Qian Liu

Biomass-derived carbons hold substantial promise for sustainable electrochemical energy storage due to their low cost, wide availability, and intrinsic heteroatom- and mineral-rich nature. However, the fundamental influence of carbonization temperature on the structural evolution of non-activated biomass-derived carbons remains insufficiently understood. In this work, corn straw-derived carbon (CS) is produced without any chemical additives to isolate the intrinsic effects of carbonization temperature on its physicochemical properties. Systematic temperature variation from 600 to 1000 °C reveals pronounced changes in micro-morphology, pore development, defect density, and the ordering of the carbon matrix, all strongly governed by the inherent mineral content of corn straw. Electrochemical evaluation in alkaline electrolyte demonstrates that CS-800 delivers the highest specific capacitance of 53.8 F g⁻¹ at 1 A g⁻¹ in a three-electrode configuration and maintains favorable rate capability in a symmetric supercapacitor device. The symmetric coin-cell supercapacitor device assembled with CS-800 as the electrodes achieved an energy density of 3.64/5.8 Wh kg⁻¹ and a power density of 5200/750 W kg⁻¹, along with remarkable cycling stability over 30,000 cycles with negligible capacitance loss. Overall, this study provides mechanistic insight into temperature-driven structural evolution in non-activated biomass-derived carbons, offering a fundamental understanding that may guide the rational design and future development of sustainable carbon electrodes for electrochemical energy-storage applications.

As key components in solid-state electrolytes, lithium salts influence the electrochemical window, ionic conductivity, and ultimately the full battery’s performance. To reduce the selection time and costs while providing electric and molecular level insights into the interactions of elements and components in solid polymer electrolytes, this paper proposes a rapid screening method based on Density Functional Theory (DFT). The structure stability, electrochemical stability, and ionic conductivity of eight common inorganic and organic lithium salts were systematically investigated by analyzing five parameters: formation energy, band gap, Li⁺–anion dissociation energy, anion–PEO binding energy, and anion diffusion barriers along PEO chains. Through a comprehensive analysis of these parameters obtained from DFT, LiTFSI has been identified as the most suitable lithium salt. The electrolytes fabricated by LiTFSI exhibited better performance. This approach, characterized by its rapidness, efficiency, and low cost, provides a viable method for screening lithium salts in developing solid-state batteries.

Aqueous zinc-ion batteries (AZIBs) have become a promising and cost-effective alternative to lithium-ion batteries due to their low cost, high energy, and high safety. However, dendrite growth, hydrogen evolution reactions (HERs), and corrosion significantly restrict the performance and scalability of AZIBs. We propose the introduction of a BaTiO₃ (BTO) piezoelectric polarized coating as an interface modification strategy for ZIBs. The low surface energy of the BTO (110) crystal plane ensures its thermodynamic preference during crystal growth in experimental processes and exhibits very low reactivity toward oxidation and corrosion. Calculations of interlayer coupling mechanisms reveal a stable junction between BTO (110) and Zn (002), ensuring system stability. Furthermore, the BTO (110) coating also effectively inhibits HERs. Diffusion kinetics studies of Zn ions demonstrate that BTO effectively suppresses the dendrite growth of Zn due to its piezoelectric effect, ensuring uniform zinc deposition. Our work proposes the introduction of a piezoelectric material coating into AZIBs for interface modification, which provides an important theoretical perspective for the mechanism of inhibiting dendrite growth and side reactions in AZIBs.