January-February 2025 Import Data for Nutshell Charcoal Released, A Brief Discussion on the Application and Development of Coconut Shell Charcoal in the Sodium-Ion Battery Field

The application scenarios for imported nut shell charcoal in China are quite broad, including industrial adsorption and purification, water treatment, soil improvement, and as a hard carbon anode in sodium-ion battery cells. Among these, coconut shell charcoal is the most widely used biomass material in sodium-ion battery hard carbon anodes. The main production areas for coconut shell charcoal are concentrated in tropical regions such as Southeast Asia and South Asia, including countries like Indonesia, Sri Lanka, and the Philippines. These regions' abundant coconut resources provide sufficient raw materials for coconut shell charcoal production. As one of the major importers of coconut shell charcoal, China has diverse import channels. On one hand, it secures stable supply by directly signing procurement contracts with local producers; on the other hand, it leverages the resources of international traders to obtain coconut shell charcoal products of different qualities and specifications. In the field of sodium-ion batteries, domestically produced Hainan coconuts are rarely used. From the perspective of raw material characteristics, there are differences in composition and structure between Hainan coconut shells and imported coconut shells. The unique environment in which Hainan coconuts grow, including the soil and climate, affects the properties of the coconut shells. Research shows that the proportions of lignin and cellulose in domestically produced Hainan coconut shells differ from those in imported coconut shells. For example, the lignin and cellulose content in imported coconut shells is relatively stable, which is beneficial for preparing coconut shell charcoal with well-developed and uniform pore structures. However, due to the variability in growth environments, the components of Hainan coconut shells fluctuate, making it difficult to precisely control their microstructure during the conversion process. This results in an inability to ensure ideal transmission channels for sodium ions, thereby affecting the C-rate performance of the battery. Currently, the coconut shell charcoal used in hard carbon anodes is mainly imported, and this material is significantly influenced by climate and production supply.

The advantages of coconut shell charcoal in sodium-ion battery applications are as follows:

Unique Pore Structure

Coconut shell-based hard carbon has a well-developed pore structure, which is crucial for enhancing the performance of sodium-ion batteries. During the charging and discharging process, the abundant pores facilitate the penetration of the electrolyte, allowing sodium ions to be transmitted more quickly between the electrode material and the electrolyte, thus improving the C-rate performance of the battery.

Suitable Chemical Composition

Coconut shell charcoal has low ash content and a suitable H/C and O/C ratio, making it an ideal anode material for sodium-ion batteries. The low ash content means fewer impurities, reducing side reactions within the battery and improving its stability and cycle life. An appropriate H/C and O/C ratio helps optimize the electronic structure of the carbon material, enhancing its adsorption and desorption capabilities for sodium ions, thereby improving the battery's charge and discharge performance.

High Cost-Effectiveness

Compared to some other anode materials for sodium-ion batteries, coconut shell charcoal has significant cost advantages. First, coconut shells, as the raw material for coconut shell charcoal, are widely available and relatively inexpensive. Global annual coconut shell production exceeds 20 million mt, with the current utilization rate being less than 30%, providing a rich and low-cost raw material reserve for the coconut shell charcoal industry. Second, the preparation process for coconut shell charcoal is relatively simple, requiring no complex equipment or high energy consumption, further reducing production costs.

As the market for sodium-ion batteries continues to expand, the demand for coconut shell charcoal will continue to grow. To ensure a stable supply of raw materials, companies will gradually diversify their sources. In the short term, biomass will still be dominated by coconut shells, but in the long run, shell-based raw materials may not meet market demand. Other biomass materials, such as bamboo, straw, and reeds, can serve as alternative or supplementary raw materials to coconut shells.

Coconut shell charcoal, with its advantages in import trade and unique performance in sodium-ion batteries, is becoming an important component in the field of hard carbon anode materials for sodium-ion batteries. In the future, with the advancement of technological innovation, raw material diversification, and market expansion, sodium-ion batteries will play a more critical role, contributing to global sustainable energy development.