Carbon-Coated Tin C@Sn Composite Anode – High-Capacity Sodium-Ion Battery Negative Electrode

Overview of Carbon-Coated Tin Composite Anode

Carbon-coated tin (C@Sn) is a high-capacity composite anode material featuring a typical core-shell structure, where metallic tin serves as the inner core and amorphous hard carbon forms the outer shell. The particles present as near-spherical nano-powders.

The carbon layer enhances electrical conductivity while effectively buffering the volume expansion of tin-based materials during sodium intercalation/deintercalation, achieving an expansion suppression rate of over 50%. This design overcomes the short cycle life and pulverization issues of pure tin anodes, delivering both high specific capacity and long-term cycling stability.

Positioned as a high-capacity anode material for sodium-ion batteries, C@Sn serves as a direct alternative to conventional hard carbon anodes, making it ideal for high-energy-density battery systems.

Features of Carbon-Coated Tin Composite Anode

• Exceptional Capacity Advantage
  With a theoretical specific capacity of 994 mAh/g and practical capacity of approximately 700 mAh/g, this material far surpasses traditional hard carbon anodes (~300 mAh/g), significantly boosting battery energy density.
• Advanced Core-Shell Structural Design
  The carbon shell effectively accommodates the 150%–250% volume expansion of tin-based materials during charge/discharge cycles, suppressing particle pulverization and detachment, thereby substantially extending cycle life.
• Superior Electrical Conductivity
  The carbon layer forms a continuous conductive network that reduces electrode internal resistance and enhances rate performance—delivering 460 mAh/g at 1C and maintaining 260 mAh/g even at 10C.
• Excellent Compatibility
  The manufacturing process is fully compatible with existing sodium-ion battery production lines, requiring no major equipment modifications. It can be used as a direct drop-in replacement or in blended formulations with other anode materials.
• Outstanding Performance Benchmark
  Compared to pure tin anodes, C@Sn demonstrates significantly improved cycling stability and initial Coulombic efficiency (83% vs. 75%). Versus hard carbon, it offers a compelling capacity advantage (700 vs. 300 mAh/g).

Technical Parameters of Carbon-Coated Tin Composite Anode

Physical Properties

Parameter	Specification Range	Typical Value
Tin Content (wt%)	15 – 50	25
Carbon Content (wt%)	50 – 85	75
Particle Size D50 (nm)	50 – 200	100
Carbon Shell Thickness (nm)	18 – 30	20
Specific Surface Area (BET, m²/g)	50 – 200	120
Tap Density (g/cm³)	0.8 – 1.2	1.0
Metal Impurities (Fe/Cu/Pb, ppm)	< 10	< 8
Sodium Ion Residue (ppm)	300 – 400	≤ 350
Crystal Structure	Tetragonal Sn + Amorphous Carbon	No impurity phases

Electrochemical Performance (Half-Cell, vs Na⁺/Na, 0.01–2.0 V)

Parameter	Specification Range	Typical Value
0.1C Initial Discharge Capacity (mAh/g)	600 – 750	700
0.1C Initial Charge Capacity (mAh/g)	500 – 620	580
Initial Coulombic Efficiency (%)	80 – 85	83
0.2C Capacity after 100 Cycles (mAh/g)	450 – 550	520
0.5C Capacity Retention after 500 Cycles (%)	≥ 80	82
1C Rate Capacity (mAh/g)	400 – 500	460
10C Rate Capacity (mAh/g)	200 – 300	260
Sodium Intercalation Volume Expansion (%)	150 – 250	200

Electrode Formulation Guidelines

Parameter	Specification Range
Electrode Areal Loading (mg/cm²)	1.5 – 3.0
Electrode Compaction Density (g/cm³)	1.0 – 1.4
Recommended Electrode Formulation (Active : Conductive Agent : Binder)	80–90 : 5–10 : 5–10
Recommended Electrolyte	1 M NaPF₆ in EC/DMC with 5% FEC additive

Applications of Carbon-Coated Tin Composite Anode

• Energy Storage Batteries
  Large-scale grid storage, commercial & industrial energy storage, and residential storage systems—particularly suited for high-energy-density applications.
• Low-Speed New Energy Vehicles
  Electric two-wheelers, three-wheelers, and other light electric vehicle power batteries, balancing cost with extended range.
• Consumer Electronics
  Small digital devices, wearable electronics, and backup power supplies requiring high safety and long runtime.
• Specialty Power Sources
  Industrial backup batteries, outdoor portable power stations, and rail transit auxiliary power supplies with wide temperature tolerance and high-rate capability.
• Research & Development
  High-energy-density sodium-ion battery R&D, fundamental and applied research on novel composite anode materials (e.g., C@Sn combined with other carbon materials).

Company Profile

Luoyang Tongrun Nano Technology Co., Ltd. (TRUNNANO) is a global supplier and manufacturer of high-performance battery materials. We specialize in lithium-ion, sodium-ion, and other advanced battery materials, serving 3C electronics, power batteries, and energy storage systems.

Our products include nano cobalt oxide, nano manganese oxide, silicon-carbon anode materials, hard carbon, NFPP, alumina, boron nitride, and more. All are produced under strict quality control, supported by our in-house lab and professional technical team.

If you are looking for reliable battery materials, feel free to contact us or send an inquiry.

Payment Methods

L/C, T/T, Western Union, Paypal, Credit Card, etc.

Shipment

By sea, by air, or by express upon payment receipt.

Package of Carbon-Coated Tin Composite Anode

Standard Packaging

• Sealed vacuum packaging with moisture-barrier protection.
• Packaging options include aluminum-laminated film bags or PE bags, placed inside sturdy cartons.

Packaging Dimensions & Weight

• Net weight per carton: 20 kg (4 × 5 kg inner bags)
• Inner bag: 5 kg/bag in aluminum-laminated film or PE bag
• Carton dimensions: 600 × 500 × 400 mm
• PE bag dimensions: 600 × 400 mm

Storage & Handling Requirements

• Store in a dry, cool, well-ventilated environment away from moisture and contaminants.
• Palletized storage recommended; maximum stack height: 3 layers.
• Handle with care during transport; do not place heavy or sharp objects on cartons.
• Shelf life: 12 months from date of manufacture under sealed, recommended storage conditions.
• After opening, unused material must be immediately vacuum-sealed and used within 48 hours to maintain optimal performance.

5 FAQs of Carbon-Coated Tin Composite Anode

Q1: How does C@Sn compare to conventional hard carbon anodes?
C@Sn offers more than double the practical capacity (~700 mAh/g vs. ~300 mAh/g for hard carbon), delivering significantly higher energy density while maintaining good cycling stability through its protective carbon shell design.

Q2: What is the volume expansion rate of this material?
The sodium intercalation volume expansion is 150%–250%, but the carbon shell effectively buffers this expansion, suppressing pulverization and maintaining electrode integrity over extended cycling.

Q3: Is this material compatible with existing production lines?
Yes, the C@Sn composite is fully compatible with standard sodium-ion battery manufacturing processes and can be used as a direct replacement or in blended formulations with hard carbon or other anode materials.

Q4: What electrolyte is recommended for optimal performance?
We recommend 1 M NaPF₆ in EC/DMC with 5% FEC additive for best results. This electrolyte system supports stable solid-electrolyte interphase formation and long cycle life.

Q5: How should partially used material be handled?
After opening the vacuum packaging, any remaining material must be immediately resealed under vacuum and stored in a dry environment. It should be used within 48 hours to prevent moisture absorption and performance degradation.