Reduced Battery Capacity Research Articles

PV-fed multi-output buck converter-based renewable energy storage system with extended current control for lifetime extension of Li-ion batteries

Recently, there has been a visible intensification of research on increasing the cycle life of energy storage devices used in Photovoltaic (PV)-fed energy storage systems (ESS). Compared to existing battery technologies, Lithium-ion (Li-ion) batteries have advantages such as high energy density and high cycle life. However, many existing Hybrid energy storage system (HESS) suffers from the fact that Li-ion batteries have limited cycle life, calendar and cycle aging. Therefore, attention has shifted towards the charging techniques necessary to improve the service life of Li-ion batteries by increasing their cycle life and reducing capacity losses. One such approach is to charge the battery by gradually increasing it from a certain level, rather than starting the charging process directly with the maximum charging current. This study proposes Extended Current Control (ECC) to reduce battery capacity losses and extend service life in PV-fed HESSs. The maximum power point (MPP) of the PV module is provided by the Perturb and observe (P&O) algorithm via the supercapacitor (SC) converter, while ECC is performed via the battery converter. This approach requires less hardware, unlike optimization, rule, or filtering based techniques. Controlling the battery current over a large area protects the battery packs from high currents at the start of charge and reduces capacity losses by increasing cycle life. Compared to PV-fed ESS containing only battery packs, the proposed technique provides a 40 % improvement in battery charging current, an 8 % improvement in the converter duty ratio in reaching the MPP point, and a 31.69 % improvement in battery capacity fades.

Assembling Zn2+ on surface of kevlar NanoFibers as functionalized separator for dendrite-free Zn anode and high-performance Zn metal batteries

The proliferation of wearable electronic products has made the development of flexible energy storage devices increasingly important. Among various options, aqueous Zn metal batteries are promising due to their low cost, safety, non-toxicity, environmental friendliness, and abundant element storage. However, the growth of dendrites on the anode surface of Zn metal batteries is a significant challenge to efficient transport of Zn2+, which leads to reduced battery capacity or even failure. This limitation hinders practical applications for these batteries. This study develops a functionalized separator with high ion transport performance and excellent mechanical performances by electrostatic assembling deprotonated PPTA− molecular chains with Zn2+ using Kevlar as a raw material. The successful assembly of Zn2+ is confirmed through chemical composition and functional group analysis. The prepared separator significantly shows the increased the transfer number of Zn2+ and decreased activation energy of Zn2+ deposition. The separator is used in Zn||Zn symmetric batteries, achieving a reversible deposition/stripping process of more than 180 h at a current density of 1 mA cm−2 and a deposition capacity of 1 mAh·cm−2. When applied to Zn||MnO2 batteries, an initial discharging specific capacity of up to 220 mAh·g−1 is obtained at a high current density of 2 A g−1, and the battery could be cycled stably for more than 1, 200 cycles, with a smooth and flat Zn anode surface and no obvious dendrite growth. The separator has good potential for flexible energy storage applications due to its excellent mechanical strength, which enables it to maintain high electrochemical activity even after bending 500 times at 180°. Overall, the functionalized separator effectively inhibits dendrite growth, improves the electrochemical stability of Zn metal batteries, and demonstrates significant application potential for other flexible energy storage applications.

Analysis of the limitation factors of thick cathodes based on experimental and P2D model simulations

Abstract The thickness of the electrode significantly impacts battery performance. Increasing electrode thickness contributes to higher energy density, but it also leads to a decline in rate capability and stability. Therefore, a balance must be struck when determining electrode thickness. In this context, we compare experimental results with numerical simulations to reveal the primary reasons behind the drastic reduction in battery capacity and rate performance due to excessively thick electrodes. At the same time, there is minimal difference between experimental and simulated results at lower electrode thicknesses and smaller currents. As the electrode thickness and current increase, experimental performance deteriorates more rapidly, which arises from the uneven distribution of various components within the cathode during the drying process. In addition, we also simulated the capacity of the crack-free electrode and the depth of discharge at various locations within it, thus determining the main factors of its capacity decline.

Optimizing the photovoltaic-assisted electric bus network with rooftop energy supply

As a clean and renewable resource, solar energy has demonstrated its potential to alleviate the energy vulnerability and grid strain for electric bus systems. In this study, we investigate the optimal design of an electric bus network in which rooftop solar panels are equipped to provide en-route photovoltaic assistance. A continuous-based model is proposed to optimize critical network design variables, including time-varying headway, stop spacing, and deployment of depot chargers. Introducing rooftop solar photovoltaics can significantly reduce range anxiety for electric buses. Compared with conventional electric bus systems, 4.2%–7.8 % daily in-operation time can be extended, while at most 5.7 % fleet size can also be saved per day. The proposed system demonstrates much more advantages in regions where hourly solar irradiance exceeds 1000 W/m2. Sensitivity tests indicate that (1) with a 10 % improvement in energy conversion efficiency, 1.2 % daily fleet size and 7.5 % depot chargers can be reduced; (2) every 50-kWh increase in bus battery capacity would bring a 1.8 % increment in system cost. Increasing the installation area of solar panels can help reduce battery capacity and lower the system cost. A real-world-based case in Panjin City, China is further designed to validate the application of the proposed system.

Substitution of a Microstructure-Simulation with a Data-Driven Approach for Modelling Mechanical Degradation of Electrodes

One significant aspect of battery aging involves the mechanical degradation of battery electrodes. The intercalation of ions into the active material particles of a lithium-ion battery creates a concentration profile along the radial direction of the active material particle, influenced by transport properties and kinetics. Mechanical stresses arise due to the spatial constraints of intercalated ions, leading to the mechanical degradation of the electrode.Common cathode materials used in practical applications, such as Lithium Nickel Manganese Cobalt Oxide (NMC) or Lithium Iron Phosphate (LFP), undergo a transition from a lithium-poor phase to a lithium-rich phase during the intercalation process. Along this phase boundary, high mechanical stresses occur due to the inconsistency of the concentration profile, resulting in particle fractures. This can lead to electrical isolation and, consequently, the electrochemical inertization of the active particle material, manifested as a reduced battery capacity on a macroscopic scale.Simulating these processes poses computational challenges. Given current computational power, accurately simulating a sufficient number of cycles for a microstructure simulation, which describes transport processes within a battery, is computationally prohibitive. Therefore, this study employs data-driven models. To predict radial concentration profiles within the particle, a physics-informed neural network (PINN) proves useful by extending the cost function with the transport equation. Classical neural networks (ANN) are utilized to calculate the electrical voltage of active material particles. These models are trained with results from microstructure simulations to develop a grey-box model, enabling the inclusion of mechanical degradation in the electrode simulation.Mechanical stresses and degradations are thus investigated under various galvanostatic discharge rates to define an aging-resistant operational window for the battery.

Unraveling the Degradation Mechanisms of Lithium-Ion Batteries

Lithium-Ion Batteries (LIBs) usually present several degradation processes, which include their complex Solid-Electrolyte Interphase (SEI) formation process, which can result in mechanical, thermal, and chemical failures. The SEI layer is a protective layer that forms on the anode surface. The SEI layer allows the movement of lithium ions while blocking electrons, which is necessary to prevent short circuits in the battery and ensure safe operation. However, the SEI formation mechanisms reduce battery capacity and power as they consume electrolyte species, resulting in irreversible material loss. Furthermore, it is important to understand the degradation reactions of the LIBs used in Electric Vehicles (EVs), aiming to establish the battery lifespan, predict and minimise material losses, and establish an adequate time for replacement. Moreover, LIBs applied in EVs suffer from two main categories of degradation, which are, specifically, calendar degradation and cycling degradation. There are several studies about battery degradation available in the literature, including different degradation phenomena, but the degradation mechanisms of large-format LIBs have rarely been investigated. Therefore, this review aims to present a systematic review of the existing literature about LIB degradation, providing insight into the complex parameters that affect battery degradation mechanisms. Furthermore, this review has investigated the influence of time, C-rate, depth of discharge, working voltage window, thermal and mechanical stresses, and side reactions in the degradation of LIBs.

Method of Compensating Overhead Catenary Line Voltage for Reduction of Battery Capacity at Substation Replacement by Wayside Energy Storage System

Method of Compensating Overhead Catenary Line Voltage for Reduction of Battery Capacity at Substation Replacement by Wayside Energy Storage System

Exploring the key technologies needed for the commercialization of electric flying cars: A levelized cost and profitability analysis

Flying cars, also known as Vertical Takeoff and Landing aircraft (VTOLs), can significantly improve transportation efficiency, and are expected to play an important role in future transportation. However, the technical requirements to make electric flying cars economically feasible remains insufficiently investigated. In this study, with detailed cost calculation model, the levelized cost and profit of electric flying car operation are estimated. The results show that under the base case (250 Wh/kg battery, baseline cost, battery swapping, no unmanned autonomous driving systems), the levelized cost is $0.61/passenger-km, about one-third higher than on-road taxi cost. Under passenger fare of $1.00/passenger-km, the net present value is $0.46 million, which implies an investment return cycle of 5 years, comparable to the airline industry. Advanced technology deployment can significantly improve profitability. With battery specific energy increased to 400 and 600 Wh/kg, the net present value increases by 60 % and 72 %. The investment return cycle can be reduced to 3 and 2 years, making electric flying car operation a high-profitability industry comparable to ride-sharing. The use of unmanned autonomous driving systems can drive net present value up to 4.2 times that under the base case, implying an investment return cycle of 2 years. Compared with battery swapping, charging as the energy supplementing approach leads to lower operation efficiency, but can be compensated by fast-charging and the reduction of battery capacity. The results suggest that the electric flying car industry could take full advantage of on-road-vehicle battery technology development. Efforts should be made in establishing a complete air-ground joint management system to facilitate unmanned autonomous driving.

A technique for separating the impact of cycle aging and temperature on Li-ion battery capacity

Reduction of battery capacity is a well-known symptom of aging, making it a universally accepted indicator of the state of health. Capacity also significantly depends on temperature, therefore, separating the effect of temperature from that due to aging has utmost important for a proper state of health assessment. However, according to the latest literature, there is a lack of information about how the temperature dependency of capacity changes with battery aging. In this respect, the study presented in this paper is based on an experimental campaign aimed at measuring battery capacity at different temperatures and cycling levels. Starting from the obtained results, an analytical model describing how the variation law of battery capacity with temperature is affected by cycling was proposed and validated. The achieved accuracy is better than 0.6 % for all the considered operating conditions.

Interface synergistic stabilization of zinc anodes via polyacrylic acid doped polyvinyl alcohol ultra-thin coating

Aqueous batteries have been considered as an alternative to lithium-ion batteries due to their advantages such as high energy density and high safety. Aqueous zinc ion batteries (ZIBs) have attracted particular attention due to the high capacity, low cost and low redox potential of zinc metal. However, zinc metal anodes suffer from problems such as dendrite growth, hydrogen evolution reaction (HER), and surface corrosion, which can lead to unfavorable effects, including reduced battery capacity and shorter cycle life. Herein, we constructed a PVA@PAA protective layer on the zinc anode surface by combining polyvinyl alcohol (PVA) with polyacrylic acid (PAA). This protective layer not only physically inhibits the growth of dendrites but also suppresses HER and surface corrosion via isolation of the electrolyte from the zinc anode. Furthermore, theoretical calculations indicate that PAA enhances the reactivity of PVA, increasing zinc ion transport rates and improving ionic conductivity. With the above synergistic effects, the symmetric batteries could achieve an ultra-long stable cycling of 2400 h at 3 mA·cm−2. Furthermore, this research lays the technical groundwork for the expanded applications of ZIBs on a larger scale.

Novel Binder with Cross-Linking Reconfiguration Functionality for Silicon Anodes of Lithium-Ion Batteries.

Silicon is expected to be used as a high theoretical capacity anode material in lithium-ion batteries with high energy densities. However, the huge volume change incurred when silicon de-embeds lithium ions, leading to destruction of the electrode structure and a rapid reduction in battery capacity. Although binders play a key role in maintaining the stability of the electrode structure, commonly used binders cannot withstand the large volume expansion of the silicon. To alleviate this problem, we propose a PGC cross-linking reconfiguration binder based on poly(acrylic acid) (PAA), gelatin (GN), and β-cyclodextrin (β-CD). Within PGC, PAA supports the main chain and provides a large number of carboxyl groups (-COOH), GN provides rich carboxyl and amide groups that can form a cross-linking network with PAA, and β-CD offers rich hydroxyl groups and a cone-shaped hollow ring structure that can alleviate stress accumulation in the polymer chain by forming a new dynamic cross-linking coordination conformation during stretching. In the half cell, the silicon negative prepared by the PGC binder exhibited a high specific capacity and capacity maintenance ratio, and the specific capacity of the silicon negative electrode prepared by the PGC binder is still 1809 mAh g-1 and the capacity maintenance ratio is 73.76% following 200 cycles at 2 A g-1 current density, indicating that PGC sufficiently maintains the silicon negative structure during the battery cycle. The PGC binder has a simple preparation method and good capacity retention ability, making it a potential reference for the further development of silicon negative electrodes.

Improved electrochemical performance of fast-charging Li-S batteries with constant power transfer protocol

Reducing the time required to replenish depleted energy in batteries stands as a crucial milestone to propel further advancements in electric vehicles and related applications. Traditional charging procedures pose notable challenges, particularly the reduction in battery capacity observed at higher current levels. In the pursuit of novel rapid protocols, certain approaches have been devised and implemented. However, their feasibility, practicality, and specific technological advantages remain unclear. In this study, we conduct a comparative analysis, for the first time, of the electrochemical performance of promising lithium‑sulfur batteries. We assess the use of an unconventional fast charging protocol involving constant power transfer against the outcomes derived from employing the conventional constant current protocol under similar conditions. The constant power charging protocol proves highly effective for rapid charging rates (ranging from 1C to 4C), resulting in over a 10 % reduction in charging duration compared to the conventional CC protocol. Additionally, it significantly decreases overall degradation per cycle by up to 46.67 % and noticeably enhances cell lifespan, all while maintaining the same energy consumption during the charging process. The observed differences in behavior provide valuable insights into the mechanisms through which the constant power protocol enhances electrochemical performance.

(Invited) Electrochemical and Postmortem Analyses of 18650-Type Li-Ion Secondary Battery Degraded at High and Low Temperature Environments

Lithium-ion secondary batteries have been widely used as small-size and lightweight energy sources for applications of laptops, robots and electric vehicles. For realizing a high performance, the energy sources are required to have high energy density with high reliability. The batteries are charged and discharged repeatedly based on anode and cathode reactions, which both accompany side reactions to a greater or less extent. The battery degradation phenomena are well explained by kinetics of chemical reactions evaluated by non-destructive examination.1 To understand the battery degradation mechanism for developing a durable one, it is indispensable to clarify the side reactions occurred to cause the degradation. For that purpose, differential capacity curves (dQ/dV vs. V) and electrochemical impedance spectroscopy (EIS) were employed as electrochemical measurements.2 To support the mechanism estimated by the measurements, postmortem analyses were conducted using SEM, XPS and XRD. These investigations were performed to the commercially available 18650 cell consisting of Li(Ni, M)O2 (M: metal elements to partially replace Ni) as the cathode material and graphite as the anode material. The employed loads were calendar deterioration and charge/discharge cycle deterioration.3,4 Firstly, the calendar deterioration behavior of the 18650-type battery was evaluated by storing them at 80 °C for different durations. The results indicate that the battery capacity decreased with the increasing number of storage days in a high-temperature environment. From the differential capacity curves, we found that the change in the overvoltage, which was caused by the electrode reaction, that appeared at approximately 4.2 V was most significant. To analyze this phenomenon, EIS of the deteriorated battery was measured at 4.2 V, and it was confirmed that the cathode-based resistance of the battery increased significantly at this potential. Furthermore, postmortem analysis revealed that the cathode active material of the tested batteries clearly deteriorated; however, no significant change in the active material in the anode was observed. Therefore, it is considered that the cathode materials of nickel-based lithium-ion secondary batteries deteriorate by storing at 80 °C, thereby resulting in reduced battery capacity and increased cathode component resistance after storing at high temperatures.Secondly, cycle deterioration behaviors of the lithium-ion batteries in different operating temperature were studied. Compared with the deterioration in the high-temperature range, the degree of decrease in battery capacity at the low temperature was greater, and the more severe the deterioration was shown at temperatures far from the safe temperature range. From the differential capacity analysis, the peaks corresponding to the anode was significantly reduced at the voltage of the initial charging stage after cycle deterioration at low temperature. This means that the lithium ions intercalated into/deintercalated from the graphite layer decreased. In addition, EIS of the batteries before and after cycle deterioration was measured at each deteriorated temperature. Based on these, postmortem analysis was conducted with a major focus on the anode after 20-cycle deterioration at low temperature. From the SEM observation, the anode can be known to grow thicker with generating cracks and gas pockets. According to the XPS measurements, it is found that Li2CO3 and LiF are generated by decomposition of electrolytic solution at the anode surface.Overall, it was clarified that the deterioration at high temperature affected the cathode and that at low temperature affected the anode.

N-doped EG@MOFs derived porous carbon composite phase change materials for thermal optimization of Li-ion batteries at low temperature

Electric vehicles often encounter the challenge of battery capacity reduction in cold environments. Existing thermal conductive patches and partial short-circuiting for electrical heating can address the above issues. In this paper, a method to increase battery capacity was proposed by phase change material (PCM) assisted heating. Specifically, a nitrogen-doped hierarchical porous carbon (NPC) was synthesized through a combination of “low-temperature calcination + concentrated nitric acid treatment” to treat the chrysanthemum-shaped MOF-199@EG, and impregnated with stearic acid (SA) to form a stable composite PCM. With its well-developed pore structure and N-adsorbed active sites, the NPC prevents the leakage of molten SA, maintains stability effect and significantly improves the thermal properties of SA composites. The SA/NPC has a loading rate of 80.15 wt%, closely approaching the theoretical values of latent heat (137.89 J·g-1). It also demonstrates enhanced thermal conductivity (1.873 W·m-1·K-1) and thermal diffusivity (1.024 mm2·s-1). Thermal conductivity and thermal diffusivity of SA/NPC are 8.56 times and 14.06 times higher, respectively, than those of SA. Furthermore, when the lithium-ion battery is discharged 2C at −20 °C, the utilization of SA/NPC as an insulation material can increase the discharge energy by 7.89 %. Consequently, this novel composite PCM holds significant promise for the thermal optimization of batteries at low temperature.

Optimization of configurations and scheduling of shared hybrid electric‑hydrogen energy storages supporting to multi-microgrid system

As the energy structure undergoes transformation and the sharing economy advances, hydrogen energy and shared energy storage will become the new norm for addressing future energy demand and user-side storage applications, in order to better meet the flexibility and sustainability requirements of the energy system. This paper focuses on shared energy storage that links multiple microgrids and proposes a bi-layer optimization configuration method based on a shared hybrid electric‑hydrogen storage station for microgrids, combining cooling, heating, and power systems, to better achieve efficient energy utilization and promote sustainable development. The upper-layer model solves the energy storage station capacity configuration problem, while the lower-layer model solves the optimization operation problem of the multi-microgrid system. The lower-layer model is transformed into a constraint condition of the upper-layer model based on the Karush-Kuhn-Tucher condition of the lower-layer optimization model, and the Big-M method is used to linearize nonlinear problems. The rationality and effectiveness of the proposed bi-layer planning model are verified through analytical examples in three different scenarios. The results showed that compared to individual energy storage, shared power storage achieved an average daily net income of $430.00, reduced battery capacity by 75.94 %, and reduced daily operating costs of the microgrids by 11.53 %. Hybrid energy storage increased the daily net income of the energy storage side by 61.67 %, further reduced battery capacity by 67.13 %, and further reduced daily operating costs of the microgrid by 3.39 %. In addition, the optimal capacity allocation of energy storage systems and the operation optimization of multi microgrid systems have been achieved. The results demonstrate that the proposed hybrid energy storage services can effectively reduce user costs, save energy storage resources, and achieve mutual benefits for both users and energy storage operators.

The effect of battery charging method on reducing battery capacity in off-grid solar home systems

Due to the widespread use of lithium batteries in the off-grid solar home systems (SHS), to reduce system costs, it is necessary to accurately determine the required battery capacity instead of choosing a larger battery capacity, as well as ways to increase battery life. For the first time in this paper, instead of a fixed depth of discharge battery, the effect of different depths of discharges battery, that occurs during the day and night, as well as the possible and optimal battery charging method to reduce the required battery capacity in a real off-grid SHS have been investigated. It has been shown that with this method, it is possible to use a battery with a lower capacity than the usual selection method. Moreover, the comparison of both battery charging methods shows that the pulse charging method has a significant performance in increasing the battery life and thus reducing the required battery capacity.

Can retired lithium-ion batteries be a game changer in fast charging stations?

As the global popularity of electric vehicles (EVs) continues to grow, the demand for EV batteries has significantly increased. Unfortunately, when the battery state of health (SoH) reaches a certain value, the batteries may no longer meet the driving requirements of EVs, resulting in many retired batteries. Properly disposing of these batteries is a major challenge. In this paper, we will take fast charging stations (FCSs) as an example to evaluate the economic feasibility of reusing retired batteries, which is one of the most environmentally friendly methods of disposal. To make a fair comparison between fresh and retired batteries, a bi-level sizing framework is designed to determine the optimal sizes of fresh and retired batteries, as well as photovoltaic (PV) panels in FCSs, to minimize the total cost. To ensure the high fidelity of results, diverse EV travel patterns are considered to generate the charging power demand. Additionally, a dynamic battery degradation model focused on batteries that have not yet reached their turning point is developed. This model is designed to precisely quantify the gradual reduction in battery capacity. We conducted several representative case studies using real-world data, and the simulation results indicate that FCSs with fresh batteries can achieve 42.2 % cost savings compared to those without energy storage systems, while retired batteries can achieve an additional 5.41 %–11.79 % cost savings under different scenarios. These findings can be generalized that retired batteries are promising in small-scale applications due to the relatively low refurbishment cost, and a new market stream can be potentially generated in this direction.

Backup Battery Allocation and Workload Migration Against Electrical Load Shedding at Edge

In the 5G era (and the upcoming 6G), Mobile Edge Computing (MEC) has been advocated to serve the massive amount of Internet of Things (IoT) devices by base stations (BSs) and edge data centers (EDCs). Geo-distributed EDCs are generally of much smaller scales as compared to mega DCs and hence of much lower costs, but can have fast response to their users so as to satisfy the demands of real-time applications. As their reliability and availability heavily depend on the electrical power supply, most EDCs are equipped with battery groups as backup power in case of power grid load shedding or outage. In a heterogeneous geo-distributed environment, the QoS of heavily loaded EDCs however can be severely impacted by limited backup power while lightly loaded EDCs may simply waste such precious resources. Moreover, a heavily loaded EDC may suffer from deep discharge of its battery group, which will cause a significant reduction of battery capacity and lifetime. This further aggravates the aforementioned situations should load shedding/outage happen again. In this paper, we carefully analyze the workloads in EDCs and classify them into interactive workloads and batch workloads, respectively. We then develop a novel battery allocation framework with smart workload migration for EDCs, which simultaneously protects interactive workloads from being interrupted and minimizes the waiting time of batch workloads. Our extensive evaluations show that our strategies can optimize all the objectives within a limited overall cost as compared to state-of-the-art practical allocation.

Suitability of NaK alloy for the sodium or potassium metal batteries: Competition between cathode size effect and ion reaction priority effect

Sodium-potassium (NaK) alloys in a specific ratio can maintain their liquid state at room temperature, rendering them dendrite-free anodes for alkali metal batteries. Nevertheless, a controversy has arisen regarding the suitability of either sodium metal batteries (NaMBs) or potassium metal batteries (KMBs) due to the presence of dual active ions in NaK. Based on the current research, there is a contradiction regarding the feasibility of making NaK anodes suitable for NaMBs through the cathode size effect (e.g., Na3V2(PO4)3), and for KMBs due to the ion reaction priority effect of K+. In this study, Na3V2(PO4)3 (NVP) cathodes are assembled into batteries with various anodes (Na, Na-rich-NaK, NaK, K-rich-NaK, and K), to investigate the dominant role of active ions in the competing process between the cathode size effect and the ion reaction priority effect. Tests and characterization results demonstrate that the ion preference reaction spontaneously displaces Na+ with K+ in the presence of K, although the cathode size effect may restrict K+ embedding and significantly reduce battery capacity. In summary, the ion reaction priority effect dictates the reactions that render NaK anodes exclusively suitable for KMBs without altering the reaction priority of K+.

Discharging of Spent Cylindrical Lithium-Ion Batteries in Sodium Hydroxide and Sodium Chloride for a Safe Recycling Process

Battery discharging prior to size reduction is an essential treatment in spent lithium-ion battery recycling to avoid the risk of fire and explosion. The main challenge for discharging the residual charges by immersion in an electrolyte solution is corrosion because of electrolysis reactions occurring at the battery terminals. This study investigated the discharging process of 18650 cylindrical lithium-ion batteries (LiBs) in NaCl and NaOH solutions and the generation of corrosion products, with the aim of developing a safe and clean discharging system for practical applications. The results show that water electrolysis is the primary reaction during battery immersion in either NaCl or NaOH solutions. Different forms of corrosion occur in each solution. Unlike the NaCl solution, which severely corroded the positive terminal of the battery, resulting in significant amount of solid residue, build-up of fluoride ions, and chlorine gas evolution, in the NaOH solution, a darkened surface of the negative terminal was the only obvious solid product, with no solid residue in the bulk solution, while oxygen gas was evolved. The NaOH solution was found to reduce battery capacity to a residual capacity range of 0–25 mAH after immersing batteries in the solution for 20 h. This value puts the battery in a safe condition for subsequent mechanical treatment. The results indicated that NaOH creates a clean discharging system and can potentially be reused.