Key Takeaways & Executive Findings
- •• A novel polymer–inorganic hybrid photoelectrode (PPy@N-TiO2/CC) with a Z-scheme heterostructure was first constructed for high-efficiency photo-assisted lithium–sulfur battery (PALSB). • PPy@N-TiO2/CC acts as both a photocatalyst and an electrocatalyst, accelerating sulfur redox reactions and intermediate polysulfide conversion. • The PALSB achieves an ultrahigh discharge capacity of 1653 mAh g−1 (98.7% of theoretical) and dual-mode energy harvesting: 5 h of photo-charging delivers 333 mAh g−1. • This work integrates solar energy conversion and storage within a rechargeable battery, offering a sustainable strategy for next-generation energy storage.
Abstract
Photo-assisted lithium–sulfur batteries (PALSBs) offer an eco-friendly solution to address the issue of sluggish reaction kinetics of conventional LSBs. However, designing an efficient photoelectrode for practical implementation remains a significant challenge. Herein, we construct a free-standing polymer–inorganic hybrid photoelectrode with a direct Z-scheme heterostructure to develop high-efficiency PALSBs. Specifically, polypyrrole (PPy) is in situ vapor-phase polymerized on the surface of N-doped TiO2 nanorods supported on carbon cloth (N-TiO2/CC), thereby forming a well-defined p–n heterojunction. This architecture efficiently facilitates the carrier separation of photo-generated electron–hole pairs and significantly enhances carrier transport by creating a built-in electric field. Thus, the PPy@N-TiO2/CC can simultaneously act as a photocatalyst and an electrocatalyst to accelerate the reduction and evolution of sulfur, enabling ultrafast sulfur redox dynamics, as convincingly validated by both theoretical simulations and experimental results. Consequently, the PPy@N-TiO2/CC PALSB achieves a high discharge capacity of 1653 mAh g−1, reaching 98.7% of the theoretical value. Furthermore, 5 h of photo-charging without external voltage enables the PALSB to deliver a discharge capacity of 333 mAh g−1, achieving dual-mode energy harvesting capabilities. This work successfully integrates solar energy conversion and storage within a rechargeable battery system, providing a promising strategy for sustainable energy storage technologies.
1. Introduction
The depletion of resources and environmental pollution urge us to develop recyclable clean energy rapidly. Among various rechargeable batteries, the lithium–sulfur battery (LSB) is an ideal candidate for next-generation energy storage system owing to its high theoretical energy density (2600 Wh kg−1). However, there is still a significant gap between the actual performance of LSBs and the theoretical potential, primarily due to the sluggish/incomplete conversion of sulfur and its discharge intermediates, lithium polysulfides (Li2Sx, 4 ≤ x ≤ 8).
Fortunately, the conversion of polysulfide can be effectively promoted by introducing physical fields (such as optical fields, magnetic fields, and sound fields). Optical fields accelerate the liquid-to-solid conversion kinetics of polysulfides through photocatalytic effect, a magnetic field can optimize the mass transfer process of polysulfide through Lorentz force, while ultrasonic cavitation can significantly reduce the activation energy of polysulfide conversion. Notably, the photo-assisted strategy can not only photoelectric co-catalyze the conversion of polysulfides, but also convert solar energy into chemical energy in a single device, exhibiting promising application prospects. The design of an effective photocathode for capturing solar energy and storing it in LSBs allows photo-generated carriers to enhance the electrochemical reaction and reduce electric energy consumption, thereby facilitating the integration of solar energy storage and conversion within LSBs. However, designing an effective photoelectrode remains a significant challenge.
Research on photo-assisted lithium–sulfur batteries (PALSBs) is still in its infancy. Up to now, only a few materials have been explored that qualified for constructing photoelectrodes for PALSBs. In 2015, a CdS/Pt photocathode was fabricated to assemble PALSB, which achieved a capacity of 792 mAh g−1 after 2 h light irradiation, confirming the great potential of integrating solar energy with LSBs. Subsequently, CdS-Ti...
Loading authentic research manuscript (Pages 1–5)...
Fei Zhao, Yibo He, Xuhong Li, Ke Yang, Shuo Chen, Yuanzhi Jiang, Xue-Sen Wang, Chunyuan Song, Xuqing Liu (2026). Ultrafast Sulfur Redox Dynamics Enabled by a PPy@N-TiO2 Z-Scheme Heterojunction Photoelectrode for Photo-Assisted Lithium–Sulfur Batteries. Nano-Micro Letters. https://doi.org/10.1007/s40820-025-01946-3
Research & Educational Purpose Only:The translations, structured abstracts, analytical annotations, and data reports provided by SinoTechIntel are intended exclusively for academic research, internal corporate R&D, and educational benchmarking. They do not constitute formal engineering, chemical safety, legal, or professional advice.
Copyright & Intellectual Property Notice: Original copyright of the underlying source articles and experimental data remains with the respective authors, institutions, and original publishing journals. SinoTechIntel claims intellectual property only over its proprietary translations, analytical syntheses, and AEO structured enhancements in accordance with international fair use and academic citation principles.
Frequently Asked Questions
What is a photo-assisted lithium–sulfur battery (PALSB)?
A PALSB integrates solar energy harvesting with lithium–sulfur battery chemistry, using a photoelectrode to capture light and enhance sulfur redox reactions, thereby improving performance and enabling solar-to-chemical energy conversion.
How does the PPy@N-TiO2 Z-scheme heterojunction improve battery performance?
The Z-scheme heterostructure creates a built-in electric field that enhances charge carrier separation and transport, while PPy and N-TiO2 act as both photocatalyst and electrocatalyst, accelerating sulfur reduction and polysulfide conversion, leading to ultrafast redox dynamics and high capacity.
What are the key performance metrics of the developed PALSB?
The PALSB achieves a discharge capacity of 1653 mAh g−1 (98.7% of theoretical) and can deliver 333 mAh g−1 after 5 hours of photo-charging without external voltage, demonstrating dual-mode energy harvesting.
What is the significance of this work for sustainable energy storage?
This work successfully integrates solar energy conversion and storage within a rechargeable battery system, offering a promising strategy for sustainable and eco-friendly energy storage technologies.
What materials are used in the photoelectrode?
The photoelectrode is a free-standing polymer–inorganic hybrid consisting of polypyrrole (PPy) polymerized on N-doped TiO2 nanorods supported on carbon cloth (N-TiO2/CC), forming a p–n heterojunction with Z-scheme structure.
Related Technical Papers & Translations
Direct Repair of the Crystal Structure and Coating Surface of Spent LiFePO4 Materials Enables Superfast Li-Ion Migration
The rapid accumulation of spent LiFePO4 (LFP) cathodes from retired lithium-ion batteries necessitates the development of effective and environmental-friendly recycling strategies. In this context, direct regeneration has emerged as a promising approach for reclaiming LFP cathode materials, offering a streamlined pathway to restore their electrochemical functionality. We report an integrated regeneration protocol that simultaneously repairs the degraded crystal structure and reconstructs the damaged carbon coating in spent LFP. The regenerated cathode material had superfast lithium-ion diffusion kinetics and a stable cathode–electrolyte interface, giving a remarkable rate capability with specific capacities of 122 mAh g−1 at 5C and 106 mAh g−1 at 10C (1C = 170 mA g−1). It also maintained capacities of 110.7 mAh g−1 (5C) and 84.1 mAh g−1 (10C) after 400 cycles. It could be used in harsh environments and could be stably cycled at subzero temperatures (−10 and −20 °C) and in solid-state electrolyte batteries. Life cycle assessment combined with economic evaluation using the EverBatt model reveals that this direct regeneration approach has high economic and environmental benefits.
Oxide Semiconductor for Advanced Memory Architectures: Atomic Layer Deposition, Key Requirement and Challenges
Oxide semiconductors (OSs), introduced by the Hosono group in the early 2000s, have evolved from display backplane materials to promising candidates for advanced memory and logic devices. The exceptionally low leakage current of OSs and compatibility with three-dimensional (3D) architectures have recently sparked renewed interest in their use in semiconductor applications. This review begins by exploring the unique material properties of OSs, which fundamentally originate from their distinct electronic band structure. Subsequently, we focus on atomic layer deposition (ALD), a core technique for growing excellent OS films, covering both basic and advanced processes compatible with 3D scaling. The basic surface reaction mechanisms—adsorption and reaction—and their roles in film growth are introduced. Furthermore, material design strategies, such as cation selection, crystallinity control, anion doping, and heterostructure engineering, are discussed. We also highlight challenges in memory applications, including contact resistance, hydrogen instability, and lack of p-type materials, and discuss the feasibility of ALD-grown OSs as potential solutions. Lastly, we provide an outlook on the role of ALD-grown OSs in memory technologies. This review bridges material fundamentals and device-level requirements, offering a comprehensive perspective on the potential of ALD-driven OSs for next-generation semiconductor memory devices.
Laser powder bed fusion of biodegradable Zn-4Cu alloy: Processing, microstructure and properties
Zn's natural degradability and biocompatibility make it a promising candidate for implants, however, its mechanical properties remain insufficient for bone applications. In this study, the performance of Zn was enhanced by developing Zn-Cu alloys via laser powder bed fusion (LPBF). Optimal LPBF parameters for forming stable tracks were achieved by adjusting laser power and scanning speed. Under optimized conditions of 100 W and 100 mm/s, high-density (99.58%) Zn-Cu alloys with improved hardness (68.2HV) and yield strength (160 MPa) were achieved. These improvements are attributed to solid solution strengthening, segregation strengthening, and grain refinement. The Zn-Cu alloys also demonstrated favorable degradation behavior, with a rate of 0.16 mm/year. This degradation is primarily driven by micro-galvanic corrosion between the CuZn5 phase and Zn matrix, along with refined grains and increased grain boundary density. This work demonstrates a viable strategy for fabricating Zn-based implants with enhanced structural integrity and mechanical performance via LPBF.