1. Platform establishment for characterization of retired batteries, design, integration, testing of power system including: (a) Develop & build data acquisition system to simultaneously measure & record individual voltages, capacity, direct current resistance, state of charge (up to 120 values) of different types Li-ion battery cell (for example, LiFePO4, NMC or LMO etc.) . (b) Setup communication interface between data acquisition system & programmable charge/discharge testing equipment to facilitate relevant control of charge/discharge experiments (c) Build hardware and software for design, integration, testing of backup power system (48V/20Ah) 2. Methodology development of retired battery screening: (a) Design of retired battery screening tests, testing profile and testing conditions; (b) Comprehensive charge/discharge experimental investigation for optimal key battery characteristics selection of battery screening and for verification of fast battery screening methodology (c) ‘Software-based prescreening’ algorithms development for automating (i) preliminary selection; and (ii) extraction of primary electrical parameters/characteristics from selected Li-ion cells/modules (d) Finalization of retired battery screening methodology including testing setup, testing procedures, testing parameters/conditions, and screening software to achieve less than 2 hours per battery cell screening, and 95% characteristics uniformity 3. Methodology development for thermo-mechanical design, and system optimization of ‘eco-friendly power system’: (a) Mechanical and thermal design of “eco-friendly power system” through thermo-mechanical modelling and simulation to achieve size <350mmx450mmx200mm and operation temperature requirement at -400C~550C (b) Develop control algorithms and simulation to implement real-time energy system monitoring, comprising (i) estimation of non-measurable properties (State-Of-Charge, State-Of-Health); (ii) charge equalization between individual Li-ion modules; and (iii) fail-safe control strategies (c) Develop “Artificial Intelligence Learning” algorithms and simulation for system optimization to keep track of and update deviation of electrical parameters for associated Li-ion modules (d) Develop device firmware to control/interface with other electronic/electrical peripherals (e) Design system-level electrical schematics, and hardware of main controller of ‘eco-friendly power system’ 4.Buildup prototype of “eco-friendly power system”: (a) Fabricate the casing of ‘eco-friendly power system’, and test the mechanical and thermal properties of the system case (b) Fabricate the battery module and test the electrical properties to achieve 48V/20Ah requirement (c) Fabricate the battery module encapsulation of phase change material and characterize its thermal properties (d) Fabricate the battery management system and test all its functions for meeting the safety requirement of IEC62109-1/2 & IEC62040-1 (e) Perform system integration and tests to assure the functionality and robustness of all components (f) Conduct long-term reliability assessment against overall system, including evaluation of (i) data acquisition accuracy; (ii) effectiveness of parameters identification & estimation; (iii) charge equalization efficacy; (iv) noise immunity for intercommunication channels; and (v) robustness of fail-safe mechanisms (g) Comprehensive system analysis and tuning to optimize overall system performance
AAB Technology (HK) Limited [Sponsor]
China Dynamics New Energy Technology Company Limited [Sponsor]
Supergold Technology (Hong Kong) Co. Ltd. [Sponsor]
The core project objective is to salvage those retired EV batteries and thus alleviating their potential negative environmental impacts. Despite such retired EV batteries will no longer fit for automotive applications, their remaining energy storing capacity actually retains approximately 70% of the original. For this sake, we should consider reusing such retired batteries for stationary energy storage to preserve our natural resources. A feasible approach is the deployment for 5G base stations back-up power. Referring to Bloomberg NEF (New Energy Finance), worldwide stockpile of retired EV battery packs is expected to exceed 3.4 million in 2025. From technical perspective, relevant cumulative energy capacity will be around 95 GWh. Developing second-life applications for retired lithium batteries will undoubtedly promote their sustainability, and hence reducing wastes to protect our environment.
Prior to reusing those retired EV batteries, we need to conduct a comprehensive screening process. Through executing a series of predefined battery charge/discharge tests, we could then obtain the associated battery characteristics, such as up-to-date capacity, internal resistance, Open-Circuit Voltage (OCV) characteristics and etc. After evaluating various performance indicators, we could identify smart batteries with potentials for stationary energy storage. To safeguard the system operation, a comprehensive protection is provided, including discharge/charge over current, short circuit, over/under voltage, over/under temperature. To optimize batteries’ performance and to enhance their service life, we will incorporate several state-of-the-art technologies for monitoring as well as protection. For instance, we will adopt an active cell-balancing mechanism to achieve charge equalization amongst different batteries. To cope with deployment at faraway areas, we will introduce remote real-time battery monitoring. The battery control system will regularly transmit the latest battery status data to a dedicated server wirelessly, which will conduct Artificial Intelligence (AI) optimization for various control parameters. The computation results will be transmitted back to the battery system to tweak relevant control and parameters estimation. Finally, we need to accommodate extreme operating temperature (-40°C ~ +55°C) and adverse weather conditions. We will seal the battery pack by using a type of phase change material, which will effectively absorb and dissipate the heat generated by batteries. In addition, we will also incorporate thermoelectric modules to further attain either heating or cooling purpose.