【SMM Analysis】Coconut Shell Charcoal Imports Continue to Rise in Price: Are There Other "Alternatives" for Raw Materials of Hard Carbon?

According to the latest data from the General Administration of Customs, China imported 11,622.7 mt of nutshell charcoal in May 2025, down 15% MoM and 21% YoY. The average import price of nutshell charcoal in May was $593.18/mt. In March, the average import price was $549.46/mt, indicating a MoM increase in the average import price per mt of nutshell charcoal.

In the face of rising import prices for coconut shell charcoal (due to tight raw material supply caused by disasters in Southeast Asia in 2024 and sustained increases in import prices in 2025), diverse technological pathways have emerged for "alternative" materials to sodium-ion battery hard carbon anodes, primarily falling into the following three categories:

1. Biomass-based alternatives: Low cost, high supply potential

- Straw-based hard carbon

China's annual straw production exceeds 1 billion mt (2023 data for China), with a cost of only 300-600 yuan/mt, a carbon yield of approximately 20%, and a per-mt cost that is only 1/10th that of coconut shell charcoal. Theoretically, it can support 8 TWh of sodium-ion battery demand.

Through optimization of fluidized bed technology, the capacity per gram of straw-based hard carbon reaches 280-300 mAh/g, approaching that of coconut shell-based hard carbon (300 mAh/g).

- Bamboo-based hard carbon

China produces 4.5 million mt of medium-diameter bamboo annually. The cost of bamboo-based charcoal is 500-1,000 yuan/mt, with performance close to that of coconut shell charcoal (energy density of 28 Wh/kg vs. 28.11 Wh/kg for coconut shell). Additionally, bamboo has high hardness and uniform structure, resulting in more stable pores after carbonisation.

In 2025, bamboo-based hard carbon has undergone batch testing, meeting the demands of applications such as two-wheelers and energy storage systems (ESS).

- Sugar/starch-based hard carbon

Glucose and starch are hydrothermally carbonised, with particle size controlled through additive formulations.

Raw materials are widely available (e.g., corn, sweet potatoes), with better consistency than coconut shell (fewer impurities). The capacity per gram exceeds 300 mAh/g, making it suitable for high-end batteries.

A purification process is required, resulting in a slightly higher cost than straw (approximately 800-1,200 yuan/mt), but with an autonomous and controllable supply chain.

2. Resin-based hard carbon: High performance, high cost, suitable for high-end applications

- Technological advantages: Phenolic resin-based hard carbon exhibits a 30% improvement in pore structure uniformity, excellent anti-swelling performance, a capacity per gram of 350 mAh/g (superior to coconut shell), and a high retention rate after 10,000 cycles.

- The cost of resin raw materials is 3-5 times that of coconut shell, with a carbon yield of only 20%-35%. The current price is over 50,000 yuan/mt. III. Pitch-based Hard Carbon: Ultra-low Cost, Performance to be Optimized

A by-product of petroleum/coal tar pitch, with a cost of only 2,000-3,000 yuan/mt and a carbon yield of 54% (significantly higher than biomass).

High costs for impurity removal at the front end, prone to graphitisation at high temperatures (insufficient interlayer spacing), low initial efficiency, requiring pre-oxidation and cross-linking modification.

Application scenarios: Low-end energy storage systems (ESS) and low-speed vehicles, with prices potentially dropping to 20,000-30,000 yuan/mt.

IV. Short-term and Long-term Substitution Strategies

In the short term, biomass-based materials will dominate, with priority given to bamboo-based and straw-based materials (due to low cost and sufficient supply), complemented by some resin-based materials (to enhance the performance of high-end batteries). In the long term, large-scale pitch-based production (after the modification technology matures) + sugar-based/starch-based materials (with advantages in consistency) will be pursued, aiming to reduce the target cost to a level comparable to that of graphite anodes (30,000-50,000 yuan/mt). This will achieve diversified "cost-effective alternatives."

The "cost-effective alternatives" for coconut shell carbon are not a single solution, but rather a diversified matrix of "biomass-based materials as the mainstay, supplemented by resin/pitch-based materials":

Biomass materials such as straw and bamboo-based materials have become the current mainstream choices due to their cost advantages (<1,000 yuan/mt) and supply advantages (100-million-mt scale).

Resin-based materials address the demand for high-end performance, while pitch-based materials target the ultra-low-cost market. Technological iterations will further broaden the boundaries of raw materials, driving the transition of sodium-ion battery hard carbon from "import-dependent" to "self-sufficient and controllable."