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A nanowire-on-microrod structured polyaniline (PANI)@FeS2 hybrid was developed via a facile metal–organic framework (MOF)-derived chemical method. The in situ grown PANI nanowires on the surface of pyramidal FeS2 microrods displayed better mechanical flexibility and improved Al-storage performance. The PANI nanowires not only enhanced electron transfer during the electrochemical reaction, but also accommodated the volume expansion of FeS2 during discharge. The PANI@FeS2 hybrid as the cathode in AIBs delivered a reliable battery capacity of 152.8 mA h g−1 along with a Coulombic efficiency of >96.5% after 500 cycles at a current density of 1.5 A g−1. In addition, a high capacity retention of 160.2 mA h g−1 after 150 cycles at 0.5 A g−1 at −10 °C was achieved. These findings provide a feasible strategy by constructing a nanowire-on-microrod hybrid that can be applied in high-performance secondary batteries. [ABSTRACT FROM AUTHOR]

Emerging power batteries with both high volumetric energy density and fast charge/discharge kinetics are required for electric vehicles. The rapid ion/electron transport of mesostructured electrodes enables a high electrochemical activity in secondary batteries. However, the typical low fraction of active materials leads to a low volumetric energy density. Herein, we report a novel biomimetic “bee pupa infilled honeycomb”-structured 3D mesoporous cathode. We found previously the maximum active material filing fraction of an opal template before pinch-off was about 25%, whereas it could be increased to ∼90% with the bee pupa-infilled honeycomb-like architecture. Importantly, even with a high infilling fraction, fast Li+/e− transport kinetics and robust mechanical property were achievable. As the demonstration, a bee pupa infilled honeycomb-shaped Li2MnSiO4/C cathode was constructed, which delivered a high volumetric energy density of 2443 W h L−1. The presented biomimetic bee pupa infilled honeycomb configuration is applicable for a broad set of both cathodes and anodes in high energy density batteries. [ABSTRACT FROM AUTHOR]

A three-dimensional all-in-one Sn–Co alloy anode is reported for the first time, which delivers a high capacity along with a stable coulombic efficiency as well as good temperature tolerance. The binder-free electrode eliminates the complexity of conventional slurry preparation while maintaining an integrated scaffold, which provides space to accommodate volume expansion, as confirmed by an in situ transmission electron microscopy study. [ABSTRACT FROM AUTHOR]

A methodology to screen additives in lead-acid batteries is critical. We developed a three-electrode system that can rapidly check the dynamic charge acceptance (DCA) and hydrogen evolution of electrodes. The electrode with 2% MXene and 0.2% carbon black shows a better DCA, which indicates its great potential in the start–stop technology. [ABSTRACT FROM AUTHOR]

A novel battery hybrid composite anode consisting of tin nanoparticles encapsulated by double nets of carbon matrixes is presented. The improved electron transfer and volume change accommodation are confirmed via density functional theory modeling and in situ transmission electron microscopy observations, respectively. [ABSTRACT FROM AUTHOR]

Although lithium–sulfur batteries exhibit a high initial capacity, production costs and lack of cyclability are major limitations. Here we report a liquid-based, low-cost and reliable synthesis method of a lithium–sulfur composite cathode with improved cyclability. An open network of Conductive Carbon Black nanoparticles (Cnet) is infused with a sulfur network (Snet) to form sponge-like networks (Cnet + Snet). Initially, Snet is open to the outside, allowing liquid electrolyte to infiltrate and impart Snet Li+ conductivity. During lithiation, Cnet could accommodate the volume expansion of Snet largely without losing electrical contact. During delithiation, the carbon nanoparticles would preferably flocculate on the outer surface due to polysulfide dissolution and depletion of sulfur, to form a passivation layer that still allows Li+ exchange, but prevents more polysulfides from escaping, thus slowing the leaching of polysulfides into the bulk electrolyte liquid. The plausibility of a carbonaceous passivation layer was checked using an extra carbon deposition layer to achieve an improved performance of ∼400 mA h g−1 after 250 cycles under a high rate 2.0 C. A 763 mA h g−1 discharge specific capacity of this sulfur nanosponge cathode (abbreviated as “SULFUN”) was obtained after 100 cycles under a rate of 0.2 C. Discharge capacities of 520 mA h g−1 and 290 mA h g−1 were attained after 300 and 500 cycles, respectively, making this cathode material attractive for rechargeable battery applications. [ABSTRACT FROM AUTHOR]

A nanowire-on-microrod structured polyaniline (PANI)@FeS 2 hybrid was developed via a facile metal-organic framework (MOF)-derived chemical method. The in situ grown PANI nanowires on the surface of pyramidal FeS 2 microrods displayed better mechanical flexibility and improved Al-storage performance. The PANI nanowires not only enhanced electron transfer during the electrochemical reaction, but also accommodated the volume expansion of FeS 2 during discharge. The PANI@FeS 2 hybrid as the cathode in AIBs delivered a reliable battery capacity of 152.8 mA h g -1 along with a Coulombic efficiency of >96.5% after 500 cycles at a current density of 1.5 A g -1 . In addition, a high capacity retention of 160.2 mA h g -1 after 150 cycles at 0.5 A g -1 at -10 °C was achieved. These findings provide a feasible strategy by constructing a nanowire-on-microrod hybrid that can be applied in high-performance secondary batteries.

Emerging power batteries with both high volumetric energy density and fast charge/discharge kinetics are required for electric vehicles. The rapid ion/electron transport of mesostructured electrodes enables a high electrochemical activity in secondary batteries. However, the typical low fraction of active materials leads to a low volumetric energy density. Herein, we report a novel biomimetic "bee pupa infilled honeycomb"-structured 3D mesoporous cathode. We found previously the maximum active material filing fraction of an opal template before pinch-off was about 25%, whereas it could be increased to ∼90% with the bee pupa-infilled honeycomb-like architecture. Importantly, even with a high infilling fraction, fast Li+/e- transport kinetics and robust mechanical property were achievable. As the demonstration, a bee pupa infilled honeycomb-shaped Li2MnSiO4/C cathode was constructed, which delivered a high volumetric energy density of 2443 W h L-1. The presented biomimetic bee pupa infilled honeycomb configuration is applicable for a broad set of both cathodes and anodes in high energy density batteries.

A methodology to screen additives in lead-acid batteries is critical. We developed a three-electrode system that can rapidly check the dynamic charge acceptance (DCA) and hydrogen evolution of electrodes. The electrode with 2% MXene and 0.2% carbon black shows a better DCA, which indicates its great potential in the start-stop technology.