Xu Zhang

This review connects active lithium loss with the rational design of cathode LRCs, highlighting one-shot, sustained-release compensationand AI-assisted synergistic Li ⁺ compensation.

A co-solvent 1,2,3-trifluorobenzene is employed to accelerate the kinetics of AlCl ₃ /acetamide electrolyte for Al–S batteries, not only reducing the viscosity and increasing the conductivity, but also regulating the interphase structures on Al anode.

A graphite coating layer can effectively protect the Al anode against dendrite growth, exhibiting much enhanced cycle stability and reduced overpotential.

A pyridyl-functionalized mesoporous graphene is developed to accommodate sulfur for Al-S batteries, which contributed to the lowest voltage hysteresis (∼0.43 V) and fast reaction kinetics of Al–S battery without catalyst.

An improved template method has been developed to synthesize subnanometer-thick 2D GaN films through the balance of nitridation and ion etching during N₂ plasma enhanced CVD.

A N-doped hierarchical porous carbon material can effectively regulate the electrochemical reactions of S for high-capacity and high-reversibility Al–S batteries. The dominant discharge product was explicitly demonstrated to be tetra-coordinated Al ₂ S ₃ .

The high-capacity phosphorus- (P-) based anode materials for sodium-ion batteries (NIBs) often face poor performance retentions owing to the low conductivity and large volume expansion. It is thus essential to buffer these problems by appropriately alloying with other elements such as tin (Sn) and constructing well-designed microstructures. Herein, a series of P-/Sn-based composites have been synthesized by the facile and low-cost one-step ball milling. Pair distribution function (PDF) has been employed as a hardcore quantitative technique to elucidate their structures combined with other techniques, suggesting the formation and ratios of Sn ₄ P ₃ and Sn crystalline domains embedded inside an amorphous P/carbon matrix. The composite with the largest amount of Sn ₄ P ₃ in the P/C matrix can deliver the most balanced electrochemical performance, with a capacity of 422.3 mA-h g ⁻¹ for 300 cycles at a current density of 1000 mA g ⁻¹ . The reaction mechanism has been elucidated by ²³ Na and ³¹ P solid-state nuclear magnetic resonance (NMR) investigations. The study sheds light on the rational design and concrete identification of P-/Sn-based amorphous-dominant composite materials for NIBs.

Titanium-based layered oxides (TLOs) are one of the most promising electrode material families for sodium-ion batteries (NIBs) due to their smooth charge/discharge profiles and excellent cycle performance. However, the reaction mechanism of these materials, especially the reason for the disappearance of multiple voltage plateaus, is still not clear. Herein, two representative TLOs (Na_2/3Ni_1/3Ti_2/3O₂ and Na_2/3Co_1/3Ti_2/3O₂) with the same P2 crystal structure have been studied to scrutinize those unexplained issues. In situ synchrotron high-energy X-ray diffraction revealed a solid solution reaction mechanism for both, suggesting the absence of rigid phase transitions upon electrochemical cycling. An interesting “spring effect” of the TiO₆ octahedron, i.e., the reversible vibration of the central Ti atom inside the local octahedron upon electrochemical redox, was demonstrated by advanced X-ray absorption spectroscopy and theoretical calculations. Such an effect could suppress the rigid phase transitions, and result in smooth charge/discharge profiles and enhanced cycle stability. This work not only accounts for the disappearance of multiple voltage plateaus of TLOs for NIBs, but also provides an effective local-structure viewpoint to increase the cycle stability of electrode materials for other advanced battery systems.

The development of next-generation energy storage materials for secondary batteries relies more and more on the delicate design and tailoring of their local structures and properties. Crystalline domain battery materials (CDBMs) are defined as a family of materials that are hierarchically engineered primarily by bonding selective atoms in certain space groups with short-range order to form nanoscale crystal domains as fundamental constructive and functional units, secondarily by integrating these interactive crystal domains under certain configurations into grains to implement electrochemical synergy, and finally by optimizing grains through nanoengineering toward advanced electrode materials. In CDBMs, adjacent crystal domains can undergo structural co-transformations with noticeable interrelationships, and the overall electrochemical performance is determined not only by the intrinsic structure of each crystal domain (element, bonding, valence, stacking, orientation, etc.) but also by the configuration of crystal domains (size, ratio, interface, distribution, interaction, etc.). Pioneering studies have shown significant enhancement of electrochemical performance by controlling crystal domains, suggesting the prospect of developing novel electrode materials through crystal-domain engineering. However, fundamental understanding and delicate fabrication of this material family, in terms of structural identification, electrochemical structure evolution, reaction mechanism, design and adjustment, and structure–performance relationship, among others, still face great challenges to meet the compelling requirements of high-performance electrode materials for secondary batteries. This Account systematically introduces the structure and electrochemistry of CDBMs. The efficient structural identification of crystal domains, which is still challenging due to their structural complexity, is demonstrated using prototype materials by advanced characterization techniques such as high-energy X-ray diffraction combined with Rietveld refinement and spherical aberration-corrected transmission electron microscopy. Investigations on the structural evolution of CDBMs in electrochemical reactions by ex-situ and in-situ techniques provide insights into reaction scenarios such as how ions migrate in and across crystal domains and how these crystal domains transform synergistically. A crystal-domain reaction mechanism is thus proposed to explain the electrochemistry of these materials. Design principles and adjustment strategies for designated crystal-domain structures including their components, ratios, distributions, and interfaces are deduced from the structural identification, evolution and reaction mechanism. The relationship between crystal-domain structures and electrochemical performance can further be elucidated, inspiring us to explore efficient strategies for optimizing the electrochemical performance, as validated by examples of high-performance batteries using materials with controlled crystal-domain structures. Based on these systematic studies, the trends in the rapid enrichment, deep investigation, and practical application of CDBMs are envisioned to promote continuous studies on this nascent energy storage material family.