Synergy of I-Cl co-occupation on halogen-rich argyrodites and resultant dual-layer interface for advanced all-solid-state Li metal batteries

The(electro)chemical stability and Li dendrite suppression capability of sulfide solid electrolytes(SEs)need further improvement for developing all-solid-state Li batteries(ASSLBs).Here,we report advanced halogen-rich argyrodites via I and Cl co-occupation on the crystal lattice.Notably,a proper I content forms a single phase,whereas an excessive I causes precipitation of two argyrodite phases like a superlattice structure.The resultant synergistic effect of the optimized composition allows to gain high ionic conductivities at room temperature and-20℃,and enhances the(electro)chemical stability against Li and Li dendrite suppression capability.The Li|argyrodite interface is very sensitive to the ratio of I and Cl.A LiCl-and LiI-rich double-layer interface is observed from the cell using the SE with optimized composition,whereas too high I content forms only a single interface layer with a mixture of Lil and LiCl.This double-layer interface is found to effectively mitigate the Li/SE reaction.The proper designed argyrodite enables ASSLBs to achieve good electrochemical properties at a broad temperature range regardless of the electrode materials.This co-occupation strategy provides a novel exploration for advanced halogen-rich argyrodite system.

LiNbO3-coated LiNi0.8Co0.1Mn0.1O2 cathode with high discharge capacity and rate performance for all-solid-state lithium battery

In order to obtain high power density,energy density and safe energy storage lithium ion batteries(LIB)to meet growing demand for electronic products,oxide cathodes have been widely explored in all-solidstate lithium batteries(ASSLB)using sulfide solid electrolyte.However,the electrochemical performances are still not satisfactory,due to the high interfacial resistance caused by severe interfacial instability between sulfide solid electrolyte and oxide cathode,especially Ni-rich oxide cathodes,in charge-discharge process.Ni-rich LiNi0.8Co0.1Mn0.1O2(NCM811)material at present is one of the most key cathode candidates to achieve the high energy density up to 300 Wh kg^-1 in liquid LIB,but rarely investigated in ASSLB using sulfide electrolyte.To design the stable interface between NCM811 and sulfide electrolyte should be extremely necessary.In this work,in view of our previous work,LiNbO3 coating with about 1 wt% content is adopted to improve the interfacial stability and the electrochemical performances of NCM811 cathode in ASSLB using Li10GeP2S12 solid electrolyte.Consequently,LiNbO3-coated NCM811 cathode displays the higher discharge capacity and rate performance than the reported oxide electrodes in ASSLB using sulfide solid electrolyte to our knowledge.

Tailoring lithium concentration in alloy anodes for long cycling and high areal capacity in sulfide-based all solid-state batteries

Lithium–indium(Li-In)alloys are important anode materials for sulfide-based all-solid-state batteries(ASSBs),but how different Li concentrations in the alloy anodes impact the electrochemical performance of ASSBs remains unexplored.This paper systematically investigates the impact that different Li concentrations in Li-In anodes have on the performance of ASSBs.We show that In with 1 wt%Li(LiIn-1)exhibits the best performance for ASSBs among all the tested Li-In anodes.In essence,LiIn-1 not only provides sufficient Li to compensate for first-cycle capacity loss in the anode but also facilitates the formation of a LiIn alloy phase that has the best charge transfer kinetics among all the Li_(x) In alloy phases.The ASSB with a LiIn-1 anode and a LiNi_(0.8)Mn_(0.1)Co_(0.1)O_(2) cathode reached 3400 cycles at an initial capacity of 125 mAh/g.Remarkably,ASSBs with a high cathode active material(CAM)loading of 36 mg/cm 2 delivered a high areal capacity of 4.05 mAh/cm^(2) at high current density(4.8 mA/cm^(2)),with a capacity retention of 92% after 740 cycles.At an ultra-high CAM loading of 55.3 mg/cm^(2),the ASSB achieved a stable areal capacity of 8.4 mAh/cm^(2) at current density of 1.7 mA/cm 2.These results bring us one step closer to the practical application of ASSBs.

Boosting the energy density of sulfide-based all-solid-state batteries at low temperatures by charging to high voltages up to 6 V

Sulfide electrolyte-based all-solid-state batteries(ASSBs)are potential next generation energy storage technology due to the high ionic conductivity of sulfide electrolytes and potentially improved energy density and safety.However,the performance of ASSBs at/below subzero temperatures has not been explored systematically.Herein,low temperature(LT)performance of LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2)(NCM811)|Li_(9.54)Si_(1.74)P_(1.44)S11.7Cl_(0.3)(LiSPSCl)|Li_(4)Ti_(5)O_(12)(LTO)ASSBs was investigated.By charging the ASSB to 6 V at−40℃,a capacity of 100.7 mAh∙g^(−1)at 20 mA∙g^(−1)was achieved,which is much higher than that charged to 4.3 V(4.6 mAh∙g^(−1))at−40℃.Moreover,atomic resolution microscopy revealed that the NCM811 remained almost intact even after being charged to 6 V.In contrast,NCM811 was entirely destructed when charged to 6 V at room temperature.The sharp difference arises from the large internal charge transfer resistance at LT which requires high voltage to overcome.Nevertheless,such high voltage is not harmful to the active material but beneficial to extracting most energy out of the ASSBs at LT.We also demonstrated that thinner electrolyte is favorable for LT operation of ASSBs due to the reduced ion transfer distance.This work provides new strategies to boost the capacity and energy density of sulfide-based ASSBs at LT for dedicated LT applications.