Charge and discharge profiles of repurposed LiFePO4 batteries based on the UL 1974 standard

Abstract

Owing to the popularization of electric vehicles worldwide and the development of renewable energy supply, Li-ion batteries are widely used from small-scale personal mobile products to large-scale energy storage systems. Recently, the number of retired power batteries has largely increased, causing environmental protection threats and waste of resources. Since most of the retired power batteries still possess about 80% of their initial capacity, their second use becomes a possible route to solve the emergent problem. Safety and performance are important when using these second-use repurposed batteries. Underwriters Laboratories (UL), a global safety certification company, published the standard for evaluating the safety and performance of repurposed batteries, i.e., UL 1974. In this work, the test procedures are designed according to UL 1974, and the charge and discharge profile datasets of the LiFePO4 repurposed batteries are provided. Researchers and engineers can use the characteristic curves to evaluate the quality of the repurposed batteries. Furthermore, the profile datasets can be applied in the model-based engineering of repurposed batteries, e.g., fitting the variables of an empirical model or validating the results of a theoretical model.

Decoration of graphene nanoribbons by $5d$ transition-metal elements

“…They can be repurposed once again, serving as the battery modules in the energy storage system [78][79][80][81][82]. Governments have noticed this serious problem and are prepared to launch policies to deal with the recovery and reuse of repurposing batteries [79,[83][84][85][86][87]. The discovery of graphene and more low-dimensional materials (such as 1D finite-width GNRs discussed in this work) [88,89] makes scientists believe that these materials can be potential additives in battery materials to improve battery performance and to overcome the recycling problems of Li-ion batteries.…”

Challenges in the Real-World Evaluation of Traction Batteries at the End of their First Life

“…The technical procedures for evaluating the cells are rarely published in the literature. Except for Chung, Schneider, and Zhao (Chung, 2021;Schneider et al, 2014Schneider et al, , 2009Zhao, 2017). Overall, their technical procedures can be described as follows:…”

Na-intercalation compounds and Na-ion batteries

“…In real-world applications, the design, form factor, and raw materials of the existing pack/modules/cells often vary greatly from one another, making it difficult to develop a unified technical procedure. Furthermore, information on the detailed technical procedures used is often not easily available in the open literature, except for Schneider et al, who reported the procedure to classification and reuse small cylindrical NiMH battery modules for mobile phones [176,177]; Zhao, who shared the successful experiences of some grid-oriented applications of EV Li-ion batteries in China in a comprehensive technical procedure [178]; and Chung, who announced the procedure described in UL 1974 on LFP repurposing batteries and released the related experimental dataset publicly [179]. Based on the information from these studies, a conceptual procedure for repurposing applications is summarized in five primary steps: (1) judgment of the retired battery system based on historical information, (2) disassembly of retired battery packs/modules, (3) battery performance evaluation (mechanical, electrochemical, and safety), (4) sorting, and (5) developing control and management strategies for repurposing applications.…”