Research and progress analysis of battery 18650 rechargeablemanganese
battery materials
Lithium-ion batteries are the second generation of rechargeable green
batteries after nickel-cadmium batteries and metal hydride nickel batteries.
They are widely used in modern electronic equipment such as notebook computers,
mobile phones, laser pointers, and handheld cameras. Since the capacity of the
positive electrode material of this battery is lower than that of the negative
electrode material, further improvement in the capacity of lithium-ion batteries
is limited. battery 18650 rechargeablecobalt, battery 18650 rechargeablenickel
and battery 18650 rechargeablemanganese oxide materials are the three main
cathode materials for lithium-ion batteries. Among them, battery 18650
rechargeablemanganese oxide materials have a wide range of applications due to
their low preparation cost, no environmental pollution, and high effective
utilization rate of electrochemical specific capacity. Development and
application prospects, battery 18650 rechargeablemanganese batteries have become
the focus of widespread attention. In recent years, some achievements have been
made in the development and research of battery 18650 rechargeablemanganese
oxide cathode materials at home and abroad. This article is a brief review of
these achievements.
1Structure and properties of battery 18650 rechargeablemanganese oxide
materials
The main materials that can be used as cathode materials include spinel
structure LiMn2O4, Li2Mn4O9 and Li4Mn5O12, and layered structure LiMnO2. Some
structural characteristics and theoretical capacity of spinel structure battery
18650 rechargeablemanganese oxide are shown in Table 1.
Table 1 Structural characteristics and capacities of some spinel-type
battery 18650 rechargeablemanganese oxide compounds (where □ is an empty lattice
point)
In the spinel structure of battery 18650 rechargeablemanganese oxide,
battery 18650 rechargeableions are located at position 8a and oxygen atoms are
located at position 32e. During the charging and discharging process, there are
generally two platforms, about 4V and 3V. During the charge and discharge
process, due to the large change in the valence state of manganese, from +3
valence to +4 valence, there is a strong Jahn2Teller effect, causing the crystal
to change from cubic spinel type to tetragonal spinel type. During this phase
change process, the volume of the unit cell unit increased by 6.5%, causing the
spinel structure to deform, causing damage and attenuating the capacity.
Among spinel-structured battery 18650 rechargeablemanganese oxides, LiMn2O4
is currently the most studied and has the best performance as an electrode
material. In LiMn2O4, the Mn2O4 skeleton is a three-dimensional structure in
which tetrahedrons and octahedrons are coplanarly connected, which is beneficial
to Li+ diffusion, as shown in Figure 2.
Figure 2 LiMn2O4 crystal structure with spinel structure
Oxygen atoms are cubically closely packed, 75% of the Mn atoms are
alternately located between the cubically tightly packed oxygen layers, and the
remaining 25% are located in adjacent layers of Mn atoms. Therefore, in the
delithiated state, there are enough Mn cations present in each layer to maintain
the ideal cubic close-packed state of oxygen atoms. In LixMn2O4 formed during
the process of charging and inserting battery 18650 rechargeableions, when 0
In addition to the above spinel-type battery 18650 rechargeablemanganese
compounds, layered LiMnO2 compounds are now also found. One of them has a
different structure from layered LiCoO2 and belongs to the orthorhombic crystal
system. It charges and discharges at 2.5~4.3V and has reversible capacity. It is
about 200mAh/g. After the first charge and discharge, the orthorhombic LiMnO2
transforms into spinel LixMn2O4. There is also a structure similar to the
layered LiCoO2, which charges and discharges at low current between 4.3 and
3.4V, and has a reversible capacity of up to 270mAh/g. It will not transform
into spinel LixMn2O4 at about 3V, and has good structural stability during
charge and discharge.
Read recommendations:
602535 500MAH 3.7V
Analysis of the Causes of Lithium Battery Explosion.18650 lithium rechargeable battery
3.7v 2200mah 18650 lithium battery.Differences in 18650 lithium battery types
801538 battery company
CR927 battery