Development and Assesment of Composite Battery Casing from Recycled Plastic

Development and Assesment of Composite Battery Casing from Recycled Plastic

Mr. J. Sujithkumar,

Assistant Professor, Department of Mechanical Engineering, Paavai Engineering College.

R. Mohan, K. Vasanth, R. Vijay, K. Yogesh

UG Scholar, Department of Mechanical Engineering, Paavai Engineering College.

Abstract – The growing demand for sustainable materials in energy storage applications has encouraged the use of recycled polymers in structural components. This paper presents the development and assessment of a composite battery casing fabricated from recycled plastic. The recycled plastic matrix was reinforced with suitable filler materials to improve mechanical strength and durability while maintaining lightweight characteristics. The fabricated composite casing was evaluated through mechanical testing, including tensile, flexural, and impact strength, along with thermal stability and electrical insulation performance relevant to battery safety requirements. The experimental results demonstrate that the developed composite exhibits enhanced mechanical properties compared to unreinforced recycled plastic and satisfies the essential functional requirements of battery casing applications. The proposed material offers a cost-effective and environmentally sustainable alternative to conventional battery casing materials, supporting circular economy principles and sustainable engineering practices.

Keywords Recycled plastic, composite materials, battery casing, mechanical properties, tensile behavior, impact strength, sustainable materials.

INTRODUCTION

The rapid advancement of battery technologies for applications such as electric vehicles, renewable energy storage systems, and portable electronic devices has significantly increased the demand for efficient and reliable

battery enclosures. Battery casings serve as a critical component, providing mechanical protection against external loads, safeguarding internal cells from impact and vibration, ensuring electrical insulation, and assisting in thermal management. The performance and safety of a battery system are therefore strongly influenced by the material used for its casing.

Traditionally, battery casings are manufactured using metals such as steel or aluminum, as well as virgin polymer materials. Although metallic casings offer high strength and durability, they increase overall system weight and are susceptible to corrosion. Virgin polymer casings, on the other hand, provide weight reduction and ease of manufacturing but involve higher raw material costs and contribute to environmental concerns associated with plastic production. These limitations have

driven research toward alternative materials that can meet functional requirements while supporting sustainability goals.Plastic waste generation has emerged as a major global environmental challenge. Recycling plastics reduces landfill accumulation, lowers greenhouse gas emissions, and conserves natural resources. Recycled plastics are increasingly being explored for engineering applications due to their economic and ecological benefits. However, recycled plastics generally exhibit inferior mechanical strength, impact resistance, and thermal stability compared to virgin polymers, which restricts their direct application in safety-critical components such as battery casings.

To address these challenges, composite material technology offers a promising solution. By reinforcing recycled plastic matrices with fibers or particulate fillers, the mechanical, thermal, and structural properties of the material can be significantly enhanced. Composite materials enable property customization by optimizing reinforcement type, content, and processing methods. As a result, recycled plastic-based composites have shown potential in automotive panels, structural housings, and consumer product enclosures.Despite the growing interest in sustainable composites, limited research has focused specifically on the development of battery casings using recycled plastic composites. Moreover, comprehensive assessment involving mechanical strength, impact resistance, thermal behavior, and insulation characteristics relevant to battery safety standards remains insufficient. This lack of systematic evaluation highlights a research gap in the application of recycled plastic composites for battery enclosure systems.

The present work aims to address this gap by developing a composite battery casing using recycled plastic as the base material and evaluating its performance through experimental testing. The study focuses on assessing key properties such as tensile strength, flexural strength, impact resistance, and thermal stability to determine the suitability of the developed composite for battery casing applications. The outcomes of this research contribute to sustainable material development and demonstrate the feasibility of utilizing recycled plastic-based composites as an environmentally friendly and cost-effective alternative to conventional battery casing materials.

Furthermore, life-cycle assessment has become an essential aspect of modern material engineering. Recycled plastic composites contribute to reduced energy consumption and lower greenhouse gas emissions when compared to virgin polymer or metal-based casings. Incorporating recycled materials into battery enclosure systems aligns with global sustainability initiatives and circular economy

Frameworks, promoting responsible material utilization. From a design perspective, composite battery casings allow flexibility in geometry and thickness optimization, leading to improved weight reduction without compromising structural integrity. This is particularly beneficial for electric vehicle and portable energy storage applications, where weight efficiency directly influences performance and energy efficiency. These considerations reinforce the significance of developing recycled plastic-based composite battery casings and highlight the necessity for systematic experimental assessment, which forms the primary focus of the present study

RESEARCH METHODOLOGY

The sequence of steps engaged in the research methodology for the development and assessment of composite battery casing from recycled plastic is described as follows.Step 1 involves the selection of recycled plastic materials and suitable reinforcement or filler constituents for the development of composite battery casing, based on previous research studies and application requirements. This step also includes the identification of critical design parameters such as casing geometry, wall thickness, and reinforcement percentage. A design of experiments (DOE) approach is adopted to define material combinations and process parameters for preliminary evaluation.Step 2 consists of the preparation of composite specimens as per the defined DOE. The recycled plastic is processed through cleaning, shredding, and drying, followed by composite fabrication using an appropriate molding technique. Input process parameters such as temperature, pressure, reinforcement content, and curing time are carefully controlled. The fabricated composite samples are then subjected to material characterization to evaluate mechanical, thermal, and physical properties relevant to battery casing applications.The outcomes of Step 2 provide the necessary data to proceed to Step 3, which involves the fabrication of prototype composite battery casing components using the optimized material composition. Performance assessment of the developed casing is carried out under simulated service conditions, focusing on structural integrity, thermal stability, weight reduction, and safety aspects. A comparative techno-economic and sustainability assessment is also performed against conventional battery casing materials.The final decision regarding the practical applicability and potential commercial utilization of the recycled plastic-based composite battery casing for electric vehicle and portable energy storage systems is made based on successful experimental validation and performance evaluation.

PREPARATION OF RECYCLED PLASTIC COMPOSITE BATTERY CASING

The recycled plastic was blended with selected reinforcement and filler materials in different proportions by weight, and composite samples were prepared using a molding-based fabrication technique. Based on a Taguchi L9 design of experiments, nine distinct composite samples were fabricated with varying reinforcement weight percentages (e.g., 5%, 10%, and 15%). Additives such as flame retardants and impact modifiers were maintained at fixed proportions, while the recycled plastic matrix content

was adjusted accordingly. The prepared specimens were fabricated in standardized dimensions suitable for mechanical and thermal testing. Vickers hardness testing and universal testing machines were employed to evaluate the hardness, tensile strength, and flexural performance of the prepared composite samples.

Collection and Segregation of Plastic Waste

Recycled plastic waste is collected from municipal solid waste streams, electronic waste recycling units, and industrial scrap sources. Commonly selected plastics for battery casing applications include High-Density Polyethylene (HDPE), Polypropylene (PP), and Acrylonitrile Butadiene Styrene (ABS) due to their good mechanical strength, chemical resistance, and electrical insulation properties.The collected plastic waste is manually and mechanically segregated to remove foreign materials such as metals, rubber, paper, glass, and organic residues. Proper segregation is a critical step, as contamination can significantly degrade the mechanical strength, surface quality, and thermal stability of the final composite materialenhanced structural integrity anconsistent material performance suitable for battery casing applications.

Cleaning and Drying

After segregation, the plastic waste is subjected to a thorough cleaning process to remove dust, grease, oils, and adhered impurities. Washing is carried out using water combined with mild detergents or alkaline solutions. In some cases, multiple washing cycles are employed to ensure complete removal of contaminants.The cleaned plastic is then dried using natural air drying or hot air ovens at controlled temperatures. Moisture removal is essential because residual moisture can lead to void formation, poor bonding between matrix and reinforcement, and defects during melting and molding processesWeighing and

Shredding and Size Reduction

Dried plastic materials are fed into a mechanical shredder or granulator, where they are reduced into flakes or granules of uniform size. Typically, particle sizes ranging from 5 to 10 mm are preferred for efficient melting and mixing.Uniform size reduction enhances heat transfer during melting and ensures

consistent material flow during extrusion or molding. This step also improves the dispersion of reinforcement materials during

the blending stage, leading to improved composite homogeneity.

Fig. 1 Flow-chart to demonstrate the phases involved in process composite battery casing from recycled Plastic waste

Selection and preparation of reinforcement materials

Reinforcement materials are selected based on the desired performance characteristics of the battery casing, such as impact resistance, stiffness, thermal stability, and flame retardancy. Common reinforcements include glass fibers, carbon fibers, natural fibers, and mineral fillers like silica or calcium carbonate. Before mixing, reinforcements may undergo surface treatments such as silane treatment or alkali treatment to enhance adhesion with the recycled plastic matrix. Proper preparation of reinforcement materials improves load transfer efficiency and reduces the risk of interfacial failure in the composite.

Blending and Mixing

The shredded plastic matrix and prepared reinforcement materials are blended in predetermined weight percentages. Mixing is carried out using mechanical mixers or twin-screw extruders to achieve uniform dispersion of reinforcements throughout the plastic matrix.Controlled blending parameters such as mixing speed, temperature, and duration are maintained to prevent degradation of the plastic and breakage of reinforcement fibers. Homogeneous mixing ensures consistent mechanical and thermal properties across the entire composite material.

Melting and Composite Formation

The blended mixture is heated above the melting temperature of the base plastic using extrusion or injection molding equipment. During this stage, the plastic melts and encapsulates the reinforcement materials, forming a continuous composite matrix. Proper temperature control is essential to avoid thermal degradation of recycled plastics and reinforcements. The molten composite is then converted into pellets or sheets, which serve as feedstock for the final molding of the battery casing.

Molding of Battery Casing

The prepared composite material is molded into the required battery casing geometry using compression molding or injection molding techniques. Mold design plays a crucial role in achieving dimensional accuracy,naturally or with forced air or water cooling systems.Once cooled, excess material such as flash and burrs is removed through trimming operations. Surface finishing techniques are applied if required to improve aesthetic appearance and ensure proper fitting during battery assembly.

DESIGN OF EXPERIMENTS (DOE)

The design of experiments was formulated to systematically investigate the influence of material composition and processing parameters on the mechanical and thermal performance of composite battery casing developed from recycled plastic. A structured experimental approach was adopted to minimize the number of trials while ensuring

statistically meaningful results..Testing specimen for the composite battery casing will be illustrated in Fig.2

SELECTION OF FACTORS AND LEVELS

Based on preliminary studies and literature, three key control factors were selected, each at three levels, as summarized in Table 1.

Factor A: Recycled plastic content (wt.%) Factor B: Reinforcement content (wt.%) Factor C: Processing temperature (°C)

Table 1 Three key control factors in each levels

Fig 2 Testing specimen for the composite battery casing

RESPONSE VARIABLES

The performance of the fabricated composite battery casing samples was evaluated using the following response parameters:

• Tensile strength

• Impact strength

• Sem test

Tensile strength Test

After the sample is properly made, the composite material^s tensile testing is performed by using the UTM (universal testing machine) at room temperature This the tensile test is to determine the tensile strengt Youngs modulus, and elongation at break of the recycled plastic composite and to assess its suitability for load-bearing and protective battery housing.

The stressstrain curve obtained from the test showed an initial elastic region followed by plastic deformation, it will be shown(Fig 3) . Adequate elongation before fracture indicated sufficient ductility, whic is essential to avoid sudden brittlfailure in battery casings. The testing result of elongation in the composite material is illustrated in Table(2).

Fig.3 stress-strain relationship curve from tensile test.

Fig.4 load-displacement curve obtained from the specimen.

Table.2 The tensile test results

Impact strength Test

The Izod impact test was carried out to evaluate the impact resistance of the recycled plastic composite used for battery casing applications. The energy absorbed during fracture, measured in joules represents the Izod impact value of the material, it will be illustrated in Table(3). A higher impact value indicates better toughness and resistance to sudden shock loads. The test results demonstrate the ability of the recycled plastic composite to withstand accidental impacts and vibrations in the given thickness. which is essential for ensuring the safety and durability of battery casings in practical applications.

Table.3 Izod Impact Value of the given specimen

CONCLUSION

We can infer the following conclusion from the experiments:

1. This work successfully demonstrated the development and assessment of a composite battery casing fabricated from recycled plastic, emphasizing its suitability as a sustainable alternative to conventional casing materials. The recycled plasticbased composite showed improved mechanical strength, stiffness, and impact resistance compared to unreinforced recycled polymers, meeting essential structural and safety requirements for battery enclosure applications.

2. The results indicate that with proper material selection and processing, recycled plastic composites can be effectively utilized in functional engineering components such as battery casings. Future studies may focus on enhancing thermal and fire resistance, long- term durability, and scaling up the manufacturing process for industrial implementation..

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