A quantitative analytical framework combining ion chromatography, electrochemical quartz crystal microbalance, and X-ray photoelectron spectroscopy reveals that a tetraglyme-based electrolyte promotes an anion-enriched solvation shell, yielding a dense, inorganic-rich solid electrolyte interphase (SEI) on hard carbon anodes. This optimized structure suppresses total SEI dissolution and achieves exceptional cycling stability in sodium-ion pouch cells. ABSTRACT Anode interphase dissolution is a major cause of instability in sodium-ion batteries (SIBs) because Na-based solid electrolyte interphase (SEI) compounds are more soluble than their Li analogues. Here, glyme electrolytes with varied chain lengths are used to regulate Na+ solvation structure and clarify its effect on SEI dissolution. A component-resolved framework combining ion chromatography, mass spectrometry, electrochemical quartz crystal microbalance, and X-ray photoelectron spectroscopy is developed to quantify the dissolution and retention of organic and inorganic SEI species. This approach determines absolute SEI retention rather than relying on aggregate interphase loss. Compared with the glyme, tetraglyme reduces total SEI dissolution from 75% to 53% and increases the retention of inorganic F-containing species from 18% to 30%. This improvement arises from an anion-enriched Na+ solvation shell, which promotes the formation of a thinner, denser, and more inorganic-rich SEI. Consequently, 1.25 Ah NaNi1/3Fe1/3Mn1/3O2||hard carbon pouch cells using the tetraglyme-based electrolyte retain 91.2% capacity after 500 cycles and exhibit stable voltage retention during 21-day aging at 60°C. These results establish a quantitative methodology for distinguishing the dissolution behavior of organic and inorganic SEI components, reveal the role of ether chain length in interphase stability, and provide practical guidance for designing durable SIBs.

All-solid-state sodium batteries (ASSBs) offer high energy density and safety, but conventional solid electrolyte interphase (SEI) layers suffer from low efficiency and severe side reactions. This work proposes a novel strategy based on a borate-enriched SEI that effectively suppresses side reactions and enables dendrite-free Na plating/stripping, providing valuable mechanistic insights and a feasible pathway toward high-performance ASSBs.

Understanding how battery components work at the molecular or atomic levels can help scientists create faster-charging, more powerful, longer-lived storage devices.

The Solid Electrolyte Interphase (SEI) Forming Additives Market was valued at USD 1.2 billion in 2025 and is poised to grow from USD 1.

Cost-effective Li2ZrCl6 halides with regulated configurational complexity combine rapid lithium-ion conduction with ultralow electronic conductivity and superior oxidative stability. A robust zirconium oxychloride cathode-electrolyte interphase is formed during cycling, enabling 4.4 V all-solid-state LiNi0.85Co0.1Mn0.05O2 batteries to operate for up to 3,700 cycles.

The Solid Electrolyte Interphase (SEI) Forming Additives Market was valued at USD 1.2 billion in 2025 and is poised to grow from USD 1.

Polycrystalline Li-rich layered cathodes suffer from oxygen loss and grain-boundary degradation during cycling. Here, tannic-acid-assisted infiltration drives Ba to the outer surface and buried grain boundaries, where heat treatment converts it into an epitaxially coupled BaMO3− δ interphase. This ultrathin passivation layer suppresses oxygen release and interfacial side reactions, stabilizing oxygen redox and improving long-term cycling. ABSTRACT High-voltage cathodes with hybrid anion and cation redox activities, such as Li-rich and Mn-rich oxides, offer a pathway to higher energy density in lithium-ion batteries (LIBs). However, those cathodes suffer from oxygen loss from both the surface and grain boundaries, especially in traditional polycrystalline cathodes with secondary-particle morphology. Interfacial passivation is needed, yet uniform, high-quality coating at both primary- and secondary-particle levels remains challenging. Here, using a tannic acid-assisted process, we demonstrate an in situ formed BaMO3− δ (M = Ni, Co, and Mn) perovskite phase at surfaces and grain boundaries, offering effective passivation to suppress structural and electrochemical degradation. Differential electrochemical mass spectrometry (DEMS), soft X-ray spectroscopy (SXAS) and resonant inelastic X-ray spectroscopy (RIXS) reveal that the passivated grain boundaries effectively mitigate oxygen release, promote the retention of oxidized oxygen within the grains, and improve oxygen-redox reversibility. The stabilization is facilitated by strong M─O bonding at primary-particle surfaces, improving energy-density stability and mitigating voltage decay. The improved electrochemical performance results from the reliable coating method, which constructs sequential interfacial bonding along grain boundaries. Using earth-abundant elements only, this process may offer high-quality passivation for a variety of oxide cathodes used in LIBs and beyond.

One attractive feature of van der Waals materials is their potential to be combined into sandwich structures that generate unique properties. Here, Wichmann et al proved a clear example of this, demonstrating the emergence of electric field tuneable Zeeman interactions with ultra large g-factors at the interface of Fe3GeTe2 and graphene.

The kinetochore is an essential structure for the faithful chromosome segregation during mitosis. The 16-protein complex known as the constitutive centromere-associated network (CCAN) localizes the ce...

Centrosome cohesion mechanisms link the two interphase centrosomes into a single microtubule-organizing center that is closely associated with the Golgi apparatus. The contribution of cohesion mechani...