DE2232407C3 - Negative active mass for lead-acid batteries - Google Patents

Description

The invention relates to lead accumulators certain negative active mass, which consists essentially of Consists of lead and expanders

The spreading substances that are always present in the active mass of the negative electrodes of lead-acid batteries cause a large electrochemically active surface of the spongy lead and thus a high one Starting power of the lead-acid batteries. They also prevent the spongy lead from sintering in the case of cyclical Stress, so they contribute to maintaining the starting performance. They also help to reduce the Antimony poisoning of the minus plates, which leads to a reduced self-discharge of the minus plates and thus leads to an increased service life of the lead-acid battery.

Beside barium sulfate and soot as inorganic Sprcizsioffc are from the range of the organic Chemistry mainly uses lignin-based spreading agents

It is also from DE-PS 92 729 and from the article by E. J. Ritchie in the Journal of the Elektrochemical Society, Vol.100. No. 2 (1953), p 53 - 59 "Addition Agents for Negative Plates of Lead-Acid Storage Batteries" are known as quinones To use spreading agent. In many cases, however, the values achieved with these substances are above all satisfactory not with regard to the high current capacity

The object of the present invention is therefore to provide a negative active one intended for lead accumulators To indicate the mass, which relates to the high current behavior results in higher values than could be achieved with the expansion materials previously used in production.

This object is achieved according to the invention in that the negative active mass is used as spreading substances a combination of 0.05 to 0.4% by weight of lignin-based spreading agents and the 0.25 to 3-fold c

Table 1

Quinones as spreaders; Influence on high current capacities Additional amounts 0.20-0.25% to the minus mass

Amount, based on the amount of the lignin-based spreading substance, p-benzoquinone, quinhydrone or naphthoquinone contains

The lead-acid batteries with the negative active composition according to the invention are produced by the customary, generally known process. The usual starting materials for the active masses are separated according to polarity, mixed and made into a paste with sulfuric acid, the mixture for the negative active mass containing the spreading substance according to the invention. The active masses are then smeared into the grids, the plate grids of each polarity are put together in sets of plates and connected to one another. These plate sets are then formed, put together into plate packs and, after separators have been inserted, built into a block box in the usual way and this is then closed.
The most important influence of the spreading substances on the function of the accumulator is that on the high current capacities. Table 1 shows the results of the influence on the high-current capacities for the case in which the lead-acid battery contains one of the spreading substances alone. These results are shown in FIG. 1 is shown again graphically, the mean values of all measurements being plotted here, while the values given in Table 1 were obtained on the basis of an evaluation according to DIN 72 311. The figures given in Table 1 indicate the time in seconds after which the terminal voltage has dropped to half of the nominal voltage during the high-current discharge. The results show that the quinones used as spreading agents give high-current time values which are of the same order of magnitude as lignin-based spreading agents.

Without Quinone ') Chin Naphtho Normal Remarks additive hydron chinone ² ) Spreading
material) I H-18 (sec) I. 122 234 231 236 231 Cold high flow capacity at the start of the test (according to DIN) H-18 (sec) II 67 191 180 118 207 Cold high flow capacity after 60 cycles H + 27 (sec) I. 294 365 350 360 389 High current capacity at +27 ⁰ C at the start of the test H + 27 (sec) II 290 420 430 400 430 High current capacity at +27 ⁰ C after 60 cycles, ¹ I p-benzoquinone. ² S a -naphthoquinone. ³ ) lignin base.

Table 2 shows the results of the influence on the high current capacities when according to the invention as A combination of the previously used lignin-based on the one hand and various types of fuel Quinones, on the other hand, is used. These results are in Fig. 2 again shown graphically You can see how a combination usually reads used lignin-based spreading agent with the compounds p-benzoquinone, quinhydrone and naphtha

Table 2

Combination spreaders with quinone; Influence on high current capacities Dosages 0.1-0.2%

thoquinone has a beneficial effect on the high-current capacity. Here you get values that are about 10% above those that can be achieved with the normal lignin-based expander. That means that you get 10% can save on active negative ground, if you look at a value for the high current capacity x is satisfied that with the help of the spreading material uuf Lignin base is achieved. This in turn brings about a corresponding cost saving.

Without
additive

Normal
Spreading material ¹ )

K2

K3

Remarks

H-18 (sec) I. 104 228 252 251 247 see table I. H-18 (sec) II 66 150 142 147 180 H + 27 ° C (sec) I. 294 389 385 395 380 see table I. H + 27 ° C (sec) II 290 430 405 435 468

') Lignin base.

K 1 = combination of lignin spreading agent base with the addition of p-benzoquinone. K 2 = like K 1, but with addition of quinhydrone. K 3 = like K 1, but with the addition of naphthoquinone.

Such a synergetic effect as it is here surprisingly shows in a comparison of the results in Tables 1 and 2, was by no means a priori to be expected, especially since such connections as her above in Table 2 with K 1. K 2 and K 3 are designated. yes arise through an oxidative breakdown of the lignin and therefore show a relatively close relationship to the lignins. At best, values would be expected which correspond to the highest values of the individual components.

Other electrical values of lead buildings. how /. B. the charging characteristics and the load changed compared to the values shown with Lignin-based spreading agents. never or just insignificant.

For this purpose 2 sheets of drawings

Claims (1)

Claim: For lead accumulators certain negative active mass, which essentially consists of lead and expanding materials consists, characterized in that they are a combination of 0.05 to 0.4 as spreading substances % By weight of lignin-based spreading agents and 0.25 to 3 times the amount, in particular the same Amount, based on the amount of the lignin-based spreading substance, p-benzoquinone, quinhydron or Contains naphthoquinone