Main points
- Scientists have developed the RPIC method, which allows for the recovery of “dead” sodium in batteries, extending their service life.
- The method is effective for sodium, lithium, and potassium batteries, but reduces energy efficiency by 16%.
A second life for batteries: scientists have found a way to bring “dead” sodium back to work / Unsplash
The problem of isolated metal buildup, which gradually degrades batteries, has long been considered insurmountable for sodium systems. However, researchers have developed an innovative method that allows the lost capacity to be restored directly during charging.
How do physical effects help reanimate chemical energy sources?
In today's world, the search for alternatives to lithium-ion batteries is becoming critically important due to the limited resources of lithium and its high cost. Sodium batteries (AFSBs) look like a promising replacement, but they have a significant drawback – rapid degradation due to the formation of so-called “dead” sodium. These are metal particles that lose electrical contact with the electrode due to uneven deposition or dissolution of the metal during operation. The accumulation of such “ballast” depletes the supply of active metal and increases the internal resistance of the battery, leading to rapid failure. In a new study, which appeared on May 5 in the journal Nature Communications, scientists offer a way out of this problem.
A group of scientists led by Hua Wang from Beihang University has proposed a revolutionary reverse-pulse-interspersed charging (RPIC) strategy. The essence of the method is that during the normal charging process, short pulses of reverse current are added to the protocol. This allows you to activate a physical phenomenon known as positive dielectrophoresis.
According to the study, in a non-uniform electric field, dead sodium particles, which have a higher complex dielectric constant than the surrounding electrolyte, experience a force that pushes them towards areas of higher field density – that is, back towards the negative electrode. As soon as the “dead” metal touches the active layer on the anode, it is re-connected to the electrical circuit and becomes functional.
How effective is the method?
Experimental data confirm the effectiveness of this approach:
- Using the RPIC strategy has doubled the service life of sodium batteries. For example, laboratory cells of the Al||NFPP type retained 80% of their capacity after 418 cycles, while with the standard charging method this figure was achieved in only 215 cycles at the same charging rate.
- Even more impressive results were demonstrated by full-size batteries with a capacity of ampere-hours: they retained 80% of their capacity after 830 cycles and 74.6% after 1000 cycles at a high charging rate.
In addition to direct metal reactivation, RPIC technology solves several other critical problems:
- Reduction of concentration polarization. The reverse pulse evens out the distribution of sodium ions in the electrolyte, preventing the formation of deficiency zones.
- Dendrite suppression. The strategy promotes the formation of a smooth and uniform metal surface, which minimizes the risk of short circuits due to sharp metal growths.
- Improved electrode kinetics. Due to less dead metal accumulation, the internal resistance of the battery remains low for a long time.
Reactivation of inactive alkali metal is an effective strategy to extend the service life of alkali metal batteries. Until now, relevant research has focused mainly on lithium batteries, but the reactivation of inactive sodium remains a mystery,
– commented the authors of the study, led by Weihao Wang.
The method can also be applied to other types of batteries
The scientists also tested the versatility of their development. It turned out that the RPIC method is effective not only for sodium, but also for lithium and potassium anode-free batteries. This opens the way to creating ultra-powerful energy storage devices with high specific energy.
In particular, the study demonstrated the operation of a sodium battery with a capacity of 180 watt-hours per kilogram, which has a long service life and is suitable for practical applications in electric vehicles or renewable energy storage systems.
There are disadvantages
Despite the fact that the introduction of reverse pulses leads to a slight decrease in energy efficiency (by approximately 16% due to the cost of the pulse itself), the developers emphasize that this is fully compensated by a radical extension of the device's life.
Thus, the RPIC strategy becomes a practical tool for the transition to stable and high-performance alkaline metal batteries of the future.
You will be interested to know: what new developments in the field of batteries are currently being prepared for implementation?
Solid-state batteries
This is perhaps the most talked about trend right now, writes Electrek. The Chinese company Greater Bay Technology has already launched the first prototype samples of all-solid-state battery cells from the assembly line, and they have successfully passed needle puncture, extrusion and thermal shock tests – without ignition or explosion. The declared energy density is 260-500 watt-hours per kilogram, which significantly exceeds the performance of traditional liquid lithium-ion batteries, and charging occurs in fast mode. The company is targeting gigawatt-scale mass production by the end of 2026, and the debut of the first samples of the product is planned in premium models of GAC Hyptec cars.
Overall, the race for solid-state batteries has now turned into a global marathon, according to To7Motors. Toyota aims to achieve a density of 450-500 watt-hours per kilogram in small-scale production between 2027 and 2028, Samsung SDI promises 80% charging in 9 minutes by 2027, and Dongfeng plans mass production at 350 watt-hours per kilogram by the end of 2026.
China also announced the launch of its own standard for solid-state batteries in July 2026.
New breakthroughs in traditional lithium-ion batteries
Even “old” technology is not standing still. Oxford researchers in February 2026 found a way to make lithium-ion batteries charge faster and last longer. All thanks to the labeling of polymer binders, which allows you to more accurately visualize and understand the degradation of battery cells.
In addition, scientists have made a breakthrough in bromine flow batteries by finding a way to chemically contain corrosive bromine, which was previously one of the main barriers to long-term and affordable energy storage, notes ScienceDaily.
Ultra-fast charging
Separately, it is worth noting the progress in the charging speed itself. Ultra-fast charging technology is rapidly redefining the capabilities of electric cars and smartphones, reducing the time from hours to minutes, reports CALSTART. At CES 2026, the Finnish company Donut Lab presented a solid-state battery that can charge in 5 minutes, and has already announced its use in real Verge motorcycles in the first quarter of 2026.