control. The battery management system (BMS) continuously monitors the status of each cell and branch, implementing differentiated responses to anomalies in different branches. When an anomaly occurs in the first or second branch, if the BMS detects a severe situation such as a sudden voltage drop or a rapid temperature rise in a cell, it will immediately disconnect that branch from the external circuit. Simultaneously, it will control the cell to urgently discharge through its internal load to quickly reduce chemical energy. If necessary, it can activate another normal branch to maintain basic power supply, mitigating the risk of heat propagation at its source. If there is no urgent power demand from the external circuit, if the BMS detects an anomaly in a branch, it can selectively execute a handling plan. It can either control only the other normal branch to discharge or control the first and second branches to discharge simultaneously, reducing the overall energy of the module to a safe level as quickly as possible and preventing the risk from spreading.

[0028] To adapt to different scenario requirements, the above embodiments can be modified in various ways to further improve module performance and adaptability. The spacing ratio between new and aged battery arrays can be flexibly adjusted according to capacity requirements and safety levels, for example: Figure 4 "One row of aged batteries is set after every two rows of brand new batteries" (P=2, Q=1) Figure 1"Each new battery layer is followed by an aged battery layer" (P=1, Q=1), where P and Q are integers greater than or equal to 1. The state-of-charge (SOC) safety threshold of the aged batteries can be precisely calibrated experimentally and stored as parameters in the battery management system. The battery management system estimates the SOC of the aged batteries in real time and dynamically maintains it below the threshold by combining charge and discharge control, ensuring the safety barrier remains effective. The module can also integrate thermal management components such as liquid cooling plates, whose flow channel design can enhance cooling for the new battery array area, further reducing the risk of thermal runaway and adapting to high-power operation scenarios. In distributed scenarios, the battery management system can be equipped with an IoT module to push alarm information to the user's mobile terminal when an anomaly is detected, improving safety and convenience.

[0029] The technical solution described in this specific embodiment physically embeds an array of aged batteries with low state of charge between a high-energy-density array of new batteries using a layered or column-like alternating array arrangement, thus constructing an intrinsic heat propagation barrier. Combined with a hierarchical control strategy of "new as primary, old as secondary," it ensures that the system utilizes the new batteries to achieve high performance while ensuring that the aged batteries remain in a safe state to fulfill their safety functions. This solution synergistically enhances safety at two core levels: at the battery level, it actively regulates the state of charge to reduce the chemical energy of the aged batteries, thereby improving their thermal stability; at the system structure level, it sets physical barriers along the heat propagation path through array spacing. Simultaneously, this technology provides a high-value, high-safety application outlet for retired batteries, achieving a balance between safety performance, output performance, and economic benefits.

[0030] The above description is merely a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A hybrid battery module, characterized in that, include: At least one new battery array (4) consisting of new single cells (1) and at least one aged battery array (3) consisting of aged single cells (2); the state of charge of the aged single cells is configured to be below a preset threshold, the preset threshold being a critical value that can be triggered by the energy released by the adjacent new single cells in a state of complete thermal runaway; the new battery array and the aged battery array are arranged alternately in space and electrically connected, such that the new battery array and the aged battery array are spaced apart from each other in the heat propagation path.

2. The hybrid battery module according to claim 1, characterized in that, The alternating arrangement is a layered alternating arrangement; wherein, the new battery array is composed of several new individual batteries arranged along the width direction of the battery module, forming a new battery layer; the aged battery array is composed of several aged individual batteries arranged along the width direction of the battery module, forming an aged battery layer; the number of individual batteries in the new battery array and the aged battery array is equal; the new battery layer and the aged battery layer are arranged alternately in the thickness direction of the battery module.

3. The hybrid battery module according to claim 1, characterized in that, The alternating arrangement is a column-like alternating arrangement; wherein, the new battery array is composed of several new individual batteries arranged along the thickness direction of the battery module, forming a new battery column; the aged battery array is composed of several aged individual batteries arranged along the thickness direction of the battery module, forming an aged battery column; the number of individual batteries in the new battery array and the aged battery array is equal; the new battery column and the aged battery column are arranged alternately in the width direction of the battery module.

4. The hybrid battery module according to claim 2 or 3, characterized in that, The alternating arrangement follows this rule: every P new battery arrays are followed by Q aged battery arrays, where P and Q are integers greater than or equal to 1.

5. A graded control method for hybrid battery modules, characterized in that, The method, applied to a hybrid battery module of new and old as described in any one of claims 1 to 4, comprises: connecting the new single-cell batteries in series to form a first branch, and connecting the aged single-cell batteries in series to form a second branch; performing graded charge and discharge control: during the discharge phase, discharging is preferentially carried out through the first branch, and when the first branch is insufficient to discharge, the second branch is started to discharge; during the charging phase, the first branch is preferentially charged.

6. A battery management system for a hybrid battery module, characterized in that, The system, applied to a hybrid battery module of any one of claims 1 to 4, comprises: an anomaly detection module for detecting abnormal states of the new and aged individual cells; and a hierarchical control module connected to the anomaly detection module, configured to execute the hierarchical control method as described in claim 5, and further configured to: when the anomaly detection module detects an anomaly in a first branch or a second branch, execute an anomaly handling strategy, the strategy comprising: disconnecting the abnormal branch from an external circuit and controlling the abnormal branch to discharge through a built-in load; selectively controlling another non-abnormal branch to discharge, or controlling the first and second branches to discharge simultaneously, according to the power supply requirements of the external circuit.

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