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All-carbon graphdiyne (GDY)-based materials have attracted extensive attention owing to their extraordinary structures and outstanding performance in electrochemical energy storage. Straightforward insights into the interfacial evolution at GDY electrode/electrolyte interface could crucially enrich the fundamental comprehensions and inspire targeted regulations. Herein

Gel polymer electrolytes (GPEs) are one of the promising candidates for high-energy-density quasi-solid-state lithium metal batteries (QSSLMBs), for their high ionic conductivity and excellent interfacial compatibility. The comprehension of dynamic evolution and structure-reactivity correlation at the GPE/Li interface becomes significant. Here, in situ electrochemical atomic force microscopy (EC-AFM) provides insights into the LiNO3-regulated micromechanism of the Li plating/stripping behavior upon cycles in GPE-based LMBs at nanoscale. The additive LiNO3 induces the formation of amorphous nitride SEI film and facilitates the Li+ ion diffusion. It stabilizes a compatible interface and regulates the Li nucleation/growth at steady kinetics. The deposited Li is in the shape of chunks and tightly compact. The Li dissolution shows favorable reversibility, which guarantees the cycling performance of LMBs. In situ AFM monitoring provides a deep understanding into the dynamic evolution of Li deposition/dissolution and the interphasial properties of tunable SEI film, regulating the rational design of electrolyte and interfacial establishment for GPE-based QSSLMBs.

Catalysts with two single-atom sites promote reversible conversion reactions between S and Li2S. The Co active site enhances the transformation kinetics of polysulfides upon charging, the Fe active site accelerates the transformation of Li2S to S8.

Micrometre-sized electrode materials have distinct advantages for battery applications in terms of energy density, processability, safety and cost. For the silicon monoxide anode that undergoes electrochemical alloying reaction with Li, the Li (de)intercalation by micron-sized active particles usually accompanies with a large volume variation, which pulverizes the particle structure and leads to rapidly faded storage performance. In this work, we proposed to stabilize the electrochemistry vs. Li of the micron-SiOx anode by forming a rigid-flexible bi-layer coating on the particle surface. The coating consists of pyrolysis carbon as the inner layer and polydopamine as the outer layer. While the inner layer guarantees high structural rigidity at particle surface and provides efficient pathway for electron conduction, the outer layer shows high flexibility for maintaining the integrity of micrometre-sized particles against drastic volume variation, and together they facilitate formation of stable solid electrolyte interface on the SiOx particles. A composite anode prepared by mixing the coated micron-SiOx with graphite delivered improved Li storage performance, and promised a high-capacity, long-life LiFePO4/SiOx-graphite pouch cell. Our strategy provides a general and feasible solution for building high-energy rechargeable batteries from micrometre-sized electrode materials with significant volume variation.

Safety concerns related to the abuse operation and thermal runaway are impeding the large-scale employment of high-energy-density rechargeable lithium batteries. Here, we report that by incorporating phosphorus-contained functional groups into a hydrocarbon-based polymer, a smart risk-responding polymer is prepared for effective mitigation of battery thermal runaway. At room temperature, the polymer is (electro)chemically compatible with electrodes, ensuring the stable battery operation. Upon thermal accumulation, the phosphorus-containing radicals spontaneously dissociate from the polymer skeleton and scavenge hydrogen and hydroxyl radicals to terminate the exothermic chain reaction, suppressing thermal generation at an early stage. With the smart risk-responding strategy, we demonstrate extending the time before thermal runaway for a 1.8-Ah Li-ion pouch cell by 100% (~9 hours) compared with common cells, creating a critical time window for safety management. The temperature-triggered automatic safety-responding strategy will improve high-energy-density battery tolerance against thermal abuse risk and pave the way to safer rechargeable batteries.

By applying a LiF-rich in situ solidified Li+-conductive interlayer, the interfacial contact and charge transfer stability between LPS and Li metal are notably improved, which leads to dendrite-free Li plating/stripping at the interface.

Lithium-sulfur batteries are promising candidates of energy storage devices. Both adjusting salt/solvent ratio and applying quasi-solid-state electrolytes are regarded as effective strategies to improve the lithium (Li) anode performance. However, reaction mechanisms and interfacial properties in quasi-solid-state lithium-sulfur (QSSLS) batteries with high salt concentration are not clear. Here we utilize in-situ characterizations and molecular dynamics simulations to unravel aforesaid mysteries, and construct relationships of electrolyte structure, interfacial behaviour and performance. The generation mechanism, formation process, and mechanical/chemical/electrochemical properties of the anion-derived solid electrolyte interphase (SEI) are deeply explored. Li deposition uniformity and dissolution reversibility are further tuned by the sustainable SEI. These straightforward evidences and deepgoing studies would guide the electrolyte design and interfacial engineering of QSSLS batteries.

The interfacial stability is highly responsible for the longevity and safety of sodium ion batteries (SIBs). However, the continuous solid-electrolyte interphase(SEI) growth would deteriorate its stability. Essentially, the SEI growth is associated with the electron leakage behavior, yet few efforts have tried to suppress the SEI growth, from the perspective of mitigating electron leakage. Herein, we built two kinds of SEI layers with distinct growth behaviors, via the additive strategy. The SEI physicochemical features (morphology and componential information) and SEI electronic properties (LUMO level, band gap, electron work function) were investigated elaborately. Experimental and calculational analyses showed that, the SEI layer with suppressed growth delivers both the low electron driving force and the high electron insulation ability. Thus, the electron leakage is mitigated, which restrains the continuous SEI growth, and favors the interface stability with enhanced electrochemical performance.

In Li-ion batteries, functional cosolvents could significantly improve the specific performance of the electrolyte, for example, the flame retardancy. In case the cosolvent shows strong Li

As two stable hydrogen isotopes, protium and deuterium show magnified isotope effects in physicochemical properties due to the significantly varied atomic masses. In this work, aqueous electrolytes based on heavy water (D

With the ever increasing demand for low-cost and economic sustainable energy storage, Na-ion batteries have received much attention for the application on large-scale energy storage for electric grids because of the worldwide distribution and natural abundance of sodium element, low solvation energy of Na

In recent years, micrometer-sized Si-based anode materials have attracted intensive attention in the pursuit of energy-storage systems with high energy and low cost. However, the significant volume variation during repeated electrochemical (de)alloying processes will seriously damage the bulk structure of SiO

Sodium-ion batteries (SIBs) are currently the most promising candidates for large-scale energy storage devices owing to their low cost and abundant resources. Titanium-based layered oxides have attracted widespread attention as promising anode materials due to delivering a safe potential of about 0.7 V (vs Na

Chemical modification of electrode materials by heteroatom dopants is crucial for improving storage performance in rechargeable batteries. Electron configurations of different dopants significantly influence the chemical interactions inbetween and the chemical bonding with the host material, yet the underlying mechanism remains unclear. We revealed competitive doping chemistry of Group IIIA elements (boron and aluminum) taking nickel-rich cathode materials as a model. A notable difference between the atomic radii of B and Al accounts for different spatial configurations of the hybridized orbital in bonding with lattice oxygen. Density functional theory calculations reveal, Al is preferentially bonded to oxygen and vice versa, and shows a much lower diffusion barrier than B

Organic compounds possess great potential as electrode materials for environmentally friendly and sustainable batteries due to their abundance, recyclability, and highly tailorable properties. However, commercialization remains difficult due to several intrinsic problems, including high solubility in electrolytes and low conductivity. Aromatic organic compounds used as anode materials in batteries continue to exhibit severe degradation problems, especially with respect to long-term cycling performance. By using direct molecular design, the stability and conductivity of organic compounds can be modified. Here, we report the design and preparation of π-conjugated polypyrene porous nanoflowers, formed with micro- and mesoporous nanosheets, via a facile one-pot polymerization process. The porous structure at the nanoscale was expected to offer large contact area for electrolyte and short ionic immigration distance, facilitating fast ion diffusion kinetics. When evaluated as an anode for potassium ion batteries, the polypyrene demonstrated excellent long-term cycling stability and improved rate capability. This outstanding electrochemical performance is due to the π-conjugated skeleton showing low solubility in conventional electrolytes, highly stable structure, and meso- and microporous structure, which can not only shorten charge transfer paths, but also enhance ion diffusion kinetics. This approach of utilizing π-conjugated polymer with highly stable structure and porous nanostructures is expected to inspire new research on the development of novel organic electrode materials for rechargeable ion batteries.

Lithium-metal anodes show significant promise for the construction of high-energy rechargeable batteries due to their high theoretical capacity (3860 mAh g-1) and low redox potential (-3.04 V vs. a standard hydrogen electrode). When Li metal is used with conventional liquid and solid electrolytes, the poor lithiophilicity of the electrolyte results in an unfavorable parasitic reaction and uneven distribution of Li+ flux at the electrode/electrolyte interface. These issues result in limited cycle life and dendrite problems associated with the Li-metal anode that can lead to rapid performance fade, failure and even safety risks of the battery. The lithiophilicity at the anode/electrolyte interface is important for the stable and safe operation of rechargeable Li-metal batteries. In this review, several factors that affect the lithiophilicity of electrolytes are discussed, including surface energy, roughness and chemical interactions. The existing problems and the strategies for improving the lithiophilicity of different electrolytes are also discussed. This review helps to shed light on the understanding of interfacial chemistry vs. Li metal of various electrolytes and guide interfacial engineering towards the practical realization of high-energy rechargeable batteries.