Deconstruction Engineering of Lignocellulosic Biomass for the Preparation of High‐performance Hard Carbon Anode Materials in Sodium‐Ion Batteries

Why It Matters

The method boosts sodium‑ion battery performance while turning waste biomass into valuable chemicals, addressing cost and sustainability pressures in energy storage markets.

Key Takeaways

• Maleic acid pretreatment removes hemicellulose, enriches lignin/cellulose
• Closed-pore size shrinks to 1.64 nm, volume rises to 0.236 cm³ g⁻¹
• Hard carbon delivers 365 mAh g⁻¹ reversible capacity
• 69% capacity retained at 5 A g⁻¹ high-rate discharge
• Xylose and furfural co‑produced, adding value to biomass feedstock

Pulse Analysis

Sodium‑ion batteries (SIBs) are emerging as a cost‑effective alternative to lithium‑ion systems, especially for grid‑scale storage where raw‑material expense dominates economics. A critical bottleneck remains the anode material, which must combine high capacity with rapid ion transport while being inexpensive to produce. Lignocellulosic biomass, abundant and cheap, offers a promising carbon source, but direct carbonization often yields suboptimal pore structures that limit sodium intercalation. Researchers are therefore exploring pretreatment strategies that can tailor the carbon architecture before pyrolysis.

The maleic‑acid hydrothermal process presented in the study selectively dissolves hemicellulose, leaving a lignin‑rich matrix that carbonizes into a hard carbon with tighter closed pores and greater pore volume. This microstructural tuning reduces the average closed‑pore diameter from 2.30 nm to 1.64 nm and raises the closed‑pore volume, facilitating more efficient sodium ion filling. Performance testing shows a reversible capacity of 365 mAh g⁻¹ and a 69% capacity retention at an aggressive 5 A g⁻¹ rate, metrics that rival or surpass many commercial hard‑carbon anodes.

Beyond electrochemical gains, the process captures xylose and furfural—high‑value platform chemicals—from the removed hemicellulose, creating a dual‑product stream that improves overall economics. Scaling this pretreatment could integrate seamlessly with existing biomass processing facilities, offering a pathway to low‑cost, high‑performance SIB anodes while simultaneously valorizing agricultural waste. As the energy sector pushes for greener, cheaper storage solutions, such integrated biomass‑to‑energy technologies are poised to play a pivotal role in the next generation of sustainable batteries.