Source-linked AI summary
PulseBat: A field-accessible dataset for second-life battery diagnostics from realistic histories using multidimensional rapid pulse test
Shengyu Tao, Guangyuan Ma, Huixiong Yang, Minyan Lu, Guodan Wei, Guangmin Zhou, Xuan Zhang
TL;DR
Voltage protection can make adjacent matched pulses unequal, accumulating SOC deviation during second-life battery tests. The protocol uses adjacent positive and negative pulses with the same intensity and planned width; the deviation is usually slight for pulses no longer than 5 s, but higher-SOC use requires attention.
Problem
Voltage protection can make adjacent positive and negative pulses unequal, causing cumulative SOC deviation across subsequent tests.
Source: §2.6 · p. 5Method
The pulse protocol uses adjacent positive and negative pulses with the same intensity and planned width.
Source: §2.6 · p. 5Results
SOC deviation is usually very slight because pulse widths are no more than 5 s.
Source: §2.6 · p. 5Takeaways & Limitations
For higher-SOC data, account for SOC deviation to avoid introducing unnecessary errors.
Source: §2.6 · p. 5Near the battery’s SOH level, voltage may exceed the protection range, and voltage-protection effects can accumulate SOC deviation across tests.
Source: §2.6 · p. 5
Abstract
from arXiv · showhide
As electric vehicles (EVs) approach the end of their operational life, their batteries retain significant economic value and present promising opportunities for second-life use and material recycling. This is particularly compelling for Global South and other underdeveloped regions, where reliable energy storage is vital to addressing critical challenges posed by weak and even nonexistent power grid and energy infrastructures. However, despite this potential, widespread adoption has been hindered by critical uncertainties surrounding the technical performance, safety, and recertification of second-life batteries. In cases where they have been redeployed, mismatches between estimated and actual performance often render batteries technically unsuitable or hazardous, turning them into liabilities for communities they were intended to benefit. This considerable misalignment exacerbates energy access disparities and undermines the broader vision of energy justice, highlighting an urgent need for robust and scalable solutions to unlock the potential. In the PulseBat Dataset, the authors tested 464 retired lithium-ion batteries, covering 3 cathode material types, 6 historical usages, 3 physical formats, and 6 capacity designs. The pulse test experiments were performed repeatedly for each second-life battery with 10 pulse width, 10 pulse magnitude, multiple state-of-charge, and state-of-health conditions, e.g., from 0.37 to 1.03. The PulseBat Dataset recorded these test conditions and the voltage response as well as the temperature signals that were subject to the injected pulse current, which could be used as a valuable data resource for critical diagnostics tasks such as state-of-charge estimation, state-of-health estimation, cathode material type identification, open-circuit voltage reconstruction, thermal management, and beyond.
1 Overview
The overview organizes the tested second-life batteries by batch, material, nominal capacity, format, history, quantity, and state of health. It defines the material and vehicle-use abbreviations and notes that SOH can exceed 1.
- The battery overview is organized by batch, material, nominal capacity, format, history, quantity, and state-of-health range.Source: §1 · p. 2
- NMC, LMO, and LFP denote three cathode materials, while HEV, BEV, and PHEV denote vehicle-use categories.Source: §1 · p. 2
- State of health can exceed 1 because of manufacturing-process inconsistencies.Source: §1 · p. 2
2 Experimental procedures
The experimental procedures calibrate battery capacity, condition batteries to selected SOC levels, and apply pulse tests across SOC ranges determined by calibrated SOH. Voltage protection can interrupt test steps, creating possible SOC deviation in later tests.
2.1 Step 1: Capacity Calibration
- Capacity calibration uses CCCV charging followed by CC discharge, with actual discharge capacity treated as the calibrated battery capacity.Source: §2.1 · p. 2
2.2 Step 2: SOC Conditioning
- SOC conditioning adjusts the battery to a target SOC, then rests it for 10 minutes before pulse injection.Source: §2.2 · p. 3
2.3 Step 3: Pulse Injection
- Pulse testing covers planned pulse widths and magnitudes, alternating positive and negative injections to cancel equivalent energy input.Source: §2.3 · p. 3
2.4 SOC Conditioning Range Determination
- The SOC conditioning range is set below the battery’s calibrated SOH; an SOH of 0.50–0.55 gives a 5%–45% range in 5% increments.Source: §2.4 · p. 4
2.5 Voltage Protection
- When pulse voltage exceeds protection limits, the current work step is terminated, and remaining steps continue without making up the lost time.Source: §2.5 · p. 5
- Voltage exceedance is mainly possible during charging; no below-protection-range cases during discharge were found in these tests.Source: §2.5 · p. 5
2.6 SOC Deviation
- Unequal charged and discharged capacities in adjacent pulses can accumulate SOC deviation across subsequent tests, though deviations are usually slight with pulse widths no longer than 5 seconds.Source: §2.6 · p. 5
- Near the battery’s SOH, pulse voltage may exceed protection limits; higher-SOC data users should account for SOC deviation to avoid unnecessary errors.Source: §2.6 · p. 5
3 Accessibility
The authors provide access to the raw data and manipulation code and ask users to cite both the earlier Nature Communications publication and this data descriptor.
- The raw data and manipulation code are accessible, and users are asked to cite the Nature Communications publication and this data descriptor when using the data.Source: §3 · p. 5