A Bifunctional-Modulated Conformal Li/Mn-Rich Layered Cathode for Fast-Charging, High Volumetric Density and Durable Li-Ion Full Cells

Abstract

Lithium- and manganese-rich (LMR) layered cathode materials hold the great promise in designing the next-generation high energy density lithium ion batteries. However, due to the severe surface phase transformation and structure collapse, stabilizing LMR to suppress capacity fade has been a critical challenge. Here, a bifunctional strategy that integrates the advantages of surface modification and structural design is proposed to address the above issues. A model compound Li1.2Mn0.54Ni0.13Co0.13O2 (MNC) with semi-hollow microsphere structure is synthesized, of which the surface is modified by surface-treated layer and graphene/carbon nanotube dual layers. The unique structure design enabled high tap density (2.1 g cm−3) and bidirectional ion diffusion pathways. The dual surface coatings covalent bonded with MNC via C-O-M linkage greatly improves charge transfer efficiency and mitigates electrode degradation. Owing to the synergistic effect, the obtained MNC cathode is highly conformal with durable structure integrity, exhibiting high volumetric energy density (2234 Wh L−1) and predominant capacitive behavior. The assembled full cell, with nanographite as the anode, reveals an energy density of 526.5 Wh kg−1, good rate performance (70.3% retention at 20 C) and long cycle life (1000 cycles). The strategy presented in this work may shed light on designing other high-performance energy devices.

Microbial pyrazine diamine is a novel electrolyte additive that shields high-voltage LiNi1/3Co1/3Mn1/3O2 cathodes

“…In the C 1s spectra, the pristine electrode showed characteristic peaks attributed to C–C (284.6 eV), C–O (285.6 eV), and CF 2 (290.4 eV) corresponding to active materials/conductive additive, adsorbed oxygen moieties on the surface of cathode, and fluoride-based binder 50 , 51 . Also, the presence of a weak C=O (287.3 eV) 51 was indicative of presence of surface films formed by the reaction with CO 2 with moisture to form lithium carbonate (Li 2 CO 3 ). However, after the electrochemical evaluation, carbonate (C=O, 287.2 and 288.0 eV) 51 was observed as an electrolyte decomposition product on the cathode surface in the case of control and DMBAP-based systems 51 .…”

“…Also, the presence of a weak C=O (287.3 eV) 51 was indicative of presence of surface films formed by the reaction with CO 2 with moisture to form lithium carbonate (Li 2 CO 3 ). However, after the electrochemical evaluation, carbonate (C=O, 287.2 and 288.0 eV) 51 was observed as an electrolyte decomposition product on the cathode surface in the case of control and DMBAP-based systems 51 . In the O 1s spectra, the pristine electrode showed a prominent lattice oxygen peak (531.6 eV), transition metal oxides peak (529.9 eV), and the decomposed carbonate species (534.9 eV).…”

Interfacial Engineering Strategy for High-Performance Zn Metal Anodes

“…Secondary batteries are a good choice, and their commercialization has provided great convenience to society [7,8]. Lithium-ion batteries currently dominate the commercial market, but their high-cost and safety issues, arising from the use of organic electrolytes, hinder their further development [9][10][11][12][13][14]. For example, the battery pack of a Boeing 787 aircraft ignited in 2013, a Samsung Note 7 mobile phone exploded in 2016, and a Tesla Model S electric car battery spontaneously ignited in 2019, all of which were caused by the flammability of organic electrolytes.…”

Microwave-Assisted Hydrothermal Synthesis of Space Fillers to Enhance Volumetric Energy Density of NMC811 Cathode Material for Li-Ion Batteries

“…Several attempts have been incorporated to achieve enhanced tap density values by variation of co-precipitation synthesis conditions, including pH [5], temperature [6], and the molar ratio of TM and complexing agent [6]. Apart from this, the shape [7] and sizes of the secondary particles [8] were tuned to obtain Ni-rich NMCs with proper tap density. Despite some progress, the ultimate values of tap density are already attained.…”