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Ni−rich cathodes are hopeful materials for advanced lithium−ion batteries (LIBs) due to high capacity. Nonetheless, the chemical crosstalk triggered by reactive oxygen (O*) represents a critical factor in thermal runaway (TR). Currently, there are few effective means to prevent this parasitic reaction. Here, inspired by the O* scavenging effect of β−carotene in living organisms, it is innovatively identified that β−carotene can impede TR by restraining the escape of O* during the thermal decomposition of nickel−rich cathodes. Using LiNi0.6Co0.2Mn0.2O2 as model and extending to higher nickel content cathodes (LiNi0.8Co0.1Mn0.1O2, LiNi0.9Co0.05Mn0.05O2), it is demonstrated that β−carotene can undergo an in situ oxygen copolymerization reaction to trapping O*, thereby attenuating chemical crosstalk. Additionally, the generated oxygen copolymer can also adjust band center of the O 2p orbitals of delithiated cathode, alleviating the charge compensation behavior of oxygen anions, and thus delaying the phase transition of charged LiNi0.8Co0.1Mn0.1O2. As a result, the TR trigger temperature of NCM811∣Graphite pouch cell is increased from 131.0 to 195.0 °C and maximum temperature is reduced from 657.8 to 412.4 °C. This work introduces a new and simple strategy for designing functional additives to block TR, offering a promising avenue for advancing the safety of LIBs. [ABSTRACT FROM AUTHOR]

Fluorinated solvents emerge as a promising strategy to improve performance of lithium metal batteries (LMBs). However, most of them are prone to produce corrosive HF and deteriorate electrode interface, inducing cathode‐to‐anode detrimental crossover of transition metal‐ions. Here, fluorinated aromatic hydrocarbons in dimethyl carbonate (DMC)‐based diluted highly concentrated electrolyte (DHCE) are employed to juggle formation of HF and LiF, enabling stable cycling of high‐voltage LiNi0.7Co0.1Mn0.2O2 (NCM712) and LiCoO2 (LCO). The nature of aromatics in this carbonate‐based DHCE makes them difficult to undergo β‐hydrogen assisted defluorination, evidencing by the high energy barrier and high bond energy of β‐sites hydrogen. The advanced DHCE restrains HF formation but strengthens LiF formation, which not only suppresses impedance growth, transition‐metal dissolution, and stress crack on the cathode, but achieves highly reversible Li stripping/plating with an outstanding average Coulombic efficiency up to 99.3%. The Li||NCM712 cell and Li||LCO cell both exhibits superior cycling stability at high operation voltage. Even under stringent conditions, the 4.4 V Li||NCM712 full battery retains >95% of the initial capacity over 100 cycles, advancing practical high‐voltage LMBs. This study designs an efficient electrolyte that generates robust electrode/electrolyte interphases and restrains by‐products formation spontaneously, thus shedding new light on electrolyte toward applicable LMBs. [ABSTRACT FROM AUTHOR]

By increasing the content of Ni 3+ , the catalytic activity of nickel-based catalysts for the oxygen evolution reaction (OER), which is still problematic with current synthesis routes, can be increased. Herein, a Ni 3+ -rich of Ni 3 S 4 /FeS on FeNi Foam (Ni 3 S 4 /FeS@FNF) via anodic electrodeposition to direct obtain high valence metal ions for OER catalyst is presented. XPS showed that the introduction of Fe not only further increased the Ni 3+ concentration in Ni 3 S 4 /FeS to 95.02%, but also inhibited the dissolution of NiOOH by up to seven times. Furthermore, the OER kinetics is enhanced by the combination of the inner Ni 3 S 4 /FeS heterostructures and the electrochemically induced surface layers of oxides/hydroxides. Ni 3 S 4 /FeS@FNF shows the most excellent OER activity with a low Tafel slope of 11.2 mV dec -1 and overpotentials of 196 and 445 mV at current densities of 10 and 1400 mA cm -2 , respectively. Furthermore, the Ni 3 S 4 /FeS@FNF catalyst can be operated stably at 1500 mA cm -2 for 200 h without significant performance degradation. In conclusion, this work has significantly increased the high activity Ni 3+ content in nickel-based OER electrocatalysts through an anodic electrodeposition strategy. The preparation process is time-saving and mature, which is expected to be applied in large-scale industrialization., (© 2023 Wiley‐VCH GmbH.)