Recycling Silicon Photovoltaic Cells into Silicon Anodes for Li-ion Batteries Using 3D Printing and an Open Source Toolchain

Mottaghi, Maryam

Recycling Silicon Photovoltaic Cells into Silicon Anodes for Li-ion Batteries Using 3D Printing and an Open Source Toolchain

Files

Mottaghi_Maryam_PhD_2026_thesis.pdf (4.01 MB)

Date

2026-02-24

Authors

Mottaghi, Maryam

Abstract

With the increasing adoption of solar energy, the disposal of end-of-life photovoltaic (PV) modules has become a growing environmental concern. The crystalline silicon embedded in these modules offers significant potential as a high-capacity anode material for lithium-ion batteries. This thesis addresses the central research question of how waste silicon solar cells can be upcycled into anodes for lithium-ion batteries using an open-source, low-cost, and scalable manufacturing toolchain. The aim is to develop a sustainable pathway that integrates Open-source hardware and additive manufacturing to create battery anodes from discarded materials. To investigate this question, an Open-source toolchain was designed and validated, including an AC/off-grid photovoltaic-powered ball mill, an Open-source scientific bottle roller, and an Open-source inert-gas glove box. Silicon recovered from waste PV cells was incorporated into photocurable resin formulations and 3D printed into electrode geometries using stereolithography (SLA) technology. The printed structures were pyrolyzed to convert the polymer matrix into conductive carbon, and form silicon–carbon composite anodes. An investigation was conducted across four pyrolysis temperatures including 800, 1100, 1200, and 1400 °C, to determine their influence on structural evolution, carbon formation, and electrochemical behaviour. Among these, 1200 °C provided the optimal balance between suppressing electrochemically inactive SiC formation, enhancing carbon conductivity, and maintaining mechanical integrity. The corresponding anodes delivered 771 mAh g-1 with 61% capacity retention over 120 cycles. To further improve conductivity and mitigate silicon volume changes, carbon nanotubes (CNTs) synthesized from post-consumer plastic-waste pyrolysis were incorporated into the resin. The CNT-reinforced anodes showed enhanced electrochemical behavior and exhibited an initial discharge capacity of 862 mAh g⁻¹ with 98.88% initial Coulombic efficiency, which increased to 1,044 mAh g⁻¹ upon cycling due to improved silicon activation and electronic pathways. This thesis demonstrates that waste silicon PV cells can be transformed into functional Li-ion battery anodes through an accessible, open-source, and sustainable manufacturing approach. The results provide a proof of concept for decentralized battery fabrication, advance circular-economy strategies for PV and plastic waste and expand the role of additive manufacturing in energy-storage materials research.

Summary for Lay Audience

With the rapid expansion of solar energy, the hidden environmental challenge of managing a huge amount of discarded photovoltaic modules becomes a concern. These end-of-life panels contain valuable materials, including crystalline silicon that holds significant potential for improving lithium-ion batteries as anode material. This thesis addresses this opportunity by developing a method to upcycle waste silicon solar cells into battery anodes using an affordable, Open-source manufacturing process. To achieve this, Open-source low-cost tools, including a ball mill to grind solar cells, bottle roller to mix the ground solar cell with other materials, and a glove box to prepare the materials in an inert gas environment, were designed and built. The research involved recovering silicon from discarded panels, mixing it with a liquid resin, and 3D printing it into precise electrode structures. These printed parts were then pyrolyzed (heated at extreme temperatures), to convert the resin into a conductive carbon framework that covers the silicon. Different pyrolysis temperatures were used, and the anode structural, electrical, and electrochemical properties were tested. The study identified that processing at 1200°C created the optimal balance for battery performance. Also, for improving the battery performance carbon derived from plastic waste was included to the structure which helped reinforce the material against the physical stress of charging. This work demonstrates a viable circular economy pathway and proves that accessible, decentralized technology can successfully transform solar and plastic waste into energy storage solutions.

Keywords

3D printing, Additive manufacturing, Batteries, Recycling, Sustainability, Solar cells, Stereolithography, Silicon, Photovoltaic, Open-source, Open-source hardware