Sodium-Ion Anode Retains 90% Capacity Over 3,000 Cycles
The research-stage graphene-coated titanium dioxide design targets sodium-ion batteries' durability gap with lithium-ion, pending full-cell tests.
Updated on Nov. 3, 2026 in Materials Science
Chemists at Fudan University in China have developed a sodium-ion battery anode built from ultrathin titanium dioxide nanosheets wrapped in a graphene-based protective shell. The electrode retained more than 90% of its capacity after 3,000 cycles at a relatively high active-material loading. This is a research-stage result; the work has not been reported as a commercial product.
Why it matters
Researchers are seeking more sustainable alternatives to lithium-ion technology, and sodium is approximately 1,000 times more abundant than lithium. Sodium-ion batteries still trail lithium-ion counterparts in power and energy density, so durability gains like this one target one of the field's main weaknesses.
The reported figures are over 90% capacity retention across 3,000 charge-discharge cycles, measured at a relatively high active-material loading. The extraction does not provide a comparison against a prior sodium-ion anode or a lithium-ion benchmark, and the test was conducted on the anode material rather than a complete battery cell.
The players
Fudan University
A leading Chinese university whose researchers developed the graphene-armoured titanium dioxide sodium-ion anode.
University of Birmingham
A UK research university whose researcher provided outside commentary on the work.
The details
The anode is made of ultrathin nanosheets of titanium dioxide, a stable metal oxide, wrapped in a graphene-based shell. Graphene is a single-layer sheet of carbon atoms that conducts electricity well. The nanosheets give sodium ions a short, open path to move in and out of the electrode, which supports fast charging and discharging. The graphene coating improves electrical conductivity and helps protect the anode's structure over repeated cycling. The electrode was produced with established processing steps: forming the particles, coating them with carbon, and heat-treating the material.
The Tech Race
Sodium-ion batteries are positioned as a lower-cost, more abundant alternative to lithium-ion, but they still trail on power and energy density. This anode result addresses durability and cycling stability, one of the parameters researchers are working to improve as the field pursues competitive sodium-ion cells.
This is a laboratory result, and no commercial availability, pricing or launch timeline has been announced. Any eventual benefit for users would depend on the material being validated in full cells and produced at scale, which the researchers say has not yet been demonstrated.
The takeaway
Watch for full-cell testing and scale-up results that show whether the 3,000-cycle durability holds outside the lab. The next meaningful signal would be a demonstration that consistent quality and yield can be achieved with larger production equipment.
Further reading
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